What is the risk of stroke associated with any oral contraceptive (OC) use?
A meta-analysis of 16 case-control and cohort studies between 1960 and 1999 estimated a 2.75-fold increased odds (95% CI, 2.24 3.38) of stroke associated with any OC use. A later meta-analysis of 20 studies published between 1970 and 2000 that separated the studies by design (case-control versus cohort) found no increased risk of stroke in the cohort studies but an increased risk with OC use in case-control studies. Lastly, a systematic review of progestogen-only OCs revealed no significant increased risk of stroke with this form of contraceptive.