(Ivanhoe Newswire) — A new study reveals women who exhibit signs of stress are three-times more likely to miscarry during the first three weeks of pregnancy.

For the study, University of Michigan researchers measured the stress-induced hormone cortisol in urine samples taken from 61 women three times a week for a year. Previous studies show between 31 percent and 89 percent of all conceptions result in miscarriage. Although most miscarriages happen during the first three weeks of pregnancy, a majority of the studies begin about six weeks after conception when women first notice they are pregnant.

“The only way to capture the first three weeks of pregnancy is to begin collecting their urine from before they become pregnant. That is extremely labor-intensive and expensive,” says Pablo Nepomnaschy, researcher and doctoral student at University of Michigan in Ann Arbor.

During the study, 22 pregnancies occurred in 16 women, and each woman’s cortisol levels were measured against her own baseline levels. Researchers found 90 percent of women with elevated levels of cortisol miscarried during the first three weeks of pregnancy compared to 33 percent of those with normal levels.

Researchers say it is unclear whether cortisol is directly involved with the miscarriages or not. Nepomnaschy says: “Maybe increased cortisol is understood by the body as a cue that the context is uncertain, changing, or the quality of the environment is deteriorating. The body’s response is to stop any extra activity and go back to its most basic functions.”

The study involved a small population of women, and Nepomnaschy says the next step is to attempt to replicate these results in a larger population.

This article was reported by Ivanhoe.com, SOURCE: University of Michigan, published online Feb. 20, 2006.