In 2012, a rare weather event occurred off the Eastern Coast of the US. A hurricane, a cold air mass, and the gravitational pull of a full moon came together to create what meteorologists would later describe as a “perfect storm.”

The resulting tropical cyclone, Superstorm Sandy, made landfall in New Jersey, unleashing catastrophic flooding and storm surges across the region. Rising sea levels driven by climate change amplified the devastation, exposing an estimated additional 71,000 people to the storm’s impact.

Among those in Sandy’s path was Yoko Nomura, PhD, a professor of psychology at City University of New York (CUNY) Queens College in New York City. When Sandy came ashore, Nomura was leading a longitudinal analysis of the effects of prenatal stress on fetal development. Because many of the pregnant people in her study lived through the storm and its aftermath, Sandy became an unplanned natural experiment in how extreme weather and climate-related disasters affect the developing brain in utero.

“I already had an infrastructure in place, and I took advantage of the unfortunate devastation caused by a weather-related disaster as a natural experiment in the human population. A gold standard of randomization is not possible in humans, and this provided me with unparalleled opportunities for a quasi-experiment of stress exposure in utero,” Nomura told Medscape Medical News.

Thirteen years on, these children show neurologic and psychiatric differences compared with peers whose mothers weren’t affected by Sandy. Nomura’s early findings suggest the differences may be related to in utero exposure to maternal stress caused by the superstorm. There is also evidence that additional prenatal exposure to extreme heat amplified these effects.

As the Earth’s climate continues to change and extreme weather events like Sandy and high temperatures become more common, Nomura and other researchers warn these children are unlikely to be the last to show neurodevelopmental effects related to climate change.

The Children of Superstorm Sandy

Climate change can increase the frequency, intensity, and effects of extreme weather events, which research suggests can lead to psychological and physiologic stress in pregnant individuals — and affect fetal brain development.

A 2024 systematic review that included 1.3 million mother-child dyads showed prenatal exposure to natural disasters had negative effects on cognitive and language development, motor skills, sleep and attention, autism or autism-like features, and various psychiatric comorbidities.

These findings align with broader conclusions from a 2023 report from the American Psychological Association, which noted that environmental and climate stressors during pregnancy can put children “at risk for a range of social, cognitive, psychiatric, and behavioral dysfunctions.” 

“If you’re exposed to these climate-related effects in the prenatal period, they’re going to have an outsized negative effect because the brain is still developing. During that time of development, it’s very, very sensitive to outside climate-related exposures” like temperature and wildfire smoke, Lindsey Burghardt, MD, MPH, FAAP, chief science officer at the Center on the Developing Child and founding director of the Early Childhood Scientific Council on Equity and the Environment at Harvard University in Cambridge, Massachusetts, told Medscape Medical News.

Superstorm Sandy provided a vivid example of prenatal stress effects in action. Early results from Nomura’s study published this year showed that on MRI, the volume of gray matter in the basal ganglia — which are involved in motor control, emotional regulation, and cognitive function — was “discernibly larger” in children exposed to Sandy before birth than in unexposed children.

Exposure to Sandy was associated with a 2-6% increase in brain volume in the putamen and pallidum bilaterally and right caudate. Increased volumes in these regions have previously been linked to high-functioning autism spectrum disorder, depressive symptoms and attention deficit/hyperactivity disorder (ADHD) risk, respectively, the investigators noted.

Nomura’s findings also suggest that the effects on the brain were amplified in children in the Sandy cohort whose mothers were also exposed to extreme heat while pregnant. Specifically, children exposed to both stressors showed a smaller left nucleus accumbens and increased left pallidum volume.

“We think that Sandy’s exposure alone poses a pretty great threat and stress to the mother when she’s pregnant, and that may lead to those changes to the brain. And we think that when that’s compounded with another ongoing environmental stressor, that amplifies those effects and leads to more pronounced differences,” study co-investigator, Donato DeIngeniis, research lead in neuroimaging at the Stress in Pregnancy study at Queens College and PhD student at the CUNY Graduate Center, told Medscape Medical News.

In a 2022 study, Nomura’s team found preschool children from the Sandy cohort had a fivefold increased risk for anxiety and a threefold increased risk for attention-deficit/disruptive behavioral disorders compared with control individuals. There were key differences by biological sex: a higher risk for anxiety and depressive disorders among girls and an increased risk for disruptive behavioral and ADHD disorders among boys.

DeIngeniis emphasized that the goal is not to alarm or blame women for experiencing stress. “We want to recognize that these are normal and expected experiences but trying to increase awareness and preparedness for the future is really what we’re after.”

