Many cultures hold that stress during pregnancy affects a woman's unborn child. However, there has been surprisingly little research on the topic.
Now a study published in the May/June issue of the journal Child Development finds the folklore has scientific truth to it - although not in the way you might expect.
Researchers from Johns Hopkins University in Baltimore and the National Institute of Child Health Development (NICHD) asked 137 healthy, pregnant women with low-risk, normal pregnancies to report on their levels of anxiety and stress between the 24th and 32nd weeks of their pregnancy, as well as six weeks and two years after the birth. The researchers also assessed the women's feelings about the pregnancy. Two years later, the researchers evaluated the mental and motor development of the children born to those women, as well as the toddlers' ability to control their behavior and regulate their emotions.
The researchers found that the mothers' emotions during pregnancy were indeed associated with child development - but not in the expected direction. Women who reported more stress and anxiety during pregnancy had children who were somewhat more advanced in their mental and motor development at age 2. This remained true even after taking into account the women's stress and anxiety levels after birth, which can influence child rearing in other ways.
In addition, there were no effects of prenatal stress or anxiety on the children's ability to handle their own emotions or control their behavior with one exception: children of women who reported more negative feelings about being pregnant had somewhat poorer behavioral and emotional regulation. It's not known, however, if this is a specific biological effect or whether women who were highly negative about being pregnant treated their children differently after birth.