Since the pill first appeared on the scene, about 50 years ago, women have felt secure knowing that they had an almost foolproof way to avoid unwanted pregnancies. And that’s been mostly true.

But maybe not for all women.

If you’re overweight or obese, recent studies suggest that birth control pills might not be as effective for you as they are for more slender women:

“In one study of oral contraceptive pills, women with a body mass index (BMI) in the overweight range (a BMI of 25 or more) had a higher risk of pregnancy that those in the normal weight range. In another study of contraceptive skin patches, higher body weight — not higher BMI — was associated with higher risks of pregnancy.”

In addition to the sobering news about the lessened effectiveness of hormonal birth control, these birth control methods are thought to slightly increase a woman’s risks of heart disease, high blood pressure and other conditions. When you consider that overweight and obese women are already at increased risk of heart disease, diabetes and other ills, and that pregnancy is a riskier venture, overall, for obese women and their babies, you have a new incentive for getting your weight down.

I know it isn’t easy. I’ve struggled with weight myself and can attest to the fact that it’s a constant battle. But it’s a battle we must fight – and win. And now, we have one more reason to do it.

– Yvonne S. Thornton, MD, MPH