Seatbelts save fetuses

Apr 3 2008

A new study could have a profound effect on fetal deaths and injuries caused by car accidents.

The study, by researchers at the University of Michigan, found that about 200 fetuses each year would not be lost if pregnant women properly buckled their seatbelts every time they were in an automobile.

“It's very clear, based on this study, that pregnant women should buckle up every single time they're in a vehicle,” says senior author Mark D. Pearlman, M.D., vice-chair in the Department of Obstetrics and Gynecology at the U-M Health System. “Our study strongly suggests that about 200 fetuses each year would not lose their lives if women simply buckled up each time.” An estimated 370 fetuses die as a result of car crashes each year in the United States.

The research debunks a long-standing myth that wearing a seatbelt is not safe for pregnant women, says Pearlman, the S. Jan Behrman Professor of Reproductive Medicine.

“Some women are very concerned because the lap belt overlies their fetus. This study shows that the opposite is true, that seatbelts clearly protect the fetus,” he notes. The study appears in the new issue of the American Journal of Obstetrics & Gynecology.

The study results have led Pearlman to initiate a campaign called Safe Babi (Seatbelts Are For Everyone – Buckle All Babies In).

Pearlman teamed up with researchers from the U-M Transportation Research Institute (UMTRI), the Department of Emergency Medicine and the College of Engineering to study data from 57 severe automobile crashes involving pregnant women. The study, the first of its kind, performed detailed crash analysis, including accurate estimates of the crash severity, restraint usage and pregnancy outcome. Among the six improperly restrained women, three (50 percent) resulted in fetal death or major fetal complications. Among the 10 unbelted women, eight (80 percent) of the instances resulted in fetal death or major complications. Among the properly restrained women, 29 percent of instances resulted in death or complications.

“Given that there are seatbelts in virtually every car in America, the cost effectiveness of a project like this is truly extraordinary,” says lead author Kathleen DeSantis Klinich, Ph.D., assistant research scientist with UMTRI.

The study states that:

• The routine use of seatbelts by pregnant women will prevent 84 percent of serious fetal adverse outcomes (injuries and deaths) due to car accidents.
• If all women simply wore their seatbelts during pregnancy, approximately 200 fetal lives would be saved. (The 200 lives saved don't include the number of prevented extreme preterm births, placental abruptions that result in brain injury, etc.)
• There are more fetal deaths due to car impacts than there are deaths of children due to bicycle accidents, or deaths of children due to car accidents in the first year of life.
• Women who are in car crashes resulting in serious fetal adverse outcomes are unbelted 62 percent of the time.
• About 6 percent to 7 percent of women who are pregnant are involved in a car crash during their pregnancy. That translates to about 170,000 car crashes a year involving pregnant women.

Other published research by Pearlman shows that women whose prenatal care provider says anything at all about seatbelt use during prenatal visits are much more likely to wear their seatbelts (92 percent if the physician or nurse mentioned it versus 71 percent if they didn't), according to Pearlman. He encourages health care providers to remind all of their pregnant patients about the importance of using seatbelts.

In addition to Pearlman and Klinich, authors of the study were Carol A.C. Flannagan, Ph.D., and Jonathan D. Rupp, Ph.D., both of UMTRI; Mark Sochor, M.D., of UMTRI and the U-M Department of Emergency Medicine; and Lawrence W. Schneider, Ph.D., of UMTRI and the U-M College of Engineering's Department of Biomedical Engineering.

Financial support for the initial research described in the paper was provided by General Motors, pursuant to an agreement between GM and the U.S. Department of Transportation. The UMTRI crash database is sponsored by the Alliance of Automobile Manufacturers. Additional data collection by the Crash Injury Research and Engineering Network program was sponsored by the National Highway Traffic Safety Administration.