Risk of Stroke Associated With Use of Estrogen Containing Contraceptives in Women With Migraine: A Systematic Review.

Migraine with aura has been associated with increased risk of ischemic and hemorrhagic stroke. Prior studies have shown a further increase in risk in women using combined hormonal contraceptives (CHCs). This has led to guidelines recommending against use of CHCs in this population. We sought to assess whether the risk of stroke is associated with the dose of estrogen and whether there is evidence of synergism between migraine and CHCs. We also sought to assess whether an interaction effect exists between migraine and CHCs.