Birth control pills linked to increased risk of multiple sclerosis

New research suggests a possible link between birth control pills and an increased risk of multiple sclerosis among women.

The recent study shows a 35 per cent increased risk of multiple sclerosis (MS) among women who took birth control pills for at least three months before their symptoms began compared to women who did not use oral contraceptives.

"These findings suggest that using hormonal contraceptives may be contributing, at least in part, to the rise in the rate of MS among women," says lead author Dr. Kerstin Hellwig from the medical center Kaiser Permanente Southern California.

Researchers examined 305 women between the ages of 14 to 48 who were diagnosed with MS or had pre-MS symptoms between 2008 and 2011. These women were compared against 3,050 women who did not have MS, reports Fox News. All of the women were assessed for their birth control use up to three years prior.

The result, which will be presented at the American Academy of Neurology annual meeting in April, show women who used oral contraceptives had a 35 per cent increased risk of developing MS compared to those who did not use them. Women who stopped taking birth control pills at least one month before MS symptoms started were 50 per cent more likely to develop the disease.

“We say the use of birth control might explain a little bit of the increasing incidence [of MS] among women, but only to a small amount," says Hellwig, who suggests that hormones in the contraceptives may play a role in the development of MS.

The autoimmune disease affects the central nervous system, and while the direct cause of it is unclear, scientists speculate that it is linked to environmental stressors, genes and smoking.

Canadians have one of the highest rates of MS in the world, and women are three times more likely to develop the disease.

Hellwig is careful to note that her team's findings do not suggest women should stop taking birth control pills, as researchers haven't determined the exact cause-and-effect relationship between the two factors.