Emergency contraception

The pills can be bought or are free of charge on prescription

There are two methods of emergency contraception - the emergency pill and the coil or intrauterine device (IUD).

The emergency pill

Emergency contraceptive pills contain the hormone progestogen. They must be taken within three days (72 hours) of unprotected sex.

Emergency pills are more effective the sooner they are taken after sex.

If taken within 24 hours, they prevent more than nine out of 10 pregnancies that would have happened had no pills been taken.

The pills work by stopping or delaying an egg being released or stopping a fertilised egg settling in the womb.

A woman taking these pills may have her next period a few days later than she would normally expect. The emergency pill will not protect her against pregnancy if she has further unprotected sex.

Emergency