Stillbirths: Researchers Find Common Causes, Mysteries Remain

Stillbirths, technically defined as the death of a fetus 20 weeks into gestation or later, are devastating to would-be mothers and occur 26,000 annually, roughly equals the number of infant deaths, according to health statistics.

Researchers from the Stillbirth Collaborative Research Network Writing Group, a collective from across the U.S., published results in two papers in the Journal of the American Medical Association Tuesday. The first paper examined risks that could predict stillbirths; the second paper explored the reasons behind stillbirths.

Clinicians found the causes for stillbirths to be wide-reaching, but much of the blame went to conditions of the womb or abnormalities in the placenta. Clinicians conducted autopsies of 512 stillbirths in the five-state study region and found distinct categories to explain the deaths. Though black women are twice as likely to have stillbirths as women with other racial/ ethnic backgrounds, the researchers didn't find any definitive answer.

The consistent and persistent racial disparity in stillbirth remains largely unexplained, said Robert M. Silver, chief of the Division of Maternal-Fetal Medicine at the University of Utah School of Medicine and senior author. It is well-documented that black women are also more likely to have spontaneous preterm birth, so perhaps there are genetic or other factors that contribute to both stillbirth and spontaneous preterm birth in black women.

The researchers found that black women had stillbirths earlier during pregnancy and said that was likely because of obstetrical complications or infection.

The research stemmed from the Eunice Kennedy Shriver national Institute of Child Health and Human Development that in 2006 began to fund the multicenter study.

Causes of deaths that occurred between 20 to 24 weeks gestation included premature labor and problems with the placenta; after 28 weeks of gestation, deaths related mainly to hypertension in the mother or umbilical cord abnormalities.

Stillbirth and preterm birth are often considered as separate entities, but this is strong evidence that the 2 are more closely linked than has been previously recognized, Jay Iams and Courtney Lynch, pediatric professors at the Ohio State University Medical Center in Columbus, wrote in a separate editorial in JAMA. Pregnancies involving fetal death near the limit of viability, including those before 20 weeks, share important commonalities with pregnancies resulting in early pre-term birth.

The reasons behind many stillbirths remain unknown; in 24 percent of the cases examined, a probable or even possible cause of death was unknown.