Safety is a primary concern for pregnant women -- so much so that some mothers-to-be won't use seat belts for fear of harming their unborn children.
That, according to researchers from Wake Forest University, is the wrong approach.
Wearing a seatbelt actually reduces the risk of early delivery or losing the baby, said Dr. Stacie Zelman, who studied almost 2,500 pregnant women who were involved in car crashes.
She found that having both an airbag and a seatbelt were most protective against complications or loss of the baby.
"Using restraints is actually beneficial in this population of patients," Zelman said. She reported the results of her meta-analysis at the meeting of the Society for Academic Emergency Medicine in New Orleans.
She said that trauma during pregnancy is a serious cause of injury and death for both the fetus and the mother, but some pregnant women don't wear seatbelts out of fear that they might harm their unborn child.
"There's a lot of belief that wearing a seatbelt, if you're in an accident, will actually harm the fetus just by the nature of the restraint, and that having an airbag go off will cause more trauma than the accident itself," Zelman said.
So to determine whether wearing seatbelts actually has an effect on the rate of early delivery or fetal loss after a car crash, Zelman and her team looked at data from the National Trauma Database registry.
Of more than two million patients, the researchers found 2,422 patients who were pregnant when they were involved in a motor vehicle accident.
While 152 had fetal loss or an early delivery, 2,270 had no complications.
Only 77 of the 1,329 women who were wearing a seatbelt -- 5.8 percent -- had a complication, and only five of the 104 women who had an airbag deploy during their crash -- 4.8 percent -- had a complication.
And 11 of the 287 women who wore their seatbelt and experienced an airbag inflation -- 3.8 percent -- had a complication.
On the other hand, of the 702 women who were unrestrained, 59 experienced a complication, at a rate of 8.4 percent.
"Having both [the seatbelt and the airbag] was the most protective," Zelman said. "But even the airbag only is still beneficial, even if [the patient] is not wearing a seatbelt because it does restrain you versus ... being ejected from vehicle or banging into the dashboard."
If women wore a seatbelt, they had a 33 percent reduced risk of pregnancy-related complications, and they had a 45 percent reduced risk of complications if an airbag deployed.
But having the protection of both a seatbelt and an airbag carried a 57 percent decreased risk of complications.
Zelman added that the fetus "really has no protection so your seatbelt and airbag are really your first line in preventing blunt trauma to that portion of the body."
According to the American Academy of Family Physicians, the proper way for a pregnant woman to wear a seatbelt is with the lap strap under the belly and across the hips, as high as possible on the thighs. The shoulder strap should pass between the breasts and off to the side of the belly. Seat belt straps should never be worn directly across the belly. If necessary, adjust the height of the shoulder strap for the best fit; the belt should fit as snugly as possible.