Emergency Contraception: How to Prevent an Unplanned Pregnancy

This article describes the modern methods of contraception used to prevent a pregnancy after unprotected sex. Emergency contraception means methods that can be used after sexual intercourse. They are needed after unplanned unprotected sex, or when the contraception being used has failed (for example, a condom breaking or forgetting to take the contraceptive pill). Emergency contraception should never be used as an everyday method of contraception.

Two such methods are currently available in Sri Lanka.

1. Emergency contraceptive pills

In Sri Lanka, emergency contraceptive pills are currently sold under the brand name Postinor, and most pharmacies stock them. They contain a medicine called levonorgestrel and are available either as two pills or as a single pill. A pill contains about ten times the amount of levonorgestrel in an ordinary contraceptive pill.

Taking 1.5 mg of levonorgestrel (one Postinor-1 pill, or both Postinor-2 pills at the same time) within 96 hours of intercourse can be used as emergency contraception. Its effectiveness is between 52% and 94%: on average it prevents about 80% of pregnancies. It works better the sooner it is taken.

The medicine works by stopping the ovaries from releasing an egg. It is also thought to make it harder for sperm to pass through the cervix and to make the womb less suitable for an embryo to settle in. According to the latest medical evidence, however, it works only if taken before ovulation. For that reason, taking these pills during the last 14 days of the menstrual cycle cannot prevent a pregnancy.

This medicine does not cause an abortion, so it has no effect once an embryo has implanted.

Side effects can include nausea, vomiting and irregular periods. If you vomit within two hours of taking the medicine, take the same dose again. If your period is more than 7 days late, do a urine test to check whether you are pregnant. The situations in which levonorgestrel emergency pills fail are explained in a separate article.

2. Intrauterine device (the loop)

This is a small device that a doctor places inside the womb through the cervix. It stops an embryo from settling in the womb. Having one fitted within 5 days of unprotected sex can prevent an unwanted pregnancy. It is more reliable than the hormone pills: it prevents about 99% of pregnancies. An added advantage is that, if you wish, it can stay in place as your method of contraception for up to 10 years.

3. A high dose of ordinary contraceptive pills (the Yuzpe method)

Taking 4 ordinary contraceptive pills such as Mithuri at once, followed by another 4 pills 12 hours later, was recommended in the past as a way to prevent pregnancy in an emergency, but this method is no longer recommended.

Using emergency contraception wisely

Taking emergency contraceptive pills often is not advisable. They contain a very high dose of hormones, so side effects are more likely. Emergency contraceptive pills also cannot prevent pregnancy 100%. Other methods of contraception are more reliable as well as safer. Talk to a doctor to choose a method of contraception that suits you.