LCModel output from 32 GA baby

Understanding the long-term consequences of prematurity

LCModel output from 32 GA baby

Children’s National Health System researchers processed H1-MRS data using LCModel software to calculate absolute metabolite concentrations for N-acetyl-aspartate (NAA), choline (Cho) and creatine (Cr). Preterm infants had significantly lower cerebellar NAA (p=<0.025) and higher Cho (p=<0.001) when compared with healthy term-equivalent infants. The area of the brain within the red box is the cerebellum, the region of interest for this study.

Premature birth, a condition that affects approximately 10 percent of births in the United States, often is accompanied by health problems ranging from difficulties breathing and eating to long-term neurocognitive delays and disabilities. However, the reasons for these problems have been unclear.

In a study published online Aug. 15, 2017 in Scientific Reports, a team of Children’s National Health System clinician-researchers reports that prematurity is associated with altered metabolite profiles in the infants’ cerebellum, the part of the brain that controls coordination and balance. Pre-term infants in the study had significantly lower levels of a chemical marker of nerve cell integrity and significantly higher concentrations of a chemical marker of cellular membrane turnover.

“These data suggest that interrupting the developing fetal brain’s usual growth plan during gestation – which can occur through early birth, infection or experiencing brain damage – might trigger a compensatory mechanism. The infant’s brain tries to make up for lost time or heal injured tissue by producing a certain type of cells more quickly than it normally would,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National and senior study author. “The more sensitive imaging technique that we used also revealed nerve cell damage from brain injuries extends beyond the site of injury, a finding that contrasts with what is found through conventional magnetic resonance imaging (MRI).”

It has long been clear that prematurity – birth before 37 weeks gestation – is accompanied by a number of immediate and long-term complications, from potential problems breathing and feeding at birth to impairments in hearing and sight that can last throughout an individual’s life.

Neurocognitive developmental delays often accompany pre-term birth, many of which can have long-lasting consequences. Studies have shown that children born prematurely are more likely to struggle in school, have documented learning disabilities and experience significant delays in developing gross and fine motor skills compared with children born at full-term.

Several studies have investigated the root cause of these issues in the cerebrum, the structure that takes up the majority of the brain and is responsible for functions including learning and memory, language and communication, sensory processing and movement. However, the cerebellum – a part of the brain that plays an important role in motor control – has not received as much research attention.

In the new study, Limperopoulos and colleagues used a specialized MRI technique that allowed them to parse out differences in which molecules are present in the cerebellum of full-term infants compared with premature infants. Their findings show a variety of differences that could offer clues to explain developmental differences between these two populations – and potentially identify ways to intervene to improve outcomes.

The researchers recruited 59 premature infants, born at 32 or fewer weeks’ gestation, and 61 healthy, full-term infants. Each baby received a special type of MRI known as proton magnetic resonance spectroscopy, or H1-MRS, that measures the concentrations of particular molecules in the brain. The full-term infants had these MRIs shortly after birth; the pre-term infants had them at 39 to 41 weeks gestational age, or around the time that they would have been born had the pregnancy continued to term.

Looking specifically at the cerebellum, the researchers found that the pre-term infants overall had significantly lower concentrations of N-acetyl-aspartate (NAA), a marker of the integrity of nerve cells. They also had significantly higher concentrations of choline, a marker of cell membrane integrity and membrane turnover.

Concentrations of creatine, a marker of stores of cellular energy, were about the same overall between the two groups. However, the researchers found that brain injuries, which affected 35 of the pre-term infants but none of the full-term infants, were associated with significantly lower concentrations of NAA, choline and creatine. Having a neonatal infection, which affected 21 of the pre-term infants but none of the full-term ones, was associated with lower NAA and creatine.

The findings could offer insight into exactly what’s happening in the brain when infants are born pre-term and when these vulnerable babies develop infections or their brains become injured – conditions that convey dramatically higher risks for babies born too early, Limperopoulos says. The differences between the full-term babies and the pre-term ones reflect disturbances these cells are experiencing at a biochemical level, she explains.

Limperopoulos and colleagues note that more research will be necessary to connect these findings to what is already known about developmental problems in pre-term infants. Eventually, she says, scientists might be able to use this knowledge to develop treatments that might be able to change the course of brain development in babies born too early, getting them on track with infants born at term.

“We know that the bodies of pre-term infants demonstrate a remarkable ability to catch up with peers who were born at full-term, in terms of weight and height. Our challenge is to ensure that preemies’ brains also have an opportunity to develop as normally as possible to ensure optimal long-term outcomes,” Limperopoulos says.

Catherine Limperopoulos

A closer look at the placenta to predict FGR

Catherine Limperopoulos

Using three-dimensional magnetic resonance imaging, a Children’s National research team that included Catherine Limperopoulos, Ph.D., characterized the shape, volume, morphometry and texture of placentas during pregnancy and, using a novel framework, predicted with high accuracy which pregnancies would be complicated by fetal growth restriction.

Early in development, cells from the fertilized egg form the placenta, a temporary organ that serves as an interface between the mother and her growing offspring. When things go right, as occurs in the vast majority of pregnancies, the placenta properly delivers nutrients from the mother’s diet and oxygen from the air she breathes to the developing fetus while siphoning away its waste products. This organ also plays important immune-modulating and endocrine roles.

However, in a number of pregnancies, the placenta does not do an adequate job. Unable to effectively serve the fetus, a variety of adverse conditions can develop, including preeclampsia, fetal growth restriction (FGR), preterm birth and even fetal death.

Despite the key role that the placenta plays in fetal health, researchers have few non-invasive ways to assess how well it works during pregnancy. In fact, placental disease might not be suspected until very late.

In a new study, a team of Children’s National Health System research scientists is beginning to provide insights into the poorly understood placenta.

Using three-dimensional (3D) magnetic resonance imaging (MRI), the research team characterized the shape, volume, morphometry and texture of placentas during pregnancy and, using a novel framework, predicted with high accuracy which pregnancies would be complicated by FGR.

“When the placenta fails to carry out its essential duties, both the health of the mother and fetus can suffer and, in extreme cases, the fetus can die. Because there are few non-invasive tools that reliably assess the health of the placenta during pregnancy, unfortunately, placental disease may not be discovered until too late – after impaired fetal growth already has occurred,” says Catherine Limperopoulos, Ph.D., co-director of research in the Division of Neonatology at Children’s National Health System and senior author of the study published online July 22 in Journal of Magnetic Resonance Imaging. “Identifying early biomarkers of placental disease that may impair fetal growth and well-being open up brand-new opportunities to intervene to protect vulnerable fetuses.”

The Children’s research team acquired 124 fetal scans from 80 pregnancies beginning at the 18th gestational week and continuing through the 39th gestational week. Forty-six women had normal pregnancies and healthy fetuses while 34 women’s pregnancies were complicated by FGR, defined by estimated fetal weight that fell below the 10th percentile for gestational age. The placenta was described by a combination of shape and textural features. Its shape was characterized by three distinct 3D features: Volume, thickness and elongation. Its texture was evaluated by three different sets of textural features computed on the entire placenta.

“The proposed machine learning-based framework distinguished healthy pregnancies from FGR pregnancies with 86 percent accuracy and 87 percent specificity. And it estimated the birth weight in both healthy and high-risk fetuses throughout the second half of gestation reasonably well,” says the paper’s lead author, Sonia Dahdouh, Ph.D., a research fellow in Children’s Developing Brain Research Laboratory.

“We are helping to pioneer a very new frontier in fetal medicine,” Limperopoulos adds. “Other studies have developed prediction tools based on fetal brain features in utero. To our knowledge, this would be the first proposed framework for semi-automated diagnosis of FGR and estimation of birth weight using structural MRI images of the placental architecture in vivo. This has the potential to address a sizable clinical gap since we lack methods that are both sufficiently sensitive and specific to reliably detect FGR in utero.”

The research team writes that its findings underscore the importance of future studies on a larger group of patients to expand knowledge about underlying placenta mechanisms responsible for disturbed fetal growth, as well as to more completely characterize other potential predictors of fetal/placental development in high-risk pregnancies, such as genetics, physiology and nutrition.

Zhe Han, PhD

Lab led by Zhe Han, Ph.D., receives $1.75 million from NIH

Zhe Han, PhD

A new four-year NIH grant will enable Zhe Han, Ph.D., to carry out the latest stage in the detective work to determine how histone-modifying genes regulate heart development and the molecular mechanisms of congenital heart disease caused by these genetic mutations.

The National Institutes of Health (NIH) has awarded $1.75 million to a research lab led by Zhe Han, Ph.D., principal investigator and associate professor in the Center for Genetic Medicine Research, in order to build models of congenital heart disease (CHD) that are tailored to the unique genetic sequences of individual patients.

Han was the first researcher to create a Drosophila melanogaster model to efficiently study genes involved in CHD, the No.1 birth defect experienced by newborns, based on sequencing data from patients with the heart condition. While surgery can fix more than 90 percent of such heart defects, an ongoing challenge is how to contend with the remaining cases since mutations of a vast array of genes could trigger any individual CHD case.

In a landmark paper published in 2013 in the journal Nature, five different institutions sequenced the genomes of more than 300 patients with CHD and their families, identifying 200 mutated genes of interest.

