Birth Control Pills and Stroke
I've heard that birth control pills increase the chances of stroke in people who smoke. Is this true? How much do birth control pills increase the risk of stroke?
It is difficult to quantify the increased risk of stroke that occurs with birth control pills for several reasons. There are different types of birth control pills that contain different hormones. It is likely that different hormones (even related ones) have different stroke risks.
Also, dosage appears to play a very important role, with older, higher-dose contraceptives having a higher risk compared to newer, low-dose ones. Studies have shown widely varying results, probably largely due to such differences.
In addition, the risk varies depending on the person. Older women, women who smoke, women who get migraines, and women with other stroke risk factors (such as clotting disorders) have a higher risk of stroke with birth control pills, compared to the average woman. Keep in mind that for a typical young, healthy woman, the risk of stroke is so small that even a doubling or tripling of the risk is not necessarily dangerous.