Stressful life events may increase stillbirth risk, NIH network study finds

Pregnant women who experienced financial, emotional, or other personal stress in the year before their delivery had an increased chance of having a stillbirth, say researchers who conducted a National Institutes of Health network study.

Stillbirth is the death of a fetus at 20 or more weeks of pregnancy. According to the National Center for Health Statistics, in 2006, there was one stillbirth for every 167 births.

The researchers asked more than 2,000 women a series of questions, including whether they had lost a job or had a loved one in the hospital in the year before they gave birth.

Whether or not the pregnancy ended in stillbirth, most women reported having experienced at least one stressful life event in the previous year. The researchers found that 83 percent of women who had a stillbirth and 75 percent of women who had a live birth reported a stressful life event. Almost 1 in 5 women with stillbirths and 1 in 10 women with livebirths in this study reported recently experiencing 5 or more stressful life events. This study measured the occurrence of a list of significant life events, and did not include the woman's assessment of how stressful the event was to her.

Women reporting a greater number of stressful events were more likely to have a stillbirth. Two stressful events increased a woman's odds of stillbirth by about 40 percent, the researchers' analysis showed. A woman experiencing five or more stressful events was nearly 2.5 times more likely to have a stillbirth than a woman who had experienced none. Women who reported three or four significant life event factors (financial, emotional, traumatic or partner-related) remained at increased risk for stillbirth after accounting for other stillbirth risk factors, such as sociodemographic characteristics and prior pregnancy history.

Non-Hispanic black women were more likely to report experiencing stressful events than were non-Hispanic white women and Hispanic women. Black women also reported a greater number of stressful events than did their white and Hispanic counterparts. This finding may partly explain why black women have higher rates of stillbirth than non-Hispanic white or Hispanic women, the researchers said.

"We documented how significant stressors are highly prevalent in pregnant women's lives," said study co-author Marian Willinger, Ph.D., acting chief of the Pregnancy and Perinatology Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), one of two NIH entities funding the research. "This reinforces the need for health care providers to ask expectant mothers about what is going on in their lives, monitor stressful life events and to offer support as part of prenatal care."

The NIH Office of Research in Women's Health also funded the study.

"Because 1 in 5 pregnant women has three or more stressful events in the year leading up to delivery, the potential public health impact of effective interventions could be substantial and help increase the delivery of healthy babies," added lead author Dr. Carol Hogue, Terry Professor of Maternal and Child Health at Emory University's Rollins School of Public Health, Atlanta.