“Even though mutations of these genes were identified from patients with CHD, these genes cannot be called ‘CHD genes’ since we had no in vivo evidence to demonstrate these genes are involved in heart development,” Han says. “A key question to be answered: How do we efficiently test a large number of candidate disease genes in an experimental model system?”

In early 2017, Han published a paper in Elife providing the answer to that lingering question. By silencing genes in a fly model of human CHD, the research team confirmed which genes play important roles in development. The largest group of genes that were validated in Han’s study were histone-modifying genes. (DNA winds around the histone protein, like thread wrapped around a spool, to become packed into a higher-level structure.)

The new four-year NIH grant will enable Han to carry out the next stage of the detective work to determine precisely how histone-modifying genes regulate heart development. In order to do so, his group will silence the function of histone-modifying genes one by one, to study their function in the fly heart development and to identify the key histone-modifying genes for heart development. And because patients with CHD can have more than one mutated gene, he will silence multiple genes simultaneously to determine how those genes work in partnership to cause heart development to go awry.

By the end of the four-year research project, Han hopes to be able to identify all of the histone-modified genes that play pivotal roles in development of the heart in order to use those genes to tailor make personalized fly models corresponding to individual patient’s genetic makeup.

Parents with mutations linked to CHD are likely to pass heart disease risk to the next generation. One day, those parents could have an opportunity to sequence their genes to learn the degree of CHD risk their offspring face.

“Funding this type of basic research enables us to understand which genes are important for heart development and how. With this knowledge, in the near future we could predict the chances of a baby being born with CHD, and cure it by using gene-editing approaches to prevent passing disease to the next generation,” Han says.

Spectral data shine light on placenta

preemie baby

A research project led by Subechhya Pradhan, Ph.D., aims to shed light on metabolism of the placenta, a poorly understood organ, and characterize early biomarkers of fetal congenital heart disease.

The placenta serves as an essential intermediary between a pregnant mother and her developing fetus, transporting in life-sustaining oxygen and nutrients, ferrying out waste and serving as interim lungs, kidneys and liver as those vital organs develop in utero.

While the placenta plays a vital role in supporting normal pregnancies, it remains largely a black box to science. A research project led by Subechhya Pradhan, Ph.D., and partially funded by a Clinical and Translational Science Institute Research Award aims to shed light on placenta metabolism and characterize possible early biomarkers of impaired placental function in fetal congenital heart disease (CHD), the most common type of birth defect.

“There is a huge information void,” says Pradhan, a research faculty member of the Developing Brain Research Laboratory at Children’s National Health System. “Right now, we do not have very much information about placenta metabolism in vivo. This would be one of the first steps to understand what is actually going on in the placenta at a biochemical level as pregnancies progress.”

The project Pradhan leads will look at the placentas of 30 women in the second and third trimesters of healthy, uncomplicated pregnancies and will compare them with placentas of 30 pregnant women whose fetuses have been diagnosed with CHD. As volunteers for a different study, the women are already undergoing magnetic resonance imaging, which takes detailed images of the placenta’s structure and architecture. The magnetic resonance spectroscopy scans that Pradhan will review show the unique chemical fingerprints of key metabolites: Choline, lipids and lactate.

Choline, a nutrient the body needs to preserve cellular structural integrity, is a marker of cell membrane turnover. Fetuses with CHD have higher concentrations of lactate in the brain, a telltale sign of a shortage of oxygen. Pradhan’s working hypothesis is that there may be differing lipid profiles and lactate levels in the placenta in pregnancies complicated by CHD.  The research team will extract those metabolite concentrations from the spectral scans to describe how they evolve in both groups of pregnant women.

“While babies born with CHD can undergo surgery as early as the first few days (or sometimes hours) of life to correct their hearts, unfortunately, we still see a high prevalence of neurodevelopmental impairments in infants with CHD. This suggests that neurological dysfunctional may have its origin in fetal life,” Pradhan says.

Having an earlier idea of which fetuses with CHD are most vulnerable has the potential to pinpoint which pregnancies need more oversight and earlier intervention.

Placenta spectral data traditionally have been difficult to acquire because the pregnant mother moves as does the fetus, she adds. During the three-minute scans, the research team will try to limit excess movement using a technique called respiratory gating, which tells the machine to synchronize image acquisition so it occurs in rhythm with the women’s breathing.

Baby with Cleft Palate

Understanding genetic synergy in cleft palate

Baby with Cleft Palate

Like mechanics fixing a faulty engine, Youssef A. Kousa, M.S., D.O., Ph.D., says researchers will not be able to remedy problems related to IRF6, a gene implicated in cleft palate, until they better understand how the gene works.

Like all of the individual elements of fetal development, palate growth is a marvel of nature. In part of this process, ledges of tissue on the sides of the face grow downwards on each side of the tongue, then upward, fusing at the midline at the top of the mouth. The vast majority of the time, this process goes correctly. However, some part of it goes awry for the 2,650 babies born in the United States each year with cleft palates and the thousands more born worldwide with the defect.

For nearly two decades, researchers have known that a gene known as IRF6 is involved in palate formation. Studies have shown that this gene contributes about 12 percent to 18 percent of the risk of cleft palate, more than any other gene identified thus far. IRF6 is active in epithelial tissues – those that line cavities and surfaces throughout the body – including the periderm, a tissue that lines the mouth cavity and plays an important role during development.

According to Youssef A. Kousa, M.S., D.O., Ph.D., a child neurology fellow at Children’s National Health System, the periderm acts like a nonstick layer, preventing the tongue or other structures from adhering to the growing palate and preventing it from sealing at the midline. While researchers have long suspected that IRF6 plays a strong role in promoting this nonstick quality, exactly how it exerts its influence has not been clear.

“Gaining a better understanding of this gene might help us to eventually address deficits or perturbations in the system that creates the palate,” Dr. Kousa says. “Like a mechanic fixing a faulty engine, we will not be able to remedy problems related to this gene until we know how the gene works.”

Youssef Kousa

“Gaining a better understanding of this gene might help us to eventually address deficits or perturbations in the system that creates the palate,” Dr. Kousa says. “Like a mechanic fixing a faulty engine, we will not be able to remedy problems related to this gene until we know how the gene works.”

In a study published July 19, 2017 by the Journal of Dental Research, Dr. Kousa and colleagues seek to decipher one piece of this puzzle by investigating how this key gene might interact with others that are active during fetal development. The researchers were particularly interested in genes that work together in a cascade of activity known as the tyrosine kinase receptor signaling pathway.

Because this pathway includes a large group of genes, Dr. Kousa and colleagues reasoned that they could answer whether IRF6 interacts with this pathway by looking at whether the gene interacts with the last member of the cascade, a gene called SPRY4. To do this, the researchers worked with experimental models that had mutations in IRF6, SPRY4 or both. If these two genes interact, the scientists hypothesized, carrying mutations in both genes at the same time should result in a dramatically different outcome compared with animals that carried mutations in just one gene.

Using selective breeding techniques, the researchers created animals that had mutations in either of these genes or in both. Their results suggest that IRF6 and SPRY4 indeed do interact: Significantly more of the oral surface was adhered to the tongue during fetal development in experimental models that had mutations in both genes compared with those that had just one single gene mutated. Examining the gene activity in the periderm cells of these affected animals, the researchers found that doubly mutated experimental models also had decreased activity in a third gene known as GRHL3, which also has been linked with cleft lip and palate.

Dr. Kousa says the research team plans to continue exploring this interaction to better understand the flow of events that lead from perturbations in these genes to formation of cleft palate. Some of the questions they would like to answer include exactly which gene or genes in the tyrosine kinase receptor signaling pathway specifically interact with IRF6 – since SPRY4 represents just the end of that pathway, others genes earlier in the pathway are probably the real culprits responsible for driving problems in palate formation. They also will need to verify if these interactions take place in humans in the same way they occur in preclinical models.

Eventually, Dr. Kousa adds, the findings could aid in personalized prenatal counseling, diagnosis and screening related to cleft palate, as well as preventing this condition during pregnancy. Someday, doctors might be able to advise couples who carry mutations in these genes about whether they are more likely to have a baby with a cleft palate or determine which select group of pregnancies need closer monitoring. Additionally, because research suggests that GRHL3 might interact with nutrients, including inositol, it might be possible to prevent some cases of cleft palate by taking additional supplements during pregnancy.

“The more we know about how these genes behave,” Dr. Kousa says, “the more we can potentially avoid fetal palate development going down the wrong path.”

Kazue Hashimoto-Torii and Masaaki Torii

Center for Neuroscience Research investigators join CIFASD

Kazue Hashimoto-Torii and Masaaki Torii, Collaborative Initiative on Fetal Alcohol Spectrum Disorders

Masaaki Torii, Ph.D., Kazue Hashimoto-Torii, Ph.D., and their research teams are joining Collaborative Initiative on Fetal Alcohol Spectrum Disorders, a consortium supported by the National Institutes of Health.

Kazue Hashimoto-Torii, Ph.D., Masaaki Torii, Ph.D., and the research teams they lead have joined a national research consortium for Fetal Alcohol Spectrum Disorders that is supported by the National Institutes of Health (NIH).

The Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD) aims to leverage multidisciplinary approaches to develop effective interventions and treatments for Fetal Alcohol Spectrum Disorders.

“Both of our labs have been fortunate in receiving multiple R series research grants from the NIH. I am deeply honored that we now join this prestigious national consortium, which opens additional opportunities to collaborate with other labs with neurobehavioral, genetics and facial dysmorphology expertise as well as other specialized disciplines,” says Hashimoto-Torii, principal investigator in the Center for Neuroscience Research at Children’s National Health System.

Fetal Alcohol Spectrum Disorders are a constellation of conditions that result from exposure to alcohol in the womb that reflect the vastly different ways fetuses respond to that in utero insult. While early intervention is crucial, one challenge that continues to bedevil the field is trying to determine which pregnancies are most at risk.

“It is crucial to develop early and precise biomarkers for predicting children’s risk for cognitive and behavioral problems,” Hashimoto-Torii says. “Our labs will work on developing a novel approach for identifying such biomarkers.”

The Children’s researchers will examine epigenetic changes at the single cell level that may provide the earliest hint of cognitive and learning difficulties – long before children show any symptoms of such problems. Hashimoto-Torii’s lab will perform single-cell droplet digital polymerase chain reaction (PCR) based biomarker analysis of blood samples from experimental models and humans. Meanwhile, the lab run by Torii – also a principal investigator in the Center for Neuroscience Research – will collect blood samples from experimental models, perform comprehensive behavioral analysis, and evaluate potential correlations between behaviors seen in the experimental models and their drop-PCR results.

“Under the auspices of CIFASD, we ultimately hope to link these biomarkers from our lab with results that our colleagues are seeing in children in order to validate their ability to accurately predict outcomes from prenatal alcohol exposure,” she says.

zika virus

Will the Zika epidemic re-emerge in 2017?

Anthony Fauci

Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health, discussed the possibility of a reemergence of Zika virus at Children’s National Research and Education Week.

Temperatures are rising, swelling the population of Aedes mosquitoes that transmit the Zika virus and prompting an anxious question: Will the Zika epidemic re-emerge in 2017?

Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases at the National Institutes of Health (NIH), sketched out contrasting scenarios. Last year in Puerto Rico, at least 13 percent of residents were infected with Zika, “a huge percentage of the population to get infected in any one outbreak,” Dr. Fauci says. But he quickly adds: “That means that 87 percent of the population” did not get infected. When the chikungunya virus swept through the Caribbean during an earlier outbreak, it did so in multiple waves. “We are bracing for a return of Zika, but we shall see what happens.” Dr. Fauci says.

When it comes to the continental United States, however, previous dengue and chikungunya outbreaks were limited to southern Florida and Texas towns straddling the Mexican border. Domestic Zika transmission last year behaved in much the same fashion.

“Do we think we’re going to get an outbreak [of Zika] that is disseminated throughout the country? The answer is no,” Dr. Fauci adds. “We’re not going to see a major Puerto Rico-type outbreak in the continental United States.”

Dr. Fauci’s remarks were delivered April 24 to a standing-room-only auditorium as part of Research and Education Week, an annual celebration of the cutting-edge research and innovation happening every day at Children’s National. He offered a sweeping, fact-filled summary of Zika’s march across the globe: The virus was first isolated from a primate placed in a treehouse within Uganda’s Zika forest to intentionally become infected; Zika lurked under the radar for the first few decades, causing non-descript febrile illness; it bounced from country to country, causing isolated outbreaks; then, it transformed into an infectious disease of international concern when congenital Zika infection was linked to severe neural consequences for babies born in Brazil.

zika virus

Zika virus lurked under the radar for several decades, causing non-descript febrile illness; it bounced from country to country, resulting in isolated outbreaks; then, it transformed into an infectious disease of international concern.

“I refer to Brazil and Zika as the perfect storm,” Dr. Fauci told attendees. “You have a country that is a large country with a lot of people, some pockets of poverty and economic depression –  such as in the northeastern states –  without good health care there, plenty of Aedes aegypti mosquitoes and, importantly, a totally immunologically naive population. They had never seen Zika before. The right mosquitoes. The right climate. The right people. The right immunological status. And then, you have the explosion in Brazil.”

In Brazil, 139 to 175 babies were born each year with microcephaly – a condition characterized by a smaller than normal skull – from 2010 to 2014. From 2015 through 2016, that sobering statistic soared to 5,549 microcephaly cases, 2,366 of them lab-confirmed as caused by Zika.

Microcephaly “was the showstopper that changed everything,” says Dr. Fauci. “All of a sudden, [Zika] went from a relatively trivial disease to a disease that had dire consequences if a mother was infected, particularly during the first trimester.”

As Zika infections soared, ultimately affecting more than 60 countries, the virus surprised researchers and clinicians a number of times, by:

  • Being spread via sex
  • Being transmitted via blood transfusion, a finding from Brazil that prompted the Food and Drug Administration to recommend testing for all U.S. donated blood and blood products
  • Decimating developing babies’ neural stem cells and causing a constellation of congenital abnormalities, including vision problems and contractions to surviving infants’ arms and legs
  • Causing Guillain-Barré syndrome
  • Triggering transient hearing loss
  • Causing myocarditis, heart failure and arrhythmias

When it comes to the U.S. national response, Dr. Fauci says one of the most crucial variables is how quickly a vaccine becomes available to respond to the emerging outbreak. For Zika, the research community was able to sequence the virus and launch a Phase I trial in about three months, “the quickest time frame from identification to trial in the history of all vaccinology,” he adds.

Zika is a single-stranded, enveloped RNA virus that is closely related to dengue, West Nile, Japanese encephalitis and Yellow fever viruses, which gives the NIH and others racing to produce a Zika vaccine a leg up. The Yellow fever vaccine, at 99 percent effectiveness, is one of the world’s most effective vaccines.

“I think we will wind up with an effective vaccine. I don’t want to be over confident,” Dr. Fauci  says. “The reason I say I believe that we will is because [Zika is] a flavivirus, and we have been able to develop effective flavivirus vaccines. Remember, Yellow fever is not too different from Zika.”

Sarah Mulkey Columbia Zika Study

Damage may lurk in “normal” Zika-exposed brains

Sarah Mulkey Columbia Zika Study

An international study that includes Sarah B. Mulkey, M.D., Ph.D., aims to answer one of the most vexing questions about Zika: If babies’ brains appear “normal” at birth, have they survived Zika exposure in the womb with few neurological repercussions? Dr. Mulkey presented preliminary findings at PAS2017.

It has been well established by researchers, including scientists at Children’s National Health System, that the Zika virus is responsible for a slew of birth defects – such as microcephaly, other brain malformations and retinal damage – in babies of infected mothers. But how the virus causes these often devastating effects, and who exactly is affected, has not been explained fully.

Also unknown is whether exposed babies that appear normal at birth are truly unaffected by the virus or have hidden problems that might surface later. The majority of babies born to Zika-infected mothers in the United States appear to have no evidence of Zika-caused birth defects, but that’s no guarantee that the virus has not caused lingering damage.

Recently, Sarah B. Mulkey, M.D., Ph.D., made a trip to Colombia, where Children’s National researchers are collaborating on a clinical study. There, she tested Zika-affected babies’ motor skills as they sat, stood and lay facing upward and downward. The international study aims to answer one of the most vexing questions about Zika: If babies’ brains appear “normal” at birth, have they survived Zika exposure in the womb with few neurological repercussions?

“We don’t know the long-term neurological consequences of having Zika if your brain looks normal,” says Dr. Mulkey, a fetal-neonatal neurologist who is a member of Children’s Congenital Zika Virus Program. “That is what’s so scary, the uncertainty about long-term outcomes.”

According to the Centers for Disease Control and Prevention (CDC), one in 10 pregnancies across the United States with laboratory-confirmed Zika virus infection results in birth defects in the fetus or infant. For the lion’s share of Zika-affected pregnancies, then, babies’ long-term prospects remain a mystery.

“This is a huge number of children to be impacted and the impact, as we understand, has the potential to be pretty significant,” Dr. Mulkey adds.

Dr. Mulkey, the lead author, presented the research group’s preliminary findings during the 2017 annual meeting of the Pediatric Academic Societies (PAS). The presentation was one of several that focused on the Zika virus. Roberta L. DeBiasi, M.D., M.S., chief of the Division of Pediatric Infectious Diseases at Children’s National, organized two invited symposia devoted to the topic of Zika: Clinical perspectives and knowledge gaps; and the science of Zika, including experimental models of disease and vaccines. Dr. DeBiasi’s presentation included an overview of the 68 Zika-exposed or infected women and infants seen thus far by Children’s multidisciplinary Congenital Zika Virus Program.

“As the world’s largest pediatric research meeting, PAS2017 is an ideal setting for panelists to provide comprehensive epidemiologic and clinical updates about the emergence of Congenital Zika Syndrome and to review the pathogenesis of infection as it relates to the fetal brain,” Dr. DeBiasi says. “With temperatures already rising to levels that support spread of the Aedes mosquito, it is imperative for pediatricians around the world to share the latest research findings to identify the most effective interventions.”

