How to choose the right contraception

What it is

There are two methods of emergency contraception that may be used after you've had unprotected intercourse or a contraceptive accident. These are the emergency contraceptive pill and the emergency fitting of a copper-containing intra-uterine contraceptive device (IUCD or coil - see entry).

How it works

The emergency contraceptive pill (Levonelle) contains high doses of a synthetic hormone, levonorgestrel, which is related to the female hormone, progesterone. It helps to prevent a fertilised egg from implanting in the womb. It will not prevent a pregnancy after a fertilised egg has already implanted.

The emergency contraceptive pill can be taken up to 72 hours after unprotected sex. It is most effective if taken as soon as possible after sex.

• Your next period may be early or late.
  
• You should use a barrier method of contraception (eg condoms) until your next period starts.
  
• You should seek prompt medical advice if you develop low abdominal pain.
  
• You should seek medical advice if your next period is abnormally light, heavy, brief or absent, or if you are concerned in any other way.
  
• You may need to consider screening for sexually transmitted infections such as chlamydia, if you have had unprotected sex.
  
• You should see your doctor three weeks after taking it, to ensure that it's worked, and to discuss a reliable method of contraception for the future.

Pros

• Emergency contraception is estimated to prevent 85% of expected pregnancies, when treatment is started within 72 hours of unprotected sex.
  
• Available on prescription, from family planning and some hospital clinics, and can also be bought over the counter from a pharmacist (as long as you're over the age of 16), though it's not cheap.

Cons

• One in 20 women develop nausea or vomiting. Taking the emergency contraceptive pill after a light meal will help to prevent nausea. Your doctor or pharmacist may also recommend an anti-sickness tablet. If vomiting occurs within two or three hours of taking a dose, a replacement dose can be given.
  
• There may be an increased risk of ectopic pregnancy.

Emergency contraception is less likely to work if you:

• have unprotected sex after you take it
  
• vomit or have severe diarrhoea without two hours of taking either dose.
  

Emergency oral contraception cannot be used if you would have to take the first dose more than three days after unprotected sex, if your period is overdue, or if you had unprotected sex earlier in your menstrual cycle.

In some cases, a copper-containing contraceptive coil can be fitted within five days of unprotected sex, as an emergency form of contraception. This works by stopping an egg being fertilised or implanting itself in the womb lining. This method is almost 100% effective, and is ideal if you also need long-term contraception, although it can be removed again when you have your next period, if you prefer.