By Amy Norton
NEW YORK (Reuters Health) - For pregnant women involved in a traffic accident, the impact of an airbag does not seem to raise the risks of most pregnancy complications, a new study finds.
Airbags, used along with seatbelts, are known to cut car-crash victims' risk of death and severe injury. However, concerns have been raised about the impact of an airbag on a pregnant woman's abdomen; there have been, for instance, case reports of uterine or placental rupture leading to pregnancy loss.
But until now, large-scale studies had been lacking.
In the new study, researchers analyzed data on 3,348 collisions involving pregnant women in Washington State between 2002 and 2005.
They found that for most pregnancy complications -- including placental detachment from the uterine wall, fetal distress and Cesarean delivery -- there was no evidence of a higher risk for women whose crash had involved an airbag deployment.
There was a higher rate of fetal death in accidents involving an airbag - 1 percent, versus 0.3 percent among women in accidents without an airbag deployment.
However, there were only two fetal deaths in each group, and the small numbers make it difficult to draw conclusions, the researchers note in the journal Obstetrics & Gynecology.
In the U.S., it's estimated that nearly 33,000 pregnant women are involved in car crashes each year. These accidents are a leading cause of fetal death.
Because airbags can help save lives, groups such as the American College of Obstetricians and Gynecologists (ACOG) have long advised pregnant women not to deactivate their vehicle airbags.
The current findings support those recommendations, said lead researcher Dr. Melissa A. Schiff, a professor of epidemiology at the University of Washington School of Public Health in Seattle.
She added, though, that the findings are "inconclusive" regarding both the risk of fetal death and the risk of preterm labor. The researchers did find a higher rate of preterm delivery among women whose accidents involved an airbag -- nearly 16 percent, versus 10 percent among women in crashes where no airbag deployed.
However, that difference was not statistically significant, which means the finding could have been due to chance.
Schiff said that larger studies are necessary to answer the question of whether airbags raise the risks of preterm labor or fetal death.
For now, the researcher said, pregnant women should follow the advice of ACOG and others to keep their car airbags activated. But she also stressed that seatbelts are the best protection in a crash.
"A key take-home message," Schiff said, "is that pregnant women should keep wearing their seatbelts, and wear them properly."
According to ACOG, pregnant women should always wear a lap-shoulder belt, with the lap belt sitting across the hip bones -- below the belly -- and the shoulder strap across the center of the chest. The group also recommends that women keep their seat positioned as far back from the dashboard as possible.
SOURCE: Obstetrics & Gynecology, January 2010.