As one example, Dr. Mulkey’s research sought to evaluate the utility of using magnetic resonance imaging (MRI) to evaluate fetal brain abnormalities in 48 babies whose mothers had confirmed Zika infection during pregnancy. Forty-six of the women/infant pairs enrolled in the prospective study are Colombian, and two are Washington, D.C. women who were exposed during travel to a Zika hot zone.

The women were infected with Zika during all three trimesters and experienced symptoms at a mean gestational age of 8.4 weeks. The first fetal MRIs were performed as early as 18 weeks’ gestation. Depending upon the gestational age when they were enrolled in the study, the participants had at least one fetal MRI as well as serial ultrasounds. Thirty-six fetuses had a second fetal MRI at about 31.1 gestational weeks. An experienced pediatric neuroradiologist evaluated the images.

Among the 48 study participants, 45 had “normal” fetal MRIs.

Three fetuses exposed to Zika in the first or second trimester had abnormal fetal MRIs:

  • One had heterotopia and an early, abnormal fold on the surface of the brain, indications that neurons did not migrate to their anticipated destination during brain development. This pregnancy was terminated at 23.9 gestational weeks.
  • One had parietal encephalocele, a rare birth defect that results in a sac-like protrusion of the brain through an opening in the skull. According to the CDC, this defect affects one in 12,200 births, or 340 babies, per year. It is not known if this rare finding is related to Zika infection.
  • One had a thin corpus callosum, dysplastic brainstem, heterotopias, significant ventriculomegaly and generalized cerebral/cerebellar atrophy.

“Fetal brain MRI detected early structural brain changes in fetuses exposed to the Zika virus in the first and second trimester,” Dr. Mulkey says. “The vast majority of fetuses exposed to Zika in our study had normal fetal MRI, however. Our ongoing study, underwritten by the Thrasher Research Fund, will evaluate their long-term neurodevelopment.”

Adré J. du Plessis, MB.Ch.B., M.P.H., director of the Fetal Medicine Institute and senior author of the paper, notes that this group “is a very important cohort to follow as long as Dr. Mulkey’s funding permits. We know that microcephaly is among the more devastating side effects caused by Zika exposure in utero. Unanswered questions remain about Zika’s impact on hearing, vision and cognition for a larger group of infants. Definitive answers only will come with long-term follow-up.”

Many of the Colombian families live in Sabanalarga, a relatively rural, impoverished area with frequent rain, leaving pockets of fresh water puddles that the mosquito that spreads Zika prefers, Dr. Mulkey adds. Families rode buses for hours for access to fetal MRI technology, which is not common in Colombia.

“The mothers are worried about their babies. They want to know if their babies are doing OK,” she says.

Catherine Limperopoulous

The brain’s fluid-filled spaces during growth

Catherine Limperopoulous

Catherine Limperopoulous, Ph.D., and her colleagues used volumetric MRIs to assess how the ventricles, cerebrospinal fluid and the rest of the fetal brain normally change over time.

The human brain is not one solid mass. Buried within its gray and white matter are a series of four interconnected chambers, called ventricles, which produce cerebrospinal fluid. These ventricles are readily apparent on the fetal ultrasounds that have become the standard of prenatal care in the United States and most developed countries around the world. Abnormalities in the ventricles’ size or shape – or both – can give doctors an early warning that fetal brain development might be going awry.

But what is abnormal? It is not always clear, says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National Health System. Limperopoulos explains that despite having many variations in fetal ventricles, some infants have completely normal neurodevelopmental outcomes later. On the other hand, some extremely subtle variations in shape and size can signal problems.

On top of these complications are the tools clinicians typically use to assess the ventricles. Limperopoulos explains that most early indications of ventricle abnormalities come from ultrasounds, but the finer resolution of magnetic resonance imaging (MRI) can provide a more accurate assessment of fetal brain development. Still, both standard MRI and ultrasound provide only two-dimensional pictures, making it difficult to quantify slight differences in the volume of structures.

To help solve these problems, Limperopoulos and her colleagues recently published a paper in Developmental Neuroscience that takes a different tack. The team performed volumetric MRIs – a technique that provides a precise three-dimensional measure of structural volumes – on the brains of healthy fetuses to assess how the ventricles, cerebrospinal fluid and the rest of the brain normally change over time. Limperopoulos’ team recently performed a similar study to assess normal volumetric development in the brain’s solid tissues.

Previous studies published on comparable topics typically used information gathered from subjects who initially had clinical concerns but eventually were dismissed from these studies for not having worrisome diagnoses in the end. This might not truly reflect a typical population of pregnant women, Limperopoulos says.

Working with 166 pregnant women with healthy pregnancies spanning from 18 to 40 weeks gestation, the researchers performed volumetric MRIs on their singleton fetuses that covered every week of this second half of pregnancy. This technique allowed them to precisely calculate the volumes of structures within the fetal brain and get an idea of how these volumes changed over time within the group.

Their results show that over the second and third trimester:

  • The lateral ventricles, the largest ventricles found in the cerebrum with one for each brain hemisphere, grew about two-fold;
  • The third ventricle, found in the forebrain, grew about 23-fold;
  • The fourth ventricle, found in the hindbrain, grew about eight-fold;
  • And the extra-axial cerebrospinal fluid, found under the lining of the brain, increased about 11-fold.

The total brain volume increased 64-fold over this time, with the parenchyma – the solid brain tissue that encompasses gray and white matter – growing significantly faster than the cerebrospinal fluid-filled spaces.

Limperopoulos points out that the ability to measure the growth of the brain’s fluid-filled spaces relative to the surrounding brain tissue can provide critical information to clinicians caring for developing fetuses. In most cases, knowing what is normal allows doctors to reassure pregnant women that their fetus’ growth is on track. Abnormalities in these ratios can provide some of the first signals to alert doctors to blockages in cerebrospinal fluid flow, abnormal development, or the loss of brain tissue to damage or disease. Although the neurodevelopmental outcomes from each of these conditions can vary significantly, traditional ultrasounds or MRIs might not be able to distinguish these possibilities from each other. Being able to differentiate why cerebrospinal fluid spaces have abnormal shapes or sizes might allow doctors to better counsel parents, predict neurological outcomes, or potentially intervene before or after birth to mitigate brain damage.

“By developing a better understanding of what’s normal,” Limperopoulos says, “we can eventually identify reliable biomarkers of risk and guide interventions to minimize risks for vulnerable fetuses.”

Kazue Hashimoto Torii

A brain’s protector may also be its enemy

Kazue Hashimoto Torii

By looking back to the earliest moments of embryonic brain development, Kazue Hashimoto-Torii, Ph.D. and her collaborators sought to explain the molecular and cellular bases for complex congenital brain disorders that can result from exposure to harmful agents.

When the brain is exposed to an environmental stressor all is not immediately lost. Brain cells have mechanisms that protect them against the ravages of alcohol and other toxic substances. One of these is a protein the cells make, known as Heat Shock Factor 1 (Hsf1), which helps to shield them from damage. The fetal brain also can make Hsf1, which protects its particularly vulnerable cells from environmental stressors that pregnant mothers are exposed to during gestation.

However, a new study suggests that this system is not perfect. Research led by Children’s National Health System scientists suggests that when too much Hsf1 is produced, it actually can impair the brain during development. While this finding was made in a preclinical model, it raises questions about neural risks for human infants if their mothers drink alcohol in the first or second trimester of pregnancy.

When fetuses are chronically exposed to harmful agents such as alcohol, ethanol or methyl mercury in utero, the experience can negatively affect fetal brain development in unpredictable ways. Some fetal brains show little or no damage, while others suffer severe damage. By looking at the earliest moments of embryonic brain development, an international research team that includes five Children’s National authors sought to explain the molecular and cellular bases for complex congenital brain disorders that can result from exposure to such harmful agents.

“From a public health perspective, there is ongoing debate about whether there is any level of drinking by pregnant women that is ‘safe,’ ” says Kazue Hashimoto-Torii, Ph.D., principal investigator in the Center for Neuroscience Research at Children’s National and senior author of the paper published May 2 in Nature Communications. “We gave ethanol to pregnant preclinical models and found their offspring’s neural cells experienced widely differing responses to this environmental stress. It remains unclear which precise threshold of stress exposure represents the tipping point, transforming what should be a neuroprotective response into a damaging response. Even at lower levels of alcohol exposure, however, the risk for fetal neural cells is not zero,” Hashimoto-Torii adds.

The cerebral cortex – the thin outer layer of the cerebrum and cerebellum that enables the brain to process information – is particularly vulnerable to disturbances in the womb, the study authors write. To fend off insult, neural cells employ a number of self-preservation strategies, including launching the protective Hsf1-Heat shock protein (Hsp) signaling pathway that is used by a wide range of organisms, from single-cell microbes to humans. Developing fetuses activate Hsf1-Hsp signaling upon exposure to environmental stressors, some to no avail.

To help unravel the neurological mystery, the researchers used a method that allows a single molecule to fluoresce during stress exposure. They tapped specific environmental stressors, such as ethanol, hydrogen peroxide and methyl mercury – each of which are known to produce oxidative stress at defined concentrations. And, using an experimental model, they examined the Hsf1 activation pattern in the developing cerebral cortex by creating a marker, an encoding gene tagged with a type of fluorescent protein that makes it glow bright red.

