As the storm hit, and the toll of its devastation became clear, Nomura realized she was uniquely positioned to investigate a more specific question: How would the stress of the natural disaster affect not only the pregnant women, but their children who were exposed to it while in utero?
The newest data from Nomura’s years-long “Stress in Pregnancy” study, co-written by Jeffrey Newcorn, a professor of psychiatry and pediatrics and director of the ADHD and learning disorders division at Icahn School of Medicine at Mount Sinai, left her stunned, Nomura said.
The study, published in the Journal of Child Psychology and Psychiatry, found that children who were exposed to Sandy, a superstorm, while in utero had substantially increased risks for depression, anxiety and attention deficit and disruptive behavior disorders. The symptoms of these disorders presented when the children were preschool-age.
The specific behavioral patterns varied by the children’s sex, the study found, with girls more likely to experience anxiety and depression, while attention deficit and disruptive behaviors were more prevalent among boys.
Among the most striking findings: Girls who were exposed to Sandy in utero experienced a 20-fold increase of generalized anxiety disorder and a 30-fold increase of depressive disorder, compared with girls who were not exposed to the storm. Among boys who were in utero during Sandy, researchers found that they were at an over 60-fold increased risk to develop ADHD, a 20-fold increased risk to develop conduct disorder and a 15-fold increased risk to develop oppositional defiant disorder.
“We know for sure that in utero exposure to stress during pregnancy affects the mental health development of the child,” Nomura said. “We know the perinatal period is a very vulnerable time. What we didn’t know, though, is the magnitude of that impact, and I was really surprised that our sample had such a high prevalence of these disorders. I did not expect this to be so clear-cut.”
The implications of the study, the researchers noted, are particularly significant in a world that is increasingly altered by a changing climate, with the effects of natural disasters disproportionately impacting already vulnerable and marginalized communities of color.
The study followed 163 preschool-age children from diverse racial and economic backgrounds, 40.5 percent of whom were exposed to Sandy in utero and 59.5 percent of whom were not, either having already been born before the storm, or conceived after it had passed. The research team conducted interviews with the children’s parents and monitored the health of the children to track both normal and abnormal development, Nomura said.
The mothers involved in the study were affected by the storm in a multitude of ways, Nomura explained: One told her that she had been trapped in an elevator for hours, unable to get help. Others were left without running water, or without access to diapers or formula for their children. Some lost their jobs, their means of transportation or their homes. These stresses are not unusual following a natural disaster, Nomura said, “but the difference is that these people are pregnant, so whatever stress they are dealing with, it goes directly through the placenta.” Many of these women, Nomura noted, exhibited symptoms of post-traumatic stress disorder as a result of their experiences.
The study represents a novel addition to the substantial body of research surrounding the impact of maternal prenatal stress on the developing fetal brain, said Jill Goldstein, professor of psychiatry and medicine at Harvard Medical School and founder and executive director of the Innovation Center on Sex Differences in Medicine at Massachusetts General Hospital, in an email to The Washington Post.
“The study by Nomura and colleagues reports another example of how environmental occurrences, when extreme and sustained, have substantial impact on population health, and for those women who are pregnant, can impact the developing fetus,” Goldstein said. “Depending on the timing of exposure, it can have differential impact on the male and female brain … The authors use a natural experiment in a novel way to study [Sandy] and its impact on offspring psychiatric outcomes that differs by sex.”
The study, Goldstein said, underscores the fact that “maternal health during pregnancy leads critically to population health — a theme that is quite relevant during these current political storms around women’s health.”
Previous studies have shown that high levels of stress during pregnancy have been linked to outcomes including low birth weight, premature birth and an elevated risk of a multitude of physiological, psychological and behavioral disorders.
Newcorn noted that the new data “extends the work that’s been done in this area, it takes it a little farther in terms of psychiatric disorders,” he said. “And of course, it puts it in relationship to the major environmental stress of a natural disaster.”
The team is hoping to continue their work, he added, and follow the children as they age.
“We have to know what’s going to happen to those children when they hit adolescence,” Nomura said. “We are going to have to follow those kids to see how the manifestation of these disorders is going to present.”
Newcorn said it is also important to explore exactly how maternal stress is causing these outcomes for children to help mitigate the risk. While there is clearly a relationship between environmental and genetic factors at play, he said, there are still many unanswered questions.
“We’d especially like to be able to do more research to find out why this actually happened,” he said. “What were the exact mechanisms that brought this about?”
Having a better understanding of this will be essential to helping society navigate a rapidly changing environment, he notes, where avoiding exposure to natural disasters while pregnant will often not be possible. In the meantime, the researchers say, parents, educators and pediatricians should be aware that children who were exposed to the stress of a natural disaster while in utero are at heightened risk for psychiatric disorder, even when they are very young.
“There is a general myth that makes people think that children don’t have psychiatric disorders at very early ages, but that’s not true,” Nomura said. “Everyone knows early intervention is most effective, but you can’t have early intervention without having an actual diagnosis.”
Ultimately, she said, she wants their work to help prepare future generations to better navigate a changing world.
“Because of global warming, natural disasters are going to continue to happen with greater frequency and greater magnitude,” she says. She hopes their research will “help guide what is going to happen, so that we will be able to come up with better planning, better intervention, better infrastructure. People are not going to stop getting pregnant just because natural disasters are continuing to happen, so we have to find a way to make it easier for society to have better-functioning children in the future.”