Birth Control Pills Increase Risk of Ischemic Stroke

While risk has been found to be very small for healthy young women without other stroke risk factors, oral contraceptives have been found to increase the risk of ischemic stroke.

At least we know that birth control pills do not increase the risk of hemorrhagic strokes, which are caused by bleeding in the brain. Ischemic strokes on the other hand, which account for about 85 percent of all strokes, are caused by blood clots.

Oral contraceptives have been thought to increase stroke risks because of a few reasons—one being that they could be responsible for raising blood pressure, which makes blood hypercoagulable (more likely to clot).

When prescribing hormonal contraceptives, physicians should consider the type of and dosage of estrogen and progestin as well as the route of administration. Neurologists Sarkis Morales-Vidal, MD, and José Biller, MD, wrote, “The ideal drug is one with the lowest estrogen and progestin doses that will be effective in preventing pregnancy while minimizing adverse effects,” in their report titled “Hormonal Contraception and Stroke.”

Drs. Morales and Biller also said that women with other stroke risk factors have higher risk when taking oral contraceptives, therefore they should stray away from using them. These risk factors include high blood pressure, cigarette smoking, as well as migraine headaches, especially those with sensory disturbances called aura.

A previous study found that women may not always be adequately screened for these risk factors. Only 15 percent recalled being advised not to start oral contraceptives and only 36 percent remembered being told to stop. Despite being told to discontinue taking oral contraceptives, 15 percent of these women continued to do so. With this information, Drs. Morales and Biller highlighted the need to improve physician counseling and patient compliance.