“Our results suggest that heterogeneous events of abnormal brain development may occur probabilistically – which explains patterns of cortical malformations that vary with each individual, even when these individuals are exposed to similar levels of environmental stressors,” Hashimoto-Torii adds.

Among the more striking findings, neural cells with excessively high levels of Hsf1-Hsp activation due to ethanol exposure experience disruptions to normal development, with delayed migration by immature cortical neurons. For the fetal brain to develop normally, neurons need to migrate to precise places in the brain at just the right time to enable robust neural connections. When neurons fail to arrive at their destinations or get there too late, there can be gaps in the neural network, compromising efficient and effective communication across the brain’s various regions.

“Even a short period of Hsf1 overactivation during prenatal development causes critical neuronal migration deficiency. The severity of deficiency depends on the duration of Hsf1 overactivation,” Hashimoto-Torii says. “Expression patterns vary, however, across various tissues. Stochastic response within individual cells may be largely responsible for variability seen within tissue and organs.”

The research team found one bright spot: Cortical neurons that stalled due to lack of the microtubule-associated molecule Dcx were able to regain their ability to migrate properly when the gene was replenished after birth. A reduction in Hsf1 activity after birth, however, did not show the same ability to trigger the “reset” button on neural development.

“The finding suggests that genes other than microtubule-associated genes may play pivotal roles in ensuring that migrating neurons reach their assigned destinations in the brain at the right time – despite the added challenge of excessive Hsf1 activation,” according to Hashimoto-Torii.

Chinwe Unegbu

PDE-5 inhibitors for pediatric hypertension

Chinwe Unegbu

A study led by Chinwe Unegbu, M.D., indicates the benefits of PDE-5 inhibitors to treat pediatric pulmonary hypertension far outweigh potential harmful side effects.

Pulmonary hypertension (PH), when pressure in the blood vessels leading from the heart to the lungs is too high, is primarily a disease of adults: Patient registries suggest that the mean age of diagnosis is around age 50. However, more and more children are developing this condition, says Chinwe Unegbu, M.D., an assistant professor in the Division of Anesthesiology, Pain and Perioperative Medicine at Children’s National Health System.

Although adults with PH have several different effective treatments, Dr. Unegbu adds, children have few options. One of these is a class of medications known as phosphodiesterase type 5 (PDE-5) inhibitors, which act on molecular pathways that can open up constricted blood vessels. However, some studies have raised questions about the safety of this class of medications, particularly with long-term use of high dosages.

In a new study, Dr. Unegbu and colleagues performed a systematic review of available literature on this class of drugs evaluating their effectiveness and safety for pediatric patients. The review showed that like all medications, PDE-5 inhibitors have some risks. However, Dr. Unegbu says, the review showed that their benefits, including improved echocardiography measurements, cardiac catheterization parameters and oxygenation, far outweigh potential harmful side effects.

“Pediatricians across the nation view the rise in pediatric PH cases with growing concern because the disease can worsen, leading to right ventricular failure and death,” says Dr. Unegbu, lead author of the study. “PH can occur in newborns, infants and children who have a number of health conditions, including congenital heart disease, the most common birth defect among newborns. There are few available treatments for the growing population of children affected by this condition, so it is heartening that the evidence supports PDE-5 inhibitors for patients with PH.”

Patients with PH experience increased pressure in the pulmonary arteries, which carry blood from the heart to the lungs where it picks up oxygen that is ferried throughout the body. According to the National Institutes of Health, this leads patients to suffer from shortness of breath while doing routine tasks, chest pain and a racing heartbeat. Changes to the arteries make it progressively harder for the heart to pump blood to the lungs, which forces the heart to work even harder. Despite the heart muscle compensating by growing larger, less blood ultimately flows from the right to the left side of the heart which can compromise the kidney, liver and other organs, Dr. Unegbu says.

The study team included four researchers from Johns Hopkins University: Corina Noje, M.D., John D. Coulson, M.D., Jodi B. Segal, M.D., M.P.H., and study senior author Lewis Romer, M.D. The researchers scoured Medline, Embase, SCOPUS and the Cochrane Central Register of Controlled Trials, looking for studies that examined PDE-5 inhibitor use by pediatric patients with primary and secondary PH. Their goals included describing the nature and scale of the pediatric PH, assessing available pharmacologic therapies and conducting the systematic review of clinical studies of PDE-5 inhibitors, a mainstay of PH therapy.

They identified 1,270 studies. Twenty-one met the criteria to be included in the comprehensive review, including eight randomized controlled trials – the gold standard. The remaining 13 were  observational studies in children ranging in age from extremely preterm to adolescence.

“Although there is some risk associated with PDE-5 inhibitor use by pediatric patients with PH, overwhelmingly the data indicate the benefits of using this class of drugs far outweigh the risks. When we looked at specific clinical outcomes, we see definite improvement in a number of measures including oxygenation, hemodynamics and better clinical outcomes: The patients are doing better, feeling better and their exercise capacity rises,” Dr. Unegbu says.

Because of lingering concerns about increased mortality, they also looked at toxicity data associated with this class of drugs. “With the exception of a single trial, the remaining trials included in our review did not demonstrate increased mortality in patients placed on this class of medicines, which was reassuring to us,” she says. Side effects ranged from mild to moderate, such as flushing and headaches. “We can say with a good degree of confidence that providers should feel fairly comfortable prescribing PDE-5 inhibitors.”

Ideally, researchers would like to have access to patient-specific measures that are a good fit for neonates and infants. Unlike adults, infants’ exercise capacity cannot be measured by their ability to climb stairs or use a treadmill. Another limitation, the study authors note, is the dearth of adequately powered clinical trials conducted in kids.

“Most of the studies have been conducted in adults. However, this disease unfolds in a much different fashion in children compared with adults,” Dr. Unegbu says. “We are desperately in need of high-quality studies in the form of randomized controlled trials in pediatric patients and studies that examine the full range of formulations of this class of drugs.”

Dr. Keating and Abigail

Multidisciplinary approach to hydrocephalus care

Reflective of the myriad symptoms and complications that can accompany hydrocephalus, a multidisciplinary team at Children’s National works with patients and families for much of childhood.

The Doppler image on the oversized computer screen shows the path taken by blood as it flows through the newborn’s brain, with bright blue distinguishing blood moving through the middle cerebral artery toward the frontal lobe and bright red depicting blood coursing away. Pitch black zones indicate ventricles, cavities through which cerebrospinal fluid usually flows and where hydrocephalus can get its start.

The buildup of excess cerebrospinal fluid in the brain can begin in the womb and can be detected by fetal magnetic resonance imaging. Hydrocephalus also can crop up after birth due to trauma to the head, an infection, a brain tumor or bleeding in the brain, according to the National Institutes of Health. An estimated 1 to 2 per 1,000 newborns have hydrocephalus at birth.

When parents learn of the hydrocephalus diagnosis, their first question tends to be “Is my child going to be OK?” says Suresh Magge, M.D., a pediatric neurosurgeon at Children’s National Health System.

“We have a number of ways to treat hydrocephalus. It is one of the most common conditions that pediatric neurosurgeons treat,” Dr. Magge adds.

Unlike fluid build-up elsewhere in the body where there are escape routes, with hydrocephalus spinal fluid becomes trapped in the brain. To remove it, surgeons typically implant a flexible tube called a shunt that drains excess fluid into the abdomen, an interim stop before it is flushed away. Another surgical technique, called an endoscopic third ventriculostomy has the ability to drain excess fluid without inserting a shunt, but it only works for select types of hydrocephalus, Dr. Magge adds.

For the third year, Dr. Magge is helping to organize the Hydrocephalus Education Day on Feb. 25, a free event that offers parents an opportunity to learn more about the condition.

Reflective of the myriad symptoms and complications that can accompany hydrocephalus, such as epilepsy, cerebral palsy, cortical vision impairment and global delays, a multidisciplinary team at Children’s National works with patients and families for much of childhood.

Neuropsychologist Yael Granader, Ph.D., works with children ages 4 and older who have a variety of developmental and medical conditions. Granader is most likely to see children and adolescents with hydrocephalus once they become medically stable in order to assist in devising a plan for school support services and therapeutic interventions. Her assessments can last an entire day as she administers a variety of tasks that evaluate how the child thinks and learns, such as discerning patterns, assembling puzzles, defining words, and listening to and remembering information.

Neuropsychologists work with schools in order to help create the most successful academic environment for the child. For example, some children may struggle to visually track across a page accurately while reading; providing a bookmark to follow beneath the line is a helpful and simple accommodation to put in place. Support for physical limitations also are discussed with schools in order to incorporate adaptive physical education or to allow use of an elevator in school.

“Every child affected by hydrocephalus is so different. Every parent should know that their child can learn,” Granader says. “We’re going to find the best, most supportive environment for them. We are with them on their journey and, every few years, things will change. We want to be there to help with emerging concerns.”

