Multiple Sclerosis Risk Tied to Some Oral Contraceptives

OSTON — Women using combined oral contraceptives containing norethindrone or levonorgestrel were substantially more likely to develop multiple sclerosis (MS) than those not on birth control pills, analysis of a large claims database indicated.

Among some 4,300 women in Kaiser Permanente’s Southern California system from 2008 to 2011, those whose most recent oral contraceptive contained norethindrone had a 57% higher risk of definite MS or clinically isolated syndrome (CIS) (odds ratio 1.57, 95% CI 1.16-2.12) compared with plan members who had no record of oral contraceptive use, said Annette Langer-Gould, MD, PhD, of Kaiser’s Southern California Los Angeles Medical Center.

Oral contraceptive users whose most recent product contained levonorgestrel showed a similar increase in risk, with an odds ratio of 1.75 (95% CI 1.29-2.37), Langer-Gould said during a poster session here at theEuropean Committee for Treatment and Research in Multiple Sclerosis annual meeting, held jointly this year with its North American counterpart.

But those using contraceptives containing another progestin compound, drospirenone, did not show any increase in MS risk (OR 1.02, 95% 0.64-1.62), she said.

This pattern of results was the same, although the specific odds ratios changed somewhat, when the analysis examined the oral contraceptives that plan members had used the most — as opposed to just the ones they used most recently — recognizing that many women may switch from one type of product to another over time.

The findings shed new light on a previous Kaiser study that had found a 35% increase in MS risk with oral contraceptives generally, Langer-Gould said.

~~~~~~~~~~~~~~~~~~~~

 Keep CURRENT and up to date, with MS News and Information

Sign-up for emails 

Visit our MS Learning Channel on YouTube: http://www.youtube.com/msviewsandnews