gynecology and obstetrics
Oral Contraceptives
Key Points
Oral contraceptives (OCs) are generally well tolerated but may cause headache, nausea, bloating, or breast tenderness. Progestin-only OCs may cause irregular bleeding and must be taken at the same time every day to be effective. OCs may be taken from menarche until menopause if they have no contraindications. Combination OCs increase the risk of venous thromboembolism to 2 to 4 times the risk at baseline, but this risk is less than that associated with pregnancy. Study results vary regarding use of OCs and risk of breast cancer, but some studies have found a small increased risk in current or recent users; OCs decrease the risk of ovarian cancer and endometrial cancer. Before OCs are prescribed, a thorough patient history is required; a physical examination is not required but ideally should be done within 1 year after OCs are started. 