Another team member, Justin Burton, M.D., a pediatric rehabilitation specialist, says rehabilitation medicine’s “piece of the puzzle is doing whatever I can to help the kids function better.” That means dressing, going to the bathroom, eating and walking independently. With babies who have stiff, tight muscles, that can mean helping them through stretches, braces and medicine management to move muscles smoothly in just the way their growing bodies want. Personalized care plans for toddlers can include maintaining a regular sleep-wake cycle, increasing attention span and strengthening such developmental skills as walking, running and climbing stairs. For kids 5 and older, the focus shifts more to academic readiness, since those youths’ “full-time job” is to become great students, Dr. Burton says.

The area of the hospital where children work on rehabilitation is an explosion of color and sounds, including oversized balance balls of varying dimensions in bright primary colors, portable basketball hoops with flexible rims at multiple heights, a set of foam stairs, parallel bars, a climbing device that looks like the entry to playground monkey bars and a chatterbox toy that lets a patient know when she has opened and closed the toy’s doors correctly.

“We end up taking care of these kids for years and years,” he adds. “I always love seeing the kids get back to walking and talking and getting back to school. If we can get them back out in the world and they’re doing things just like every other kid, that’s success.”

Meanwhile, Dr. Magge says research continues to expand the range of interventions and to improve outcomes for patients with hydrocephalus, including:

  • Fluid dynamics of cerebrospinal fluid
  • Optimal ways to drain excess fluid
  • Improving understanding of why shunts block
  • Definitively characterizing post-hemorrhagic ventricular dilation.

Unlike spina bifida, which sometimes can be corrected in utero at some health institutions, hydrocephalus cannot be corrected in the womb. “While we have come a long way in treating hydrocephalus, there is still a lot of work to be done. We continue to learn more about hydrocephalus with the aim of continually improving treatments,” Dr. Magge says.

During a recent office visit, 5-year-old Abagail’s head circumference had measured ¼ centimeter of growth, an encouraging trend, Robert Keating, M.D., Children’s Chief of Neurosurgery, tells the girl’s mother, Melissa J. Kopolow McCall. According to Kopolow McCall, who co-chairs the Hydrocephalus Association DC Community Network, it is “hugely” important that Children’s National infuses its clinical care with the latest research insights. “I have to have hope that she is not going to be facing a lifetime of brain surgery, and the research is what gives me the hope.”

pregnancy

New Children’s National and Inova collaboration

pregnancy

A new research collaboration will streamline completion of retrospective and prospective research studies, shedding light on myriad conditions that complicate pregnancies.

A new three-year, multi-million dollar research and education collaboration in maternal, fetal and neonatal medicine aims to improve the health of pregnant women and their children. The partnership between Children’s National Health System and Inova will yield a major, nationally competitive research and academic program in these areas that will leverage the strengths of both health care facilities and enhance the quality of care available for these vulnerable populations.

The collaboration will streamline completion of retrospective and prospective research studies, shedding light on a number of conditions that complicate pregnancies. It is one of several alliances between the two institutions aimed at improving the health and well-being of children in Northern Virginia and throughout the region.

“The Washington/Northern Virginia region has long had the capability to support a major, nationally competitive research and academic program in maternal and fetal medicine,” says Adre du Plessis, M.B.Ch.B., Director of the Fetal Medicine Institute at Children’s National and a co-Principal Investigator for this partnership. “The Children’s National/Inova maternal-fetal-neonatal research education program will fill this critical void.

“This new partnership will help to establish a closer joint education program between the two centers, working with the OB/Gyn residents at Inova and ensuring their involvement in Children’s National educational programs and weekly fetal case review meetings,” Dr. du Plessis adds.

Larry Maxwell, M.D., Chairman of Obstetrics and Gynecology at Inova Fairfax Medical Campus and a co-Principal Investigator for the collaboration, further emphasizes that “Inova’s experience in caring for women and children — combined with genomics- and proteomics-based research — will synergize with Children National’s leadership in neonatal pediatrics, placental biology and fetal magnetic resonance imaging (MRI) to create an unprecedented research consortium. This will set the stage for developing clinically actionable interventions for mothers and babies in metropolitan District of Columbia.”

Children’s National, ranked No. 3 nationally in neonatology, has expertise in pediatric neurology, fetal and neonatal neurology, fetal and pediatric cardiology, infectious diseases, genetics, neurodevelopment and dozens of additional pediatric medical subspecialties. Its clinicians are national leaders in next-generation imaging techniques, such as MRI. Eighteen specialties and 50 consultants evaluate more than 700 cases per year through its Fetal Medicine Institute. In mid-2016, Children’s National created a Congenital Zika Virus Program to serve as a dedicated resource for referring clinicians and pregnant women. The hospital performs deliveries in very high-risk, complex situations, but does not offer a routine labor and delivery program.

Inova Fairfax Medical Campus is home to both Inova Women’s Hospital and Inova Children’s Hospital. Inova Women’s Hospital is the region’s most comprehensive and highest-volume women’s hospital — delivering more than 10,000 babies in 2016. Inova Children’s Hospital serves as Northern Virginia’s children’s hospital —providing expert care in pediatric and fetal cardiology, cardiac surgery, genetics, complex general surgery, neurology, neurosurgery and other medical and surgical specialties. Its 108-bed Level IV neonatal intensive care unit is one of the largest and most comprehensive in the nation. Inova’s Translational Medicine Institute includes a genomics lab, as well as a research Institute focused on studies designed to build genetic models that help answer questions about individual disease. Each of these specialties is integrated into the Inova Fetal Care Center — which serves as a connection point between Inova Women’s and Children’s Hospitals. The Inova Fetal Care Center provides complex care coordination for women expecting infants with congenital anomalies or with other fetal concerns. Because Inova Women’s Hospital and Inova Children’s Hospital are co-located, women are able to deliver their babies in the same building where their children will receive care.

The research collaboration will support research assistants; tissue technicians; a placental biologist; as well as support for biomedical engineering, fetal-neonatal imaging, telemedicine, regulatory affairs and database management. The joint research projects that will take place under its auspices include:

  • Fetal growth restriction (FGR), which occurs when the failing placenta cannot support the developing fetus adequately. FGR is a major cause of stillbirth and death, and newborns who survive face numerous risks for multiple types of ailments throughout their lives. A planned study will use quantitative MRI to identify signs of abnormal brain development in pregnancies complicated by FGR.
  • Placental abnormalities, including placenta accreta. A planned study will combine quantitative MRI studies on the placenta during the third trimester and other points in time with formal histopathology to identify MRI signals of placenta health and disease.
  • Microcephaly, a condition that is characterized by babies having a much smaller head size than expected due to such factors as interrupted brain development or brain damage during pregnancy. While the global Zika virus epidemic has heightened awareness of severe microcephaly cases, dozens of pregnancies in the region in recent years have been complicated by the birth defect for reasons other than Zika infection. A planned study will examine the interplay between MRI within the womb and head circumference and weight at birth to examine whether brain volume at birth correlates with the baby’s developmental outcomes.

Setting a baseline for healthy brain development

Catherine Limperopoulos, Ph.D., and colleagues performed the largest magnetic resonance imaging study of normal fetal brains in the second and third trimesters of pregnancy.

Starting as a speck barely visible to the naked eye and ending the in utero phase of its journey at an average weight of 7.5 pounds, the growth of the human fetus is one of the most amazing events in biology. Of all the organs, the fetal brain undergoes one of the most rapid growth trajectories, expanding over 40 weeks from zero to 100 billion neurons — about as many brain cells as there are stars in the Milky Way Galaxy.

This exponential growth is part of what gives humans our unique abilities to use language or have abstract thoughts, among many other cognitive skills. It also leaves the brain extremely vulnerable should disruptions occur during fetal development. Any veering off the developmental plan can lead to a cascade of results that have long-lasting repercussions. For example, studies have shown that placental insufficiency, or the inability of the placenta to supply the fetus with oxygen and nutrients in utero, is associated with attention deficit hyperactivity disorder, autism, and schizophrenia.

Recent research has identified differences in the brains of people with these disorders compared with those without. Despite the almost certain start of these conditions within the womb, they have remained impossible to diagnose until children begin to show clinical symptoms. If only researchers could spot the beginnings of these problems early in development, says Children’s National Health System researcher Catherine Limperopoulos, Ph.D., they might someday be able to develop interventions that could turn the fetal brain back toward a healthy developmental trajectory.

“Conventional tools like ultrasound and magnetic resonance imaging (MRI) can identify structural brain abnormalities connected to these problems, but by the time these differences become apparent, the damage already has been done,” Limperopoulos says. “Our goal is to be able to pick up very early deviations from normal in the high-risk pregnancy before an injury to the fetus might become permanent.”

Before scientists can recognize abnormal, she adds, they first need to understand what normal looks like.

In a new study published in Cerebral Cortex, Limperopoulos and colleagues begin to tackle this question through the largest MRI study of normal fetal brains in the second and third trimesters of pregnancy. While other studies have attempted to track normal fetal brain growth, that research has not involved nearly as many subjects and typically relied on data collected when fetuses were referred for MRIs for a suspected problem. When the suspected abnormality was ruled out by the scan, these “quasi-controls” were considered “normal” — even though they may be at risk for problems later in life, Limperopoulos explains.

