(RxWiki News) It may sound obvious to say drivers should wear their seatbelts. For pregnant women, however, this warning is especially important to protect their child as well.
A recent study found that pregnant women involved in a car accident were more likely to experience certain negative outcomes with their pregnancies.
Pregnant women involved in a car crash while driving were more likely to have their water break early or to give birth early.
They were also more likely to have a dangerous placental complication or to have a stillbirth.
The women at highest risk, however, were those not wearing a seatbelt or those who had been involved in multiple crashes while pregnant.
"Wear seatbelts and drive defensively."
The study, led by Catherine J. Vladutiu, PhD, of the Department of Epidemiology at Gillings School of Global Public Health at the University of North Carolina, looked at outcomes of pregnancies among women involved in car crashes.
The researchers examined the pregnancies of 878,546 women, aged 16 to 46, who gave birth to a single child in North Carolina between 2001 and 2008.
Among these women, 2.9 percent of them were drivers in one or more motor vehicle accidents during that seven-year period.
About 23 percent more of these women who were in car crashes had preterm births (preemies delivered before their due date) than pregnant women not in car crashes.
There were also 34 percent more placental abruptions that occurred among pregnant women who had been in car crashes.
A placental abruption is a pregnancy complication in which the placenta detaches from a woman's uterus.
In addition, 32 percent more pregnant women in car crashes had their water break early (premature rupture of membranes) than pregnant women not in crashes.
The rates of stillbirth were a little higher among pregnant women in crashes as well, with 22 percent more of these women experiencing stillbirth than women not in crashes.
When the researchers looked only at women who had been in more than one car accident while pregnant, the risks increased.
Preterm birth occurred 1.5 times more often (54 percent more) among women in more than one car accident while pregnant than among women not in a car accident.
Twice as many pregnant women involved in car crashes for a second time had their water break early than pregnant women not in car crashes.
The rates were especially high for stillbirth and placental abruption among women in multiple motor vehicle accidents.
Stillbirth occurred nearly five time more often among pregnant women involved in two or more car crashes, compared to pregnant women not involved in car crashes.
Placental abruption occurred almost three times more often among pregnant women in multiple accidents, compared to women in no accident.
Another factor influencing outcomes was seatbelt use. Among pregnant women not wearing a seatbelt, 2.7 times as many (almost three times) had a stillbirth compared to pregnant women not involved in a car crash.
"Crashes while driving during pregnancy were associated with elevated rates of adverse pregnancy outcomes, and multiple crashes were associated with even higher rates of adverse pregnancy outcomes," the authors wrote. "Crashes were especially harmful if drivers were unbelted."
In calculating these risks, the researchers had taken into account the women's age, race/ethnicity, education level, use of tobacco while pregnant, use of alcohol while pregnant, number of children and her start of prenatal medical care.
These were all factors that might have influenced the women's outcomes independently from the car crashes until the researchers adjusted their findings for them.
The study was published October 8 in the American Journal of Preventive Medicine. The authors declared no conflicts of interest.
The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.