What is emergency contraception?
Emergency contraception is contraception that is used within a short time after unprotected intercourse to prevent an unwanted pregnancy. It is of two types: Hormonal and Non-Hormonal. Hormonal emergency contraception is available in the form of a progestogen-only pill containing Levonorgestrel 1500 mg (Unwanted 72, Ipill, Levonelle, etc). The other pill in use is called Ulipristal Acetate. (EllaOne)
Non-hormonal emergency contraception is available in the form of the copper intrauterine device. There are specific timings for the use of both types of emergency contraception.
With pills containing Levonorgestrel 1500 mg, it needs to be taken as soon as possible after unprotected sex and within 72 hours. The longer the gap between unprotected intercourse and taking the pill the greater the lower the success rate of prevention of an unwanted pregnancy. Success rates are 95% if taken within 24 hours to 65% at 72 hours.
Hormonal methods of emergency contraception do not give ongoing contraceptive protection. Levonorgestrel can be repeated within a cycle but Ulipristal Acetate cannot. Ulipristal acetate can be taken up to five days after unprotected intercourse with success rates over 98%. The copper IUD can be inserted within 5 days of unprotected intercourse and is over 99% successful at preventing an unwanted pregnancy. It can be used for ongoing contraception.
Does it affect periods?
Hormonal emergency contraception can cause the period to come earlier, be heavier or lighter and may be associated with abdominal cramping or pain. The copper IUD can be used for ongoing contraception. Periods may be heavier than normal and also a little more uncomfortable. Things usually settle down within a few months. If the periods are unacceptably heavy or painful this IUD can be changed and a Levonorgestrel IUD (Mirena or Eloira) inserted at the same time provided this is within 7 days of the first day of the period. Changing the IUD at any other time in the cycle risks a pregnancy because the Levonorgestrel IUD cannot be used as emergency contraception.
Can emergency contraception fail?
Yes, it can fail. Hormonal emergency contraception with Levonorgestrel 1500 mg has over 95% success at preventing a pregnancy if taken within 24 hours of unprotected intercourse.i.e. it has a 5% failure rate. This failure rate increases as the number of hours from unprotected intercourse and taking the medication increases. By 72 hours the failure rate is almost 40%. Levonorgestrel emergency contraception can be repeated in the same cycle for further episodes of unprotected intercourse. Ulipristal acetate has less than 5% failure rate if taken within 5 days of unprotected intercourse. However, it cannot be repeated within the same cycle.
How do you know if you are pregnant and it has failed?
If the period following ingestion of emergency contraception is overdue by 7 days or more a urine pregnancy test should be done preferably with an early morning sample of urine. If this is positive it indicates that the emergency contraception has failed.
How does it compare with regular contraception?
Emergency contraception is intended to be used in an emergency when regular contraception fails or there has been unprotected intercourse due to other circumstances i.e regular contraception cannot be used due to medical reasons, failure of barrier contraception or rape. There are several safe and effective options for regular contraception. A gynaecologist is qualified to discuss risks and benefits of a variety of contraceptive options and offer the most suitable one to the patient. Regular contraception avoids the stress and tension associated with not knowing if emergency contraception has worked. Generally as a rule if emergency contraception is required more than twice in a 3 month period and intercourse is likely to happen at least once a week, it is better to use regular contraception. Details about regular contraception are provided in a separate article.
What other precautions are necessary when requesting emergency contraception?
If unprotected intercourse has occurred whether due to the failure of regular contraception or because none was used, it is important to see a doctor. This is so that the risk of sexually transmitted infections can be assessed and appropriate treatment offered. Emergency treatment for HIV is available at government hospitals to prevent the infection should the risk of exposure be deemed as high. This needs to be taken within 24 hours to be most effective. Some exposures are high risk because of their nature e.g. commercial sex workers, anal intercourse in gay men, multiple sexual partners. However, most sexual histories are not as simple as they may seem and it is important that a doctor or health care worker determines the risk. Everyone is at risk unless proved otherwise.