By contrast, the study she led recruited 166 healthy pregnant women from nearby low-risk obstetrics practices. Each woman had an unremarkable singleton pregnancy and ended up having a normal full-term delivery, with no evidence of problems affecting either the mother or fetus over the course of 40 weeks.

At least one time between 18 and 39 gestational weeks, the fetuses carried by these women underwent an MRI scan of their brains. The research team developed complex algorithms to account for movement (since neither the mothers nor their fetuses were sedated during scans) and to convert the two-dimensional images into three dimensions. They used the information from these scans to measure the increasing volumes of the cerebellum, an area of the brain connected to motor control and known to mediate cognitive skills; as well as regions of the cerebrum, the bulk of the brain, that is pivotal for movement, sensory processing, olfaction, language, and learning and memory.

Their results in uncomplicated, full-term pregnancies show that over 21 weeks in the second half of pregnancy, the cerebellum undergoes an astounding 34-fold increase in size. In the cerebrum, the fetal white matter, which connects various brain regions, grows 22-fold. The cortical gray matter, key to many of cerebrum’s functions, grows 21-fold. And the deep subcortical structures (thalamus and basal ganglia), important for relaying sensory information and coordination of movement and behavior, grow 10-fold. Additional examination showed that the left hemisphere has a larger volume than the right hemisphere early in development, but sizes of the left and right brain halves were equal by birth.

By developing similar datasets on high-risk pregnancies or births—for example, those in which fetuses are diagnosed with a problem in utero, mothers experience a significant health problem during pregnancy, babies are born prematurely, or fetuses have a sibling diagnosed with a health problem with genetic risk, such as autism—Limperopoulos says that researchers might be able to spot differences during gestation and post-natal development that lead to conditions such as schizophrenia, attention deficit hyperactivity disorder and autism spectrum disorder.

Eventually, researchers may be able to develop fixes so that babies grow up without life-long developmental issues.

“Understanding ‘normal’ is really opening up opportunities for us to begin to precisely pinpoint when things start to veer off track,” Limperopolous says. “Once we do that, opportunities that have been inaccessible will start to present themselves.”

Altered blood flow may contribute to preemie brain injuries

A Children’s National research team for the first time mapped abnormalities in blood flow that may contribute to brain injury suffered by preterm infants.

Advanced noninvasive imaging permitted Children’s National Health System researchers to measure the lasting impact of abnormalities in blood flow on the immature brains of premature babies. Blood flow to the brain, or perfusion, has been studied previously to understand its role in other health conditions, but this is the first time a research team has mapped how these changes may contribute to brain injury suffered by babies born before 32 weeks’ gestation.

Preterm birth is a major risk factor for brain injury. The prospective study examined infants weighing less than 1,500 grams who were born prior to 32 gestational weeks.

Of 78 infants studied, 47 had structural brain injuries categorized as either mild or moderate to severe, and 31 had no brain injury. While global cerebral blood flow decreased with advancing postnatal age, the blood flow decreased more significantly among preterm infants with brain injury, says Eman S. Mahdi, M.D., M.B.Ch.B. Dr. Mahdi is a pediatric radiology fellow at Children’s National and lead author of the abstract.

“In addition to differences in global brain blood flow, we saw a marked decrease in regional blood flow to the thalamus and the pons, regions known to be metabolically active during this time,” Dr. Mahdi says. The thalamus helps to process information from the senses and relays it elsewhere within the brain. Located at the base of the brain, the pons is part of the central nervous system and also is a critical relay of information between the cerebrum and cerebellum. “These regional variations in blood flow reflect vulnerability of the cerebral-cerebellar circuitry,” she adds.

The Radiological Society of North America (RSNA) recognized Dr. Mahdi with its Trainee Research Prize. She presented the work, “Cerebral Perfusion Is Perturbed by Preterm Birth and Brain Injury,” during the RSNA Scientific Assembly and Annual Meeting, held from Nov. 27 to Dec. 2.

The findings point to the need for additional research to explore how cerebral blood flow trends evolve as preemies grow older and whether abnormal blood flow is linked to differences in health outcomes. In addition, the technique used by the research team, arterial spin labeling perfusion imaging – a type of magnetic resonance imaging – represents a useful and non-invasive technology for identifying early cerebral perfusion abnormalities in preterm infants, says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National and abstract senior author.

Doctors working together to find treatments for autoimmune encephalitis

Children’s and Regeneron partner in exome sequencing study

Children’s National, in partnership with the Regeneron Genetics Center (RGC, a subsidiary of Regeneron Pharmaceuticals, Inc.), has announced the launch of a major three-year research study that will examine the links between undiagnosed disease and an individual’s genetic profile.

The program, directed by Children’s National Geneticist Carlos Ferreira Lopez, M.D., and coordinated by Genetic Counselor Lindsay Kehoe, hopes to include as many as 3,000 patients in its initial year and even greater numbers in the following two years.

During the course of the study, RGC will conduct whole exome sequencing (WES) to examine the entire protein-coding DNA in a patient’s genome. Children’s National geneticists will analyze and screen for certain findings that are known to be potentially causative or diagnostic of disease. Children’s National scientists and providers will confirm preliminary research findings in a lab certified for Clinical Laboratory Improvement Amendments (CLIA), per federal standards for clinical testing, and refer any confirmatory CLIA-certified cases to appropriate clinicians at Children’s National for further care.

According to Marshall Summar, M.D., Chief of Genetics and Metabolism at Children’s National, the WES study could finally provide patients and their families with the medical answers they have been looking for, allowing for treatment appropriate to their specific genetic condition.

Because pediatric diseases can often elude diagnosis, they can pose a number of detrimental effects to patients and their families, including treatment delays, multiple time- and cost-intensive tests, and stress from lingering uncertainty regarding the illness. With this genomic data, Regeneron will be able to utilize findings to continue its efforts to improve drug development.

Since its inception in 2014, the RGC has strategically partnered with leading medical institutions to utilize human genetics data to speed the development and discovery of new and improved therapies for patients in need.

Premature birth may alter critical cerebellar development linked to learning and language

Diffusion tensor imaging teases out subtle injury to cerebral and cerebellar white matter that is not evident with conventional MRI, allowing researchers to quantify brain tissue microstructure and classify white matter integrity.

Diffusion tensor imaging teases out subtle injury to cerebral and cerebellar white matter that is not evident with conventional MRI, allowing researchers to quantify brain tissue microstructure and classify white matter integrity.

Premature birth can interrupt a key period of brain development that occurs in the third trimester, which has the potential to impact a child’s long-term learning, language, and social skills. A recent case-control study published in The Journal of Pediatrics applied diffusion tensor magnetic resonance imaging (DTI) to zoom in on the microstructures comprising the critical cerebellar neural networks related to learning and language, and found significant differences between preterm and full-term newborns.

“The third trimester, during which many premature births occur, is typically when the developing cerebellum undergoes its most dramatic period of growth. Normally, the cerebellar white matter tracts that connect to the deep nuclei are rich in pathways where nerve fibers cross. Those connections permit information to flow from one part of the brain to another. It is possible that premature birth leads to aberrant development of these critical neural networks,” says Catherine Limperopoulos, Ph.D., director of the Developing Brain Research Laboratory at Children’s National Health System and senior study author.

One in 10 American babies is born prematurely. The brain injury that infants born prematurely experience is associated with a range of neurodevelopmental disabilities, including some whose influence isn’t apparent until years later, when the children begin school. Nearly half of extremely preterm infants go on to experience long-term learning, social, and behavioral impairments.

While conventional magnetic resonance imaging (MRI) can detect many brain abnormalities in newborns, a newer technique called DTI can tease out even subtle injury to cerebral and cerebellar white matter that is not evident with conventional MRI. White matter contains axons, which are nerve fibers that transmit messages. With DTI, researchers can quantify brain tissue microstructure and describe the integrity of white matter.

The research team compared imaging from 73 premature infants born before 32 weeks gestation who weighed less than 1,500 grams with 73 healthy newborns born to mothers who delivered at full term after 37 weeks. After the newborns had been fed, swaddled, and fitted with double ear protection, the imaging was performed as they slept. Nurses monitored their heart rates and oxygen saturation. Their brain abnormalities were scored as normal, mild, moderate, or severe.

All of the full-term newborns had normal brain MRIs as did 44 (60.3 percent) of the preemies.

The preemies had significantly higher fractional anisotropy in the cerebellum, the part of the brain that processes incoming information from elsewhere in the brain, permitting coordinated movement as well as modulating learning, language, and social skills. Alterations in cerebellar microarchitecture was associated with markers for illness severe enough to require surgery – such as correcting abnormal blood flow caused by the failure of the ductus arteriosus to close after birth and to remedy a bowel disease known as necrotizing enterocolitis. The risk factors also are associated with compromised cardiorespiratory function and low Apgar score at five minutes, Limperopoulos and co-authors write. The Apgar score is a quick way to gauge, one minute after birth, how well the newborn withstood the rigors of childbirth. It is repeated at five minutes to describe how the newborn is faring outside of the womb.

