Unborn children that are exposed to excess levels of stress while in the womb are at a higher risk of obesity as adults, a new study finds.
Previous studies have highlighted that pregnant women who experience stress put their children at a higher risk of weight problems when they reach between 10 and 13 years of age. Aarhus University now looks at the association between prenatal stress and obesity risk as adults.
"Overall our results indicate that stress can create a programming of the unborn child that makes it susceptible to putting on weight after birth," said PhD Lena Hohwü from the Department of Public Health at Aarhus University, in a press statement. "So even though we still have a lot of research to do in this area, we have added a little piece to our understanding of why we are experiencing an obesity epidemic, in which one in five children in Denmark are overweight -- and where most of them will remain overweight as adults."
The study was conducted between 2006 and 2011 on 119,908 young men. Study authors measured their body mass index. Many of these men's mothers had lost a close relative just before or during the pregnancy. Researchers found that these men suffered from different degrees of increased risk of overweight and obesity, depending on the relation of the relative to the mother. Researchers found that sons born to mothers who had lost their husband just before or during the pregnancy experienced the highest obesity risk. Such men were twice more likely to be obese or overweight as adults.
"We have specifically investigated the stress factor that occurs when the child's mother loses a close relative just before or during pregnancy, that is, before the child is born. We have designated this as 'an indicator of severe stress' that can double the risk of developing obesity in adulthood," said Hohwü. "But as this type of stress is fortunately rare, we are currently investigating whether there is a more general effect of stress. We are therefore looking at the significance of divorce and the stress hormone cortisol during pregnancy."
A study conducted earlier this year also found that prenatal stress increases the risk of asthma and autism in children. Researchers at the Douglas Mental Health University Institute found that such children start showing some form of autistic behavior by 6 years of age.
The current study was published online in the journal PloS ONE. Funding for the research was received from European Research Council and the Danish Medical Research Council.
