UW News

March 21, 2005

Pregnant women face risk after motor vehicle crashes regardless of the presence of injuries

Pregnant women who are hospitalized following motor vehicle crashes are at increased risk of adverse pregnancy outcomes, even if they are not seriously injured or not injured at all. These women are at risk for such difficulties as placental abruption and cesarean section and their babies at risk for respiratory distress syndrome and fetal death, according to a new study by investigators at the Harborview Injury Prevention & Research Center (HIPRC).

“Pregnancy Outcomes Following Hospitalization for Motor Vehicle Crashes in Washington State from 1989 to 2001” is published in the March 15 issue of the of the American Journal of Epidemiology. Melissa Schiff, M.D., M.P.H., is the study’s primary investigator. She is a University of Washington (UW) associate professor of epidemiology.

The investigators compared demographic and obstetric characteristics of 625 women hospitalized after motor vehicle crashes during pregnancy with those of pregnant women with no history of crash hospitalization. Of the women who were hospitalized, one third had no reported injuries, half had minor injuries, and one in seven had injuries classified as severe.

Although prior studies have found that crash severity is related to adverse pregnancy outcomes, the new research indicates that less severe injuries also have the potential for adverse outcomes. The researchers assessed injury diagnosis codes to classify types of injuries from motor vehicle crashes, including fractures, dislocations, sprains and strains; head injuries; internal injuries to the chest, abdomen and pelvis; open wounds; injuries to blood vessels; contusions and crushing injuries; nerve and spinal cord injuries; and superficial injuries. An injury severity score was then determined for each hospitalized woman.

To evaluate maternal and perinatal outcomes, the researchers used the Washington State Birth Event Records Database, which includes maternal and infant diagnosis and procedure codes for delivery hospitalizations. Pregnant women involved in motor vehicle crashes were compared with a randomly chosen group of pregnant women who had not been hospitalized for a crash-related injury and who experienced a childbirth or fetal death during the same period.

Pregnant women involved in motor vehicle crashes and who had no documented injuries were found to be at markedly increased risk for pre-term labor and placental abruption, and their infants were at increased risk of pre-term delivery and low birth weight, compared to the women not involved in crashes.

“In light of our findings, careful maternal and fetal monitoring following a crash is warranted,” says Schiff. “Future studies evaluating police crash data in conjunction with birth and fetal death certificates may provide additional insight into how specific types of crashes play a role in adverse pregnancy outcomes.”

In addition to Schiff, the study was conducted by Victoria Holt, Ph.D., a UW professor of epidemiology and adjunct professor of health and services, and a member (joint) at the Fred Hutchinson Cancer Research Center.

This research was supported by a grant from the Centers for Disease Control and Prevention.