The Risks of Oral Contraceptive Pills

Oral contraceptive pills have been associated with increased risk for myocardial infarction, stroke, and venous thromboembolism. Studies have been published recently that suggest that these risks are minimal in appropriately chosen low-risk women. Stroke is a very uncommon event in childbearing women, occurring in approximately 11 per 100,000 women over 1 year. Thus, even a doubling of this risk with oral contraceptive pills would have minimal effect on attributable risk. The estimated risk of myocardial infarction associated with oral contraceptive pill use in nonsmokers is 3 per million women over 1 year. The estimated risk of venous thromboembolism attributable to oral contraceptive pills is less than 3 per 10,000 women per year. Additionally, the literature suggests that there may be an increased risk of breast cancer associated with long-term oral contraceptive pill use in women under the age of 35. However, because the incidence of breast cancer is so low in this population, the attributable risk of breast cancer from birth control pill use is small.