Despite their elevated risk very few women who use oral contraceptives will experience an ischemic stroke.

To determine whether risk of stroke and oral contraceptive (OC) use are related investigators searched the medical literature for relevant studies and conducted a meta-analysis including the 16 studies conducted in the past. Overall the relative risk (RR) of ischemic stroke among current users of OCs has been nearly 3 times than among nonusers (RR 2.8). Limiting the analysis to case-control studies that stratified data by estrogen dosage smoking and hypertension and to those that used hospital controls reduces the RR of ischemic stroke to 1.9 times the risk among nonusers. This represents 4 additional strokes per 100000 women each year. The investigators suggest that the risk of stroke associated with pill use has declined over the last 40 years as the dosage of estrogen content of OCs has decreased. They conclude that although women currently using the pill have an elevated risk of ischemic stroke the absolute effect is small with current dosages.