June 29, 2012
Study Focuses On Environmental Stresses On Pregnancy
Connie K. Ho for redOrbit.com — Your Universe Online
Pregnancy can be stressful enough. There´s the need to worry about eating the right thing, completing the correct prenatal exercises, among a heap of tasks. Add an environmental issue on top of that and pregnant females have more to worry about. Princeton University researchers recently found that expectant mothers who had to deal with the stress of a major hurricane or tropical storm passing by during their pregnancy suffered elevated risk; their children had a higher likelihood of having abnormal health conditions at birth. The researchers believe that the study will help physicians and expectant mothers better understand the effects of stress on pregnancy.
Primarily, the experiment focused on innovative and effective methods in analyzing the effect of prebirth stress on newborns. Researchers believe that the project´s results allow for further studies on the potential impact on the children in later stages.
"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," explained Janet Currie, who serves as Princeton´s Henry Putnam Professor of Economics and Public Affairs at the Woodrow Wilson School of Public and International Affairs, in a prepared statement.
The study utilized birth records from Texas, as well as meteorological information, to determine babies who were born with a major tropical storm or hurricane nearby. The children, who were born between 1996 and 2008, were compared with siblings whose births did not concur with a major weather event. The investigators discovered that mothers who lived within 30 kilometers of a hurricane´s path during the third trimester had a 60 percent higher chance of having a newborn who demonstrated abnormal conditions. Some of the consequences of the environment included having to use a ventilator for over 30 minutes or having to experience meconium aspiration. Meconium aspiration is found when a newborn breathes in a combination of meconium, otherwise known as early feces, and amniotic fluid when it is delivered. There were also more risks for the infant after exposure to weather-related stressors during the first trimester, while there was less data that showed the influence of stress on infants during the second trimester. Overall, the scientists were able to separate the effect of stress caused by the storm from other factors, like the differences in the availability of health care following a storm´s damage on the community.
"Previous work has not really been able to isolate the effect as well as Currie and Rossin-Slater have," noted Anne Aizer, an associate professor of economics and public policy at Brown University unaffiliated with the study, in the statement.
With the experiment, respiratory problems such as meconium aspiration acted as signs of fetal stress and required that babies were placed on a ventilator. When they were placed on the ventilator, these infants could be treated successfully. The findings of the project showed that there can be new options for research regarding the long-term health of children who were born during stressful events, like during a hurricane.
"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," commented lead researcher Currie, the director of the Center for Health and Wellbeing at Princeton, in the statement. "There's a lot of interest in this whole area of how things that happen very early in life can affect future outcomes."
Researchers believe that, while experiencing a hurricane or a tropical storm during pregnancy can be stressful, the findings show that the stress wasn´t related to change in medical care or property damage resulting from the storm. They also found little evidence that showed that stress affected mothers´ behaviors. However, the project demonstrated an increase in stress hormones in the endocrine 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," remarked Currie, who conducted the study along with Columbia University Department of Economics doctoral candidate Maya Rossin-Slater, in the statement. "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."
Furthermore, the results of the research could have further implications than just natural disasters.
"Previous work has shown poor mothers are exposed to more stressors. Currie and Rossin-Slater's work suggests that exposure to stress might be one of the mechanisms explaining why poor women have worse birth outcomes," Aizer, whose previous research has focused on topics associated with well-being of children, mentioned in the statement. "Policymakers concerned with improving the outcomes of poor families should consider these findings."
The study, which is described in a working paper circulated in May by the National Bureau of Economic Research, was supported by funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development.