‘Thermal Discomfort’

Although the effects of prenatal maternal stress on neurodevelopment are well-documented, the precise mechanisms are unclear, Vivette Glover, PhD, professor of perinatal psychobiology at Imperial College London in London, England, told Medscape Medical News.

Stress may activate the hypothalamic pituitary adrenal (HPA) axis, increasing maternal cortisol and reducing the placenta’s ability to regulate the enzyme that metabolizes it.

Cortisol is key to normal fetal development but Glover’s research showed that increased cortisol exposure in utero, measured by amniotic fluid concentration, was linked to impaired infant cognitive ability. However, she also found this association can be mitigated by secure early child-mother attachment.

Genetic vulnerability can also influence a child’s risk of developing cognitive, emotional, or behavioral problems later in life, Glover said. However, she cautioned that none of these outcomes are inevitable, they only indicate increased risk.

Still, emerging data now show how specific environmental stressors — such as extreme temperatures — may influence brain development.

A 2024 European study that included MRI brain scans of 2681 children aged 9-12 years showed that exposure to regional extremes of heat and cold during pregnancy and infancy was associated with higher global mean diffusivity values, even after adjusting for multiple confounders.

Abnormal mean diffusivity has been linked to worse cognitive performance or internalizing and externalizing behaviors in later in life , Mònica Guxens, MD, MPH, PhD, research professor and head of the Brain Child Lab at Barcelona Institute for Global Health in Barcelona, Spain, told Medscape Medical News.

“We are hypothesizing that the development is not as we would expect for this age,” Guxens said, noting in her paper that the HPA axis and increased cortisol may be an underlying mechanism, which “thermal discomfort” can activate. Thermal discomfort is the sense of being uncomfortably hot or cold in a given environment, which can activate physiologic stress pathways and elevate cortisol.

A different birth cohort study focusing on heat wave exposure during early and late pregnancy showed an association with an increased risk for neurodevelopmental delay.

A potential outcome of extreme heat that flies under the radar is an increased risk for premature birth, Burghardt said.

“We all know many premature babies who are thriving and doing very well. But as a group [they] are at heightened risk for a range of different neurodevelopmental outcomes; challenges with learning, attention, memory, and behavioral changes,” she said.

Burghardt also pointed to wildfires as another overlooked area of climate change affecting neurodevelopment. The blood-brain barrier isn't fully developed at birth, which Burghardt said could allow particulate matter from wildfires like PM 2.5 to cross into the brain during pregnancy or in a child's early months.

“Once they’re there, they don’t leave. There’s documented links between exposure to PM 2.5 and a range of neurodevelopmental effects, ADHD. There’s links to heightened rates of autism to impaired school performance,” she said.

Time to Talk to Patients About Climate Change?

Given the data on the effects of climate change on early development, it may be time to incorporate the topic into patient care, the experts said.

“Perhaps in the future, pediatricians and child psychiatrists will regularly add prenatal exposures to disasters to other commonly screened-for hazards such as low birth weight, pregnancy-harming (teratogenic) medication exposure, and substance use,” Jacob Lee, MD, child and adolescent psychiatrist based in Honolulu, Hawaii, and chair of the American Psychiatric Association’s Committee on Climate Change and Mental Health, told Medscape Medical News.

He suggested psychiatrists introduce climate change discussions into their practice by asking transnational migrant patients about the factors that led their family to move and discussing patient’s attitudes about the current changes to the natural world.

In a recent interview with the American Psychiatric Association, Lee said his committee is working to add a Z diagnostic code to describe climate-related distress to monitor the growing prevalence of related conditions.

Evidence suggests that interventions like psychotherapy, meditation, and even music might help to alleviate prenatal stress, Glover said.

Clinicians can help patients understand available resources including local cooling stations, planning for extreme weather events and tools to monitor air quality, Burghardt said. Of key importance is “making the connection that climate change is a children’s health and brain development issue, and it's one that we can do something about,” she said.

Nomura’s team continues to follow the Sandy kids, who are now entering puberty, to evaluate their longitudinal development. Their brain imaging parameters are modeling the Adolescent Brain Cognitive Development Study, the largest long-term study of brain development and child health in the US.

Beyond brain imaging, they are also assessing other data including hormonal, environmental, and genetic influences to paint a full picture of the cohort’s developmental trajectory. The hope is to identify key changes or targets for early intervention to reduce the risk for certain neuropsychiatric disorders, Nomura said.

“People don’t understand the long-term consequences of exposure to natural disaster-related stress,” she said. She added that it’s essential to share clear information so that vulnerable groups — including older adults, young children, and pregnant women — can make informed decisions.

Burghardt, Nomura, DeIngeniis, Glover, and Lee reported no disclosures.