Experiencing financial or emotional setback even a year before delivery can increase the risk of stillbirth and other complications during childbirth, according to a new study from National Institute of Health.

The study included more than 2,000 women. All the participants were asked to complete a questionnaire which included questions about recent job losses or other emotional setbacks in the previous year.

A stillbirth is when a woman loses a pregnancy after she's past the 20th week, says Medline Plus. In about half of stillbirths, it isn't possible to know why the baby died. There is about one stillbirth in every 167 births, according to 2006 data.

Almost one in every 5 women whose pregnancy had ended in stillbirth reported a stressful event in the past year. Two stressful events in a year raised the risk of stillbirth by 40 percent, while a woman experiencing five or more setbacks a year has a 2.5 times higher risk of having a stillbirth. These risks remained even after the researchers accounted for other factors like prior pregnancy risk.

"We documented how significant stressors are highly prevalent in pregnant women's lives. 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," said Marian Willinger, Ph.D., from the Pregnancy and Perinatology Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and co-author of the study.

In the study, non-Hispanic black women were more likely to report stressful events than white or Hispanic women. Researchers said that this study may partly explain why the risk of stillbirth is higher in black women, according to a news release from NIH.

"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 Dr. Carol Hogue, from Emory University's Rollins School of Public Health, Atlanta, and lead author of the study.

The study is published in the American Journal of Epidemiology.