The phrase 'obesity epidemic' often pops up in the news and, with this kind of media exposure along with increasing levels of obesity, quite a bit of research is being conducted to identify its possible causes. Studies are emerging that link the risk of obesity to factors that can be traced come all the way to the womb. One of these studies, released last month by PloS One and conducted by researchers at Aarhus University, links the anxiety levels of mothers during pregnancy to the risk of obesity in their children.

Similar studies have been conducted before, showing that anxiety and stress during pregnancy are associated with higher rates of obesity in 10-13 year olds, and additionally in three year olds. This study goes even further, however, examining how anxiety during pregnancy can influence rates of obesity in these children years later, as adults.

The Statistics

Researchers noted that grief is identified as one of the main causes of severe stress and anxiety. With this in mind, they recruited Danish women who experienced the death of a relative prior to or during their pregnancies. They then followed the women's male offspring as they aged, examining their BMI and rates of obesity once they reached early adulthood.

They found that the sons of the women who experienced loss just before or during pregnancy held significantly higher rates of obesity. In fact, for women who specifically lost their husbands, their sons suffered twice the risk of developing obesity in adulthood when compared to the national average. Risk was heightened when mourning was experienced during the 1st and 3rd trimesters. No significant association was found when the death of a relative was experienced after the birth of the child, indicating that anxiety during pregnancy may be affecting the genetics of children.

Fetal Programming and Maternal Anxiety

This study suggests that a highly stressful pregnancy may actually result in fetal programming. Lena Howhu, Ph.D., who conducted the study, stated that “stress can create a programming of the unborn child that makes it susceptible to putting on weight after birth."

However, the death of a very close relative is no doubt the extreme, and Howhu added that researchers “are currently investigating whether there is a more general effect of stress… [and] are therefore looking at the significance of divorce and the stress hormone cortisol during pregnancy."

Date of original publication:


Lena Hohwü, Jiong Li, Jørn Olsen, Thorkild I. A. Sørensen, Carsten Obel. Severe Maternal Stress Exposure Due to Bereavement before, during and after Pregnancy and Risk of Overweight and Obesity in Young Adult Men: A Danish National Cohort Study. PLoS ONE, 2014; DOI:10.1371/journal.pone.0097490