A unique study of expectant mothers who dealt with the strain of a hurricane or major tropical storm shows that this stress can increase complications at birth.
Researchers discovered mothers living within 18 miles of a hurricane’s path during their third trimester were 60 percent more likely to have a newborn with abnormal conditions.
Infants were at risk for needing a ventilator for more than 30 minutes or experiencing meconium aspiration, which occurs when a newborn breathes in a mixture of meconium — or early feces — and amniotic fluid around the time of delivery.
Increased risk was also found following exposure to weather-related stressors in the first trimester, while evidence was less clear for exposure in the second trimester.
In the study, investigators were able to separate the impact of stress caused by the storm from other factors, such as changes in the availability of health care in a storm’s aftermath.
Researchers believe the study shows that prebirth stress can impact newborn health and call for additional research on how the preterm stress can affect a child’s later development.
“Probably the most important finding of our study is that it does seem like being subjected to stress in pregnancy has some negative effect on the baby, but that the effect is more subtle than some of the previous studies have suggested,” said lead researcher Janet Currie, Ph.D.
Dr. Anna Aizer, associate professor of economics and public policy at Brown University, who wasn’t involved in the study, said the research “really raises the bar in terms of identification of the effect of stressful events in-utero on birth outcomes.”
Meconium aspiration — usually a sign of fetal distress — and other respiratory problems that necessitate a baby being placed on a ventilator can generally be treated successfully, but the study offers new paths for future research about the long-term health of children born in the wake of stressful events such as hurricanes.
“I think there’s every reason to believe that if you have a better measure of child health — like you knew this child was having breathing problems at birth — that might be a stronger predictor of longer-term outcomes,” Currie said. “There’s a lot of interest in this whole area of how things that happen very early in life can affect future outcomes.”
Previous research into the impact of similar types of stress has found changes in length of gestation and birth weight, but the new study didn’t find a significant effect on those measures, Currie said.
Experts know that exposure or experiencing a major weather event can have a significant impact on people that go well beyond stress.
However, Currie said the researchers were able to determine that findings related to abnormal health conditions at birth generally weren’t tied to disruption of medical care or property damage caused by the storms, such as damage to an expectant mother’s home that might lead to injury or increased risk of illness.
They also found little consistent evidence that the stress associated with storms affected mothers’ behaviors, such as smoking, eating as reflected in weight gain, and use of prenatal care.
Investigators believe the storm can cause an increase in stress hormones in what is known as the neuroendocrine pathway.
“I think the takeaway finding is that it’s worth doing more focused research on those pathways and looking for more subtle effects on the fetus than just looking at birth weight and preterm delivery,” Currie said.
“And it would be really great if we could follow over time and see what happens to children who are affected by these types of events.”
The impact of stress on the neuroendocrine pathway may explain the lower birth outcomes that occur among women of low socioeconomic status.
“Previous work has shown poor mothers are exposed to more stressors. This study suggests that exposure to stress might be one of the mechanisms explaining why poor women have worse birth outcomes,” Aizer said.
“Policymakers concerned with improving the outcomes of poor families should consider these findings.”
Source: Princeton University