Babies Affected By Stress in the Womb
(Ivanhoe Newswire) – Stress during pregnancy can be harmful to babies’ development and has even been linked to an increased risk of schizophrenia in males. These changes and risk factors that arise in children born to mothers who experienced heightened stress during pregnancy were not entirely understood until recently.
A new study discovered that when pregnant women are stressed, levels of a particular protein in the placenta are altered which then affects the brain development of male and female children differently.
"Now we have a marker that appears to signal to the fetus that its mother has experienced stress,” study author Tracy L. Bale, Associate Professor in the Department of Animal Biology at the University of Pennsylvania’s School of Veterinary Medicine, was quoted as saying.
In the study, female mice were exposed to various stressors like fox odor to cause mild stress during the first week of pregnancy while another group of mice were not exposed to anything stressful. The mice’s placentas were then analyzed to find a gene that differed between stressed and unstressed mothers as well as between male and female offspring.
What researchers found was a gene called OGT. OGT levels in the placentas of offspring whose mothers were exposed to stress were lower than those from the non-stressed group. The placentas of male offspring also had lower levels of protein compared to females regardless of their mothers’ exposure to stress.
Using the information gleaned from the study, researchers hypothesize that OGT protects developing brains but when mothers’ stress decreases OGT levels, the offspring become more vulnerable to certain problems. The naturally lower levels of the protein in male offspring’s placentas also explains why some neurodevelopmental diseases such as autism are more prevalent and often more severe in males.
In order to confirm that these findings could be translatable to humans, researchers tested human placentas discarded after the birth of male babies and found decreased levels of OGT in the male side of the placenta compared to the female side.
Researchers hope the varying levels of OGT could serve as a biomarker for potential neurodevelopmental problems in humans.
"If we have a marker for exposure, we can meld that with what we know about the genetic profiles that predispose individuals to these conditions and keep a close eye on children who have increased risks,” Bale concluded.
Source: Proceedings of the National Academy of Sciences, March 2013