PITTSBURGH, – Motor vehicle crashes involving pregnant women are the leading cause of traumatic fetal death, researchers from the University of Pittsburgh’s Center for Injury Research and Control (CIRCL) report in today’s Journal of the American Medical Association. While they found the detected number of deaths to be disturbing, the researchers also suggest their data substantially underestimates the problem.
Based on their findings, the authors are urging automotive industry and highway transportation safety officials to urgently search for ways to reduce crash risks and improve the safety of pregnant women and their fetuses while driving or riding in motor vehicles.
“There is an urgent need to better understand how to protect pregnant women by reducing crash risk, and if they are in a crash, how to better protect women and fetuses,” said Harold B. Weiss, M.P.H., Ph.D., associate director of CIRCL, assistant professor of neurological surgery and lead author of this study. “Furthermore, without better case identification, the magnitude and trends of the problem, who is at risk, and what circumstances carry the highest risk, remain difficult to decipher.”
Researchers looked at 16 states’ fetal death certificates from 1995 to 1997, representing 55 percent of the U.S. live births during the study, and approximately 15,000 fetal death registrations per year. Any fetal death of at least 20 weeks’ gestation as a result of an in utero traumatic injury either to itself or mother was considered a case of traumatic fetal death. Out of the 240 traumatic fetal deaths identified from these records, motor vehicle crashes were the leading cause of maternal injury related to the fetal death, representing 82 percent of the cases with listed causes.
This is the first population-based study that looks at all causes of traumatic fetal death. It supports the claim that the annual number of fetal motor vehicle-related deaths, conservatively estimated in this article at more than 369 (after partial adjustment for missed cases), far exceeds the number of infant motor vehicle-related deaths in the U.S., which averages about 180 deaths per year.
According to Dr. Weiss, “The fetus shares exactly the same crash risk as the pregnant woman, but is clearly more vulnerable since most mothers survive.” Despite this vulnerability, Weiss continued, they lack the safety advantages that infants have from child restraint systems, safer occupant positioning, and perhaps reduced crash involvement and severity. The greater incidence of estimated fetal motor vehicle related-deaths in this context, should not be surprising, though still quite tragic to the hundreds of families suffering these losses each year.”
It helps to put these numbers into the context of other highway safety and infant injury issues. For example, based on National Highway Traffic Safety Administration June 2001 update of the database of reports, the ATX and Wilderness AT Firestone tires recalled last year have been associated with 123 deaths of all ages over a several year period. The Centers for Disease Control and Prevention reported that in 1998, 376 infants died from unintentional suffocation causes, 63 from unintentional drowning, 43 from fires and burns, 9 from poisonings and 5 from firearms.
Because state fetal death registries usually don’t code or computerize the circumstances of maternal injury, to assemble a picture of the patterns of injury related fetal death, it was necessary for researchers to review narrative statements on the fetal death certificates. Like standard death certificates, fetal death certificates contain sections that include demographic information and descriptive information supplied by coroners, medical examiners and doctors on contributory causes of death. Upon close examination of these narratives, most of the targeted fetal death certificates were found to contain good information on the circumstances of the mother’s injury enabling the researchers to discern relative contributions of different causes.
Other important results of the study showed that the youngest mothers, ages 15 to 19 years old, were at highest risk. Also, placental injury was often involved and all gestational ages examined shared a substantial part of the risk.
In order to protect pregnant women and fetuses in the future, Dr. Weiss suggests that further research should be conducted. “Future safety measures should include incorporating fetal deaths in crash and injury mortality data systems so problems can be more easily tracked, requiring pregnant dummies be used in car crash tests, examining the patterns of pregnant women involved in crashes and conducting prevention research aimed at showing what really works to reduce crash risk and injury to both pregnant women and their fetuses,” added Dr. Weiss.
Other authors of the study are Thomas J. Songer, Ph.D., M.Sc., assistant professor of epidemiology at the University of Pittsburgh’s Graduate School of Public Health, and Anthony Fabio, M.P.H., Ph.D., visiting assistant professor at CIRCL and the department of neurological surgery.
This study was supported in part by National Highway Traffic Safety Administration through a grant to the University of Pittsburgh Graduate School of Public Health’s department of biostatistics.
CIRCL is an interdisciplinary, comprehensive program involving multiple departments in the School of Medicine, the Graduate School of Public Health, and the Schools of Health and Rehabilitation Sciences, Social Work and Nursing at the University of Pittsburgh. The center conducts injury control research, disseminates information on injuries, provides training for health care professionals and informs the public and community leaders on injury control measures. It is one of 11 centers in the United States to receive an official designation as an injury control research center by the Centers for Disease Control and Prevention.
For more information about CIRCL, please go to http://www.circl.pitt.edu/home
Journal
JAMA