Emergency Contraception: How Does the Morning After Pill Work?
Emergency contraception, or post-coital contraception, refers to methods of contraception that can be used to prevent pregnancy in the first few days after intercourse. It is intended for emergency use following unprotected intercourse, contraceptive failure or misuse (such as forgotten pills or torn condoms), rape or coerced sex.
Emergency contraception is effective only in the first few days following intercourse before the ovum is released from the ovary and before the sperm fertilizes the ovum. Emergency contraceptive pills cannot interrupt an established pregnancy or harm a developing embryo.
Methods of emergency contraception:
1. Emergency contraception pills: WHO recommends levonorgestrel for emergency contraceptive pill use. Ideally, this progestogen-only method should be taken as a single dose (1.5 mg) within five days (120 hours) of unprotected intercourse. Alternatively, a woman can take the levonorgestrel in two doses (0.75 mg each; 12 hours apart).
2. Copper-bearing intrauterine devices (IUDs): WHO recommends that a copper-bearing IUD, as an emergency contraceptive, be inserted within five days of unprotected intercourse. This may be an ideal emergency contraceptive for a woman who is hoping for an ongoing, highly effective contraceptive method.