“In previous studies, we and others have associated cerebellar structural injury in preterm infants with long-term motor, cognitive, and socio-affective impairments. This is one of the first studies to provide a detailed report about these unexpected alterations in cerebellar microstructural organization,” she adds. “We postulate that the combination of premature birth and early exposure of the immature developing cerebellum to the extrauterine environment results in disturbed micro-organization.”

Additional research is warranted in larger groups of patients as well as long-term follow up of this cohort of newborns to determine whether this microstructural disorganization predicts long-term social, behavioral, and learning impairments.

“A large number of these prematurely born newborns had MRI readings in the normal range. Yet, we know that these children are uniquely at risk for developing neurodevelopmental disabilities later in life. With additional study, we hope to identify interventions that could lower those risks,” Limperopoulos says.

Related resources: The Journal of Pediatrics editorial

Fetal Cardiac Health

Managing transposition of the great arteries in the womb

Fetal Cardiac Health

Monitoring and managing fetuses’ heart health in the womb can greatly improve their chances of living long and productive lives

Over the 22 years that Mary T. Donofrio, M.D., has been practicing fetal cardiology, the field has changed radically. The goal once had been simply to offer parents an accurate diagnosis and prepare them for sometimes devastating outcomes. Now, Dr. Donofrio, who directs the Fetal Heart Program and Critical Care Delivery Program at Children’s National Health System, says specialists can follow fetuses throughout the pregnancy and manage many conditions in the womb, greatly improving their chances of living long and productive lives.

Case in point: Transposition of the great arteries, a congenital defect characterized by reversal of the heart’s two main arteries—the aorta, which distributes oxygenated blood throughout the body, and the pulmonary artery, which carries deoxygenated blood from the heart to the lungs. The single abnormality means that the oxygenated “red” blood flows back to the lungs while deoxygenated “blue” blood flows out to the body.

After birth, when the cord is clamped and the connection to the placenta severed, the baby’s cardiovascular system must adjust. If the fetal connections between the two sides of the heart no longer remain, the brain and other organs in infants with this defect are severely deprived of oxygen. The condition may be fatal if something is not done immediately to reopen the fetal connections to stabilize the circulation before surgery can be done. But if the fetal cardiologist can keep tabs on what’s happening to the heart over time and prepare a specialty team of cardiologists to treat the problem immediately after birth, chances of survival are significantly improved.

More than a decade ago, as a young attending physician, Dr. Donofrio witnessed a case that has stuck with her to this day. The baby’s diagnosis of transposition of the great arteries was not made until shortly before birth. In addition, the two fetal blood flow connections that allow blood to circulate had closed, causing severe heart failure. Although the care team performed an emergency delivery and immediate cardiac procedure, including initiation of a heart-lung machine in the delivery room to try to stabilize the circulation, the baby ultimately died due to complications from a very low oxygen level. “I always wonder what happened,” Dr. Donofrio says. “Was the baby’s heart always that bad and nobody noticed it, or did it change over time?”

In a paper published recently in the Journal of Neonatal-Perinatal Medicine, she and colleagues illustrate the dramatic transformation in care that has taken place in the 14 years since this unforgettable case. The new publication describes the case of a different fetus diagnosed at 22 weeks gestation with transposition of the great arteries in 2015 at Children’s National. Unlike many congenital heart disorders, the heart’s four chambers appear misleadingly normal at the typical mid-pregnancy ultrasound. Despite the challenging diagnosis for many obstetricians, this fetus’ heart condition was recognized early by looking at the arteries leaving the heart in addition to the chambers.

While such a defect is fatal if left untreated, Dr. Donofrio explains there are two pathways that can allow the blood to get to where it needs to go such that the circulation is stabilized and the damage mitigated. One is the fetal blood vessel known as the ductus arteriosus that typically stays open for a day or two after birth. The second is an opening between the heart’s two upper chambers, known as the foramen ovale, which usually closes upon delivery. By keeping those two pathways open, blood can cross from one side of the heart to the other, buying time in the delivery room so that babies can be stabilized before they receive surgery to permanently move the arteries back to their normal position.

In the 2015 case, Dr. Donofrio and colleagues had the chance to monitor the fetus and the fetal heart at follow-up appointments every four weeks after diagnosis. What they saw completely changed the course of their treatment plan and likely saved the baby’s life. With each ultrasound, they saw that the ductus arteriosus and the foramen ovale—the critical connections needed for survival—were gradually closing.

Dr. Donofrio noted at the fetal evaluation at 38 weeks that the structures had closed, and the heart was showing signs that it was not functioning well.  She and her team realized that the only way to save this baby was to deliver earlier than planned and to have cardiac specialists standing by ready to perform a life-saving procedure to open the connections right after the baby was separated from the placenta. The baby was delivered by Cesarean section in the cardiac operating room at Children’s. The cardiac intervention team immediately created a hole where the foramen ovale should have been by using a balloon to open the tissue that had closed. The care team also administered a prostaglandin infusion, a drug that can keep the ductus arteriosis open. This time, however, the medicine did not work. The baby was stabilized with several cardiac medications and, with little time to spare, the cardiac surgeons operated on the one-day-old baby to switch his great arteries back to the normal position, saving his life.

The baby is now 1-year-old, Dr. Donofrio says, and is healthy—a scenario that likely wouldn’t have happened had the fetal team not made the diagnosis and continually monitored the condition in the womb.

“I remember back to that first case when we were really scrambling to do everything we could at the last minute because we didn’t have the information we needed until the very end,” Dr. Donofrio says. “Now, we can spot problems early and do something about it. For me, that’s amazing. We’re making a difference, and that’s a really great thing.”

Every day fetuses remain in utero critical to preserving normal brain development

preemieimage

If it does not jeopardize the health of the pregnant mother or her fetus, pregnancies should be carried as close to full term as possible to avoid vulnerable preemies experiencing a delay in brain development, study results published October 28 in Pediatrics indicate.

Some 15 million infants around the world – and 1 in 10 American babies – are born prematurely. While researchers have known that preemies’ brain growth is disturbed when compared with infants born at full term, it remained unclear when preemies’ brain development begins to veer off course and how that impairment evolves over time, says Catherine Limperopoulos, Ph.D., Director of the Developing Brain Research Laboratory at Children’s National Health System and senior study author.

A look at the research

In order to shine a spotlight on this critical phase of fetal brain development, Limperopoulos and colleagues studied 75 preterm infants born prior to the 32th gestational week who weighed less than 1,500 grams who had no evidence of structural brain injury. These preemies were matched with 130 fetuses between 27 to 39 weeks gestational age.

The healthy fetal counterparts are part of a growing database that the Children’s National Developing Brain Research Laboratory has assembled. The research lab uses three-dimensional magnetic resonance imaging to carefully record week-by-week development of the normal in utero fetal brains as well as week-by-week characterizations of specific regions of the fetal brain.

The availability of time-lapsed images of normally developing brains offers a chance to reframe research questions in order to identify approaches to prevent injuries to the fetal brain, Limperopoulos says.

“Up until now, we have been focused on examining what is it about being born too early? What is it about those first few hours of life that leaves preemies more vulnerable to brain injury?” she says. “What is really unique about these study results is for the very first time we have an opportunity to better understand the ways in which we care for preemies throughout their hospitalization that optimize brain development and place more emphasis those activities.”

When the research team compared third-trimester brain volumes, preemies showed lower volumes in the cerebrum, cerebellum, brainstem, and intracranial cavity. The cerebrum is the largest part of the brain and controls speech, thoughts, emotions, learning, as well as muscle function. The cerebellum plays a role in learning and social-behavioral functions as well as complex motor functions; it also controls the balance needed to stand up and to walk. The brainstem is like a router, ferrying information between the brain, the cerebellum, and the spinal cord.

“What this study shows us is that every day and every week of in utero development is critical. If at all possible, we need to keep fetuses in utero to protect them from the hazards that can occur in the extra uterine environment,” she says.

New program provides science-driven answers about zika virus’s impact on pregnancies

Drs. DeBiasi and du Plessis

Each week, as temperatures rise, the likelihood increases that the United States will experience domestic Zika virus transmission. Indeed, such domestic Zika transmission already is occurring in Puerto Rico and the U.S. Virgin Islands. The Children’s National Health System Fetal Medicine Institute and Division of Pediatric Infectious Disease announced the formation of a Congenital Zika Virus Program to serve as a dedicated resource for referring clinicians and for pregnant women to receive counseling and science-driven answers about the impact of the Zika virus on their pregnancies.

Over years, Children’s National has invested in equipment and highly trained personnel, building expertise in infectious diseases, pediatric neurology, pediatric cardiology, genetics, neurodevelopment, and other specialties. Children’s clinicians are recognized as national leaders in next-generation imaging techniques, such as fetal MRI, and a variety of divisions work together to offer multidisciplinary support and coordinated care to infants born with special needs. As the nation prepares for the Zika virus, Children’s National is facilitating the multi-step process of blood testing, helping to ensure timely and precise information. Children’s National specialists are able to guide Zika-affected pregnancies through the fetal period and can oversee the care of Zika-affected infants after delivery. Care and clinical support is provided by a multidisciplinary team of pediatric neurologists, physical therapists, infectious disease experts, and neurodevelopmental physicians.