Stress May Make It Harder to Get Pregnant

(August 13, 2010) - The old advice, "just relax and it will happen," about getting pregnant may have some real truth to it. A new study supports the widespread belief that stress (Read about "Stress") may reduce a woman's chance of becoming pregnant. (Read about "Healthy Pregnancy") The study is the first of its kind to document, among women without a history of fertility problems (Read about "Infertility"), an association between high levels of a substance indicative of stress and a reduced chance of becoming pregnant.

The researchers showed that women who had higher levels of a substance called alpha-amylase were less likely to get pregnant than were women with lower levels of the substance. Alpha-amylase is secreted into saliva by the parotid gland, the largest of the salivary glands. Although alpha-amylase digests starch, in recent years many researchers have used it as a barometer of the body's response to physical or psychological stress. The substance is secreted when the nervous system (Read about "Nervous System") produces catecholamines, compounds that initiate a type of stress response.

"The study results suggest that finding safe ways to alleviate stress may play a role in helping couples become pregnant," said Alan E. Guttmacher, M.D., director of the NICHD.

The researchers found that, all other factors being equal, women with high alpha-amylase levels were less likely to conceive than were women with low levels, during the fertile window - the six days when conception is most likely to occur. The researchers did not find a correlation between cortisol levels and the chances of conception.

"Overall, the 25 percent of women in the study who had the highest alpha-amylase levels had roughly an estimated 12 percent reduction in getting pregnant each cycle in comparison to women with the lowest concentrations," said the study's first author, Germaine Buck Louis, Ph.D., M.S., director of the NICHD's Division of Epidemiology, Statistics, and Prevention Research.