From the moment they learn they’re pregnant, many women obsess over things like whether it’s safe to eat sushi or soak in a hot tub or continue with daily spin classes. I can remember quizzing my own doctor a lot when pregnant with my first: Can I fly overseas? Am I allowed to eat cheese? Is wine strictly off limits? My list of questions was endless.
One thing that never occurred to me, however, was whether it was safe to drive. It seemed like the obvious answer was yes.
Surprisingly, a study published in the Canadian Medical Association Journal says otherwise. Researchers looked at the medical records of more than 500,000 mothers in Ontario and found that expectant women are 42 percent more likely to have a serious traffic accident during the second trimester than in the three years prior to becoming pregnant. During this time, the rate of emergency room visits because of traffic accidents rose from about 4.3 visits per year per 1,000 women to 7.7 visits per year per 1,000 women.
“Fatigue, nausea, distraction—these can all contribute to driver error,” says lead researcher Donald Redelmeier, a professor of medicine at the University of Toronto and a staff physician at Sunnybrook Health Sciences Centre (he was one of the first to study the link between cellphones and car accidents, way back in 1997).
Redelmeier isn’t suggesting pregnant women refrain from driving. Rather, he’s reminding them to drive a little more carefully (for example, by always signalling turns and obeying the speed limit). If Redelmeier had his way, prenatal care would always include recommendations for safe driving.
“I often look after pregnant women who will ask me about flights and scuba diving and hot tubs and medications and many other things, but I’m almost never asked about vehicle crashes, despite them frequently causing serious injury to mother and baby,” he says.
Interestingly, the study also found that the risk of crashing was significantly lower in the third trimester than it was before pregnancy—and it fell even further in the first year after the women gave birth. In other words, the risk is greatest in the second trimester, when most women are over the nausea and fatigue but not yet into the sleepless, uncomfortable phase.
What’s going on? According to Redelmeier, a fundamental aspect of all accidents is a false sense of security.
“Women in the second trimester are feeling a lot better, on average, than in the first trimester and a lot better than they’re going to be feeling in the third. That can open up this window of overconfidence—or increased stress as they’re rushing around, trying to get everything done before the baby comes,” he says, adding that by the third trimester, defences are raised.
Some women are opting not to drive at all during their last trimester. Robyn Tenenbaum, a Toronto teacher and mom to four-month-old twins, was concerned about the distinct lack of space between her growing baby belly and the steering wheel (her doctor concurred).
“It got to the point at around 30 weeks where there was half an inch between the two,” she recalls. “If there’s an accident—even a small one—that’s not enough room to protect you.”
Tenenbaum’s decision to hand over her keys was based on her worry that even a minor fender-bender could have been devastating. But there are other reasons some doctors caution expectant moms about driving. Ori Nevo, a maternal fetal medicine specialist at Sunnybrook Health Sciences Centre in Toronto, says he also occasionally recommends women refrain from driving.
“Some patients may tell us that if they sit for a long period of time, they feel nauseous or dizzy, so we suggest not driving,” Nevo says. “Or if it looks like it’s difficult for them to walk or be mobile. It all depends on what a person feels and if they can manage to sit properly behind the wheel.”
While there are no clear rules, it all comes down to common sense and your circumstances. Tenenbaum had family members who could drive her around. For other women, it’s a matter of simply paying better attention to the road, as Redelmeier’s study suggests. It’s a good reminder for anyone, pregnant or not, who gets behind the wheel.
A version of this article appeared in our May 2016 issue with the headline, “Driving while pregnant,” p. 41.