Pregnancy linked to car crash risk: study

NEW YORK (Reuters Health) - Women are at increased risk of being seriously injured during a motor vehicle accident during the second trimester of pregnancy, according to a new study from Canada.

Pregnant women were 42 percent more likely to be involved in a motor vehicle accident that sent them to an emergency room, compared to when they weren’t carrying a child, researchers found.

“A normal pregnancy is usually accompanied by a lot of fatigue, nausea, mood fluctuations, anxieties and distractions which may all contribute to distracted driving,” Dr. Donald Redelmeier, the study’s lead author from the University of Toronto, told Reuters Health.

Redelmeier, who is also an internist at Sunnybrook Health Sciences Centre in Toronto, said he got curious about the risk of vehicle crashes during pregnancy, because pregnant women would ask about the danger in other activities, such as riding a rollercoaster.

“Never once was I asked about road safety despite it being a larger risk to mother and child,” he said.

For the new study, he and his colleagues analyzed data on all adult women who gave birth in the Canadian province of Ontario between April 2006 and March 2011.

They compared the women’s crash rates before and after pregnancy to see if there was a difference.

Over half a million women gave birth and accounted for about 8,000 crashes as drivers during that time.

The researchers found that the rate of accidents was about 4.6 crashes per 1,000 women before pregnancy, compared to 7.7 crashes per 1,000 women during their second trimester.

The increased risk was present regardless of a woman’s background and demographics. It also didn’t seem to matter whether the woman already had children.

The crash rate fell before delivery and continued to fall after birth, the researchers report in the Canadian medical journal CMAJ.

While the study can’t say why the women’s risk of car crashes increased during the middle of their pregnancies, Redelmeier said it may have something to do with the symptoms that result from wide fluctuations in hormones.

“That’s what the factor is for the neurological changes, which are usually minor, but these minor changes can catch up to you when you’re operating a motor vehicle,” he said.

Despite the increased risk, Redelmeier added that women shouldn’t stop driving, because the crashes could be avoided by following standard safety advice. That includes obeying speed limits, stop and yield signs.

He added that doctors should remind pregnant women during routine visits to be especially cautious when driving.

“If there is nothing more pressing that’s the time to take a moment and mention the importance of road safety advice,” Redelmeier said. “You don’t want any pregnant women ending up in my emergency department.”

SOURCE: CMAJ, online May 12, 2014.