Society of Family Planning Clinical Recommendation: Emergency contraception.

Emergency contraception (EC) refers to several contraceptive options that can be used within a few days after unprotected or under protected intercourse or sexual assault to reduce the risk of pregnancy. Current EC options available in the United States include the copper intrauterine device (IUD), levonorgestrel (LNG) 52 mg IUD, oral LNG (such as Plan B One-Step, My Way, Take Action), and oral ulipristal acetate (UPA) (ella). These clinical recommendations review the indications, effectiveness, safety, and side effects of emergency contraceptive methods; considerations for the use of EC by specific patient populations and in specific clinical circumstances and current barriers to emergency contraceptive access. Further research is needed to evaluate the effectiveness of LNG IUDs for emergency contraceptive use; address the effects of repeated use of UPA at different times in the same menstrual cycle; assess the impact on ovulation of initiating or reinitiating different regimens of regular hormonal contraception following UPA use; and elucidate effective emergency contraceptive pill options by body mass indices or weight.