How Pregnant Women's Exposure To Climate Change May Affect Babies Brains

Climate disasters are known for damaging homes, disrupting power and displacing residents. But even after the lights come back on and people return to their homes, their effects can linger - including in the brains of children born afterwards, a new study suggests. 

Climate stressors, and the effect they have on pregnant people, appear to affect the brain development of their babies, according to the study published in PLOS One on Wednesday, which relied on brain imaging conducted years after 2012's Superstorm Sandy hit the New York City metro area. 

The study evaluated a sample of 34 children, 11 whose parents were pregnant during Superstorm Sandy. By the time of assessment, the kids were roughly eight years old. Those who had been exposed to Sandy in utero had a significant enlargement in a part of the brain known as the basal ganglia. Parts of the basal ganglia were as much as 6% larger than in unexposed children, a change that could have negative implications for the children's behavior. The parents living through the disruptions from a storm that displaced more than 23,000 people and suspended electric services in the area for days to weeks may have affected their offspring's neurodevelopment, the researchers say.

The findings signal how new generations of children may be marked by climate crises that occur before they were born, and speak to a need to better evaluate and educate pregnant people about climate risks, the researchers say.  They contribute to a growing consensus about pregnant people's vulnerability to climate change, with extreme heat, air pollution and natural disasters posing risks like preterm births. 

"This is something which people who are going to get pregnant should know and be prepared," says Yoko Nomura, an author of the PLOS One research and a professor at Queens College at the City University of New York. "Society as a whole has to have a strategy to protect those pregnant people."

Climate stress and the brain

Non-climate-related stress can affect pregnancies and influence fetal brain development. But studies typically haven't examined how natural disasters may work in the same way. Project Ice Storm, a project examining the aftermath of a devastating 1998 storm in Canada, found that stress had an effect on everything from kids' temperament to their IQ. 

Superstorm Sandy, which hit New York and New Jersey in October 2012, devastated coastal areas, leading to around 120 deaths and billions in damages. Queens College, in Flushing, New York, served as a shelter. Nomura, who was already on the faculty there at the time, observed how distressed storm evacuees in the on-campus gym were. Many of them were pregnant, and facing stressors like losing power and being displaced from their homes. That inspired Nomura to look into how the experience might affect their unborn babies. 

While the team hasn't yet determined how the changes they observed in the basal ganglia may affect participating children in the day-to-day, that part of the brain is involved in functions including emotional regulation. Other studies have linked the basal ganglia to conditions like depression and autism. 

"We do think that those changes we're seeing could lead to negative outcomes for the children's behavior," says Donato DeIngeniis, the study's lead author and a doctoral student in clinical neuropsychology at the CUNY Graduate Center.

For a subset of seven children whose parents had been exposed to Sandy and separately, over the course of their parent's pregnancy, extreme heat, the brain differences were more pronounced. Researchers observed that one portion of the basal ganglia  was enlarged while another was reduced. "That might mean one area is impaired, which might lead the other to have to work harder to compensate," DeIngeniis says, which is common in the brain in instances of brain damage or injury. 

The cohort of children examined in the study is small, reflecting the cost of brain imaging and the fact that the study's recruitment was interrupted by the Covid-19 crisis. Even after recruitment resumed in 2021, participants were reluctant to visit for in-person imaging.

Burcin Ikiz, chair of the Neuro Climate Working Group, part of Columbia University's Global Consortium on Climate and Health Education, calls the study "small but mighty."

It's increasingly important to understand how different climate stressors may together affect human health, she says. For instance, children in New Delhi are experiencing both air pollution and extreme heat. "And this is one of the first studies - that's why it's a trailblazing study - that looks at these joint things," she says.

But she added that additional work still needs to be done to address limitations of the study such as the small sample size, and to examine the effect of heat more in depth.  While the researchers used statistical methods to ensure the accuracy of their findings, it's still possible that other factors could explain the differences seen in the kids' brains, like genetic variability or socioeconomic status.

The research team is now in the process of conducting a similar, larger study, with around 80 participants so far. But rather than wait to release those results, Nomura says they felt it was important to release earlier findings more quickly to raise awareness among the public.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)