Updated February 06, 2013.

Women who take birth control or who have migraines are typically young and have a very low risk of suffering a stroke. However, their risk of stroke increases due to certain habits and behaviors, as well as with the existence of some medical conditions.

Birth Control Pills Increase Stroke Risk

Many studies have shown that women who take birth control pills have an increased risk of stroke, especially when they use pill preparations that contain more than 80 micrograms of estrogen.

Because of this, it is recommended that women on birth control pills use preparations that contain fewer than 50 micrograms of estrogen, which significantly decreases the risk.
The stroke risk from birth control pills is especially high in women who smoke, as this detrimental combination is often blamed for ischemic and hemorrhagic strokes.

Migraines with Aura Increase Stroke Risk

Women who suffer from the type of migraines heralded by an aura also have an increased risk of suffering a stroke. And although the risk is still pretty small (1.5-2 times that of people without migraine), it can become much higher in women who both have migraines with aura, and smoke cigarettes.
What is a migraine with aura you ask? These are migraines that are preceded by an unusual phenomenon such as seeing sparkling lights or wrinkly lines in the field of vision. Though rare, some auras also include abdominal pain, transient numbness or weakness on either side of the face, arm or leg, vertigo, and sometimes, a feeling of déjà vu.

_{Sources:
Bradley G Walter, Daroff B Robert, Fenichel M Gerald, Jancovic, Joseph Neurology in clinical practice, principles of diagnosis and management. Fourth Edition, Philadelphia Elsevier, 2004.}