Oral Contraceptives, commonly known as birth control pills are known to block blood flow to the brain which may result in ischemic strokes.
However, Ischemic strokes risk is very small among women who do not have other stroke risk factors. Birth control pills may result in blood clots that block the blood vessel in the brain which prevents blood flow to the brain.
Several mechanisms were proposed to study the effect of birth control pills to ischemic stroke, of which of them is that birth control pills increases blood pressure and makes the blood hyper coagulable.
The ideal birth control pill contains low estrogen and progestin doses which will be effective in preventing pregnancy and minimizes adverse effects.
If women taking oral contraceptives have other stroke risk factors, the risk of ischemic stroke is high and in most of the cases, the use of pills is discouraged. The risk factors include high blood pressure, cigarette smoking and migraine headaches, especially migraines with sensory disturbances called the aura.