gynecology and obstetrics
Oral Contraceptives
Progestin only oral contraceptives
To be effective, progestin-only OCs must be taken at the same time of day, every day. The same dose is taken daily, and no inactive pills are included. Breakthrough bleeding is a common adverse effect. Progestin-only OCs provide effective contraception primarily by thickening the cervical mucus and preventing sperm from passing through the cervical canal and endometrial cavity to fertilize the egg. In some cycles, these OCs also suppress ovulation, but this effect is not the primary mechanism of action. Pregnancy rates with perfect and typical use ofprogestin-only OCs are similar to those with combination OCs. Progestin-only OCs are commonly prescribed when women wish to take OCs butestrogenis contraindicated. Women with current breast cancer should not take progestin-only pills, implants, or injections. Progestin-only contraceptive use represents atheoretical or proven risk that usually outweighs the advantagesin patients with the following characteristics: Past breast cancer and no evidence of current disease for 5 years Unexplained vaginal bleeding Current and history of ischemic heart disease Severe (decompensated) cirrhosis, hepatocellular adenoma, or liver cancer History of jejunal bypass surgery (for progestin-only pills) Current treatment withrifampin,rifabutin, or certain antiseizure medications (for progestin-only pills) Ischemic heart disease, severe hypertension, or multiple risk factors for atherosclerotic cardiovascular disease (for progestin contraceptive injections) Vascular disease, including due to diabetes or systematic lupus erythematosus (for progestin contraceptive injections) (For more information, see theUS Medical Eligibility Criteria for Contraceptive Use, 2016andUpdate to US Medical Eligibility Criteria for Contraceptive Use, 2016: Updated recommendations for the use of contraception among women at high risk for HIV infection.) 