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Obese Women Who Take Birth Control Pills May Have Higher Stroke Risk

April 21, 2016

Obese women who take birth control pills are more likely to experience a rare form of stroke, according to a recent study.

The study, published in the journal JAMA Neurology, included 186 adults who had cerebral venous thrombosis (CVT), a rare disorder which causes blood clots in the skull’s cerebral veins and the major dural sinuses, which are important pathways that facilitate blood flow to the brain.

The study found that obese women who took birth control were 30 times more likely to develop CVT compared to normal weight women who did not take oral contraceptives. Many of the patients with CVT also were younger, with a median age of 40.

Researchers were surprised to discover that the higher stroke risk associated with birth control pills was only evident in obese women, since birth control is known to increase the risk of blood clots in women who take them. However, researchers say that since obese women and birth control users, respectively, have a higher risk of blood clots, it makes sense that obese women who take oral contraceptives — which combines both these risk factors — would have an increased likelihood of stroke.

However, CVT, while serious, affects only a small percentage of the population. One in 100,000 people get the condition each year, amounting to 4,200 annual cases in the U.S. CVT is harder to diagnose, but compared to other forms of stroke, it has a higher likelihood of recovery. Five out of six patients typically recover after CVT.

Still, the study highlights the dangers obesity poses to women during their birthing years. We’ve addressed this in a previous blog post about the dangers of obesity and pregnancy. In that post, I highlighted a previous study that showed infants born to obese mothers (those with a BMI of 30 or higher) may have a higher risk of death.

Obesity can pose several challenges to women in terms of family planning, whether they are trying to prevent pregnancy or become pregnant.  If they are on birth control, being obese can increase their risk for several health issues, including blood clots. If they are obese and become pregnant, they have an increased risk of gestational diabetes and preeclampsia, a complication that involves high blood pressure and damage to other organs.

The study in JAMA Neurology suggests that we need to do more to educate women with multiple risk factors about how birth control may elevate their risk for stroke. However, it’s also important to note that the study showed a correlation — not a direct cause and effect — between obesity, birth control and CVT. Still, women who are obese may benefit from using alternative methods of birth control that don’t contain hormones, like a diaphragm or intrauterine device (IUD).

Obesity is a serious health condition, one that can increase your risk for other health issues. If you are struggling with your weight, get support. Talk to your doctor about weight loss programs, nutritional counseling and other resources that can help you lose weight and make an effort to progressively change your life in ways that will improve your long-term health.