Women who deliver a stillborn infant — but who have no history of depression — may be at a higher risk for long-lasting depression, conclude researchers funded by the National Institutes of Health (NIH). The depression may last beyond the six months most people require to recover from a major loss and persist for as long as 36 months.

The findings were published online in Paediatric and Perinatal Epidemiology by researchers in the NIH's Stillbirth Collaborative Research Network (SCRN), which seeks to understand the causes of stillbirth, improve reporting of stillbirths that have occurred, and develop ways to prevent stillbirth. According to SCRN, stillbirth is the death of a baby at or after the 20th week of pregnancy. It occurs in 1 out of 160 pregnancies in the United States. Since 2003, the stillbirth rate has remained at about 26,000 each year.

"This study is the first to show definitively that women who have no history of depression may face a risk for depression many months after a stillbirth," says study author Marian Willinger, PhD, of the NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development, which supports the SCRN and participates in its research. "The findings suggest that women who have had a stillbirth may require longer term monitoring for depressive illness and referral for treatment when they need it."

Additional funding was provided by NIH's Office of Research in Women's Health.

"Earlier studies have found that women with a history of depression are especially vulnerable to persistent depression after a stillbirth, even after the subsequent birth of a healthy child," says the study's first author, Carol Hogue, PhD, director of the Women's and Children's Center at Emory University's Rollins School of Public Health in Atlanta. "Symptoms of depression are a normal part of grieving after a stillbirth," Dr. Hogue says. "But depressive symptoms that don't gradually resolve within six months of the loss can persist and become debilitating."

The SCRN enrolled women at 59 hospitals in Rhode Island, Massachusetts, Georgia, Texas and Utah. From 2006 to 2008, the researchers enrolled 275 women who delivered a stillborn infant and 522 women who delivered a healthy live baby after 37 weeks of pregnancy. In 2009, the researchers again contacted the women and asked them to complete a questionnaire, known as the Edinburgh Depression Scale, designed to gauge whether women are experiencing symptoms of depression. Physicians use the scale to identify women for referral to a mental health professional for further testing. 

Among the more than 76 percent of women who did not have a history of depression, slightly more than 13 percent of those who had a stillbirth received a high depression score. In comparison, only five percent who had a live birth had a high depression score. After accounting for other factors related to depression and stillbirth within this group, the researchers found that women who had a stillbirth were twice as likely to have a high depression score compared to women who had a live birth. Among the women responding to the questionnaire from 24 to 36 months after they had delivered, the difference was greater: 17.6 percent of women who had a stillbirth had a high depression score compared to 1.9 percent of women who had a live birth. 

"Our findings indicate that it would be a good idea to screen women who have had a stillbirth for depression for at least three years after the stillbirth," Dr. Hogue says.

The study authors call for additional research to help women manage the grieving process after stillbirth to lower the later risk of depression.

Information on diagnosing and treating depression is available from NIH's National Institute of Mental Health.