Hypertension — OCs frequently cause a mild elevation in blood pressure within the normal range; however, overt hypertension can occur.
The effect of current low-dose OCs was assessed in a report from the Nurses' Health Study, which prospectively evaluated almost 70,000 nurses aged 25 to 42 years. After adjustment for age, weight, smoking, family history, and other risk factors, the relative risk of hypertension compared with women who never used OCs was 1.8 for current users and 1.2 for previous users. Overall, only 41.5 cases per 10,000 person-years could be attributed to OC use; this risk rapidly declined with cessation of therapy.
Although oral contraceptive-induced hypertension is not common, its recognition is important, as hypertensive oral contraceptive users appear to be at increased risk of myocardial infarction and stroke relative to nonusers.