PIP: Women who have had unprotected intercourse can use emergency contraception to prevent pregnancy. Emergency contraception can be a backup contraceptive method under circumstances of incorrect method use or method failure. It can also be used in cases of sexual assault. Oral contraceptives (OCs) and IUDs can be used as safe and effective postcoital contraceptive methods. Since postcoital contraception is less effective and may cause bothersome side effects (e.g., nausea), it should not be used often. Women need to know about and have access to emergency contraception. Some family planning providers do not offer emergency contraception. Many providers do not have adequate knowledge of emergency contraception. Other barriers to emergency contraceptive use are that clinics are closed at night and during the weekend when the need is highest, and the requirements for prescription. Emergency contraception protects against pregnancy by blocking ovulation, fertilization, transport of the fertilized ovum, or implantation. Combined OCs (2 doses of 100 mcg ethinyl estradiol + 0.5 mg levonorgestrel taken 12 hours apart) are the most common emergency contraceptive method. Other hormonal methods of postcoital contraception are progestin-only OCs (2 doses of 0.75 mg levonorgestrel taken 12 hours apart), estrogen (5 mg ethinyl estradiol for 5 days), a synthetic androgen (2 doses of 400-600 mg danazol taken 12 hours apart), and an antiprogestin (600 mg mifepristone [RU-486]). The combined OC, the androgen, and the antiprogestin need to be taken within 72 hours of unprotected intercourse. The progestin-only OC and the estrogen must be taken within 8 hours and 48 hours of unprotected intercourse, respectively. The IUD must be inserted within 5 days. It should be avoided in women at high risk of sexually transmitted diseases, however. When a woman seeks emergency contraception, providers should counsel her about effective, regular contraception and ask her about her plans should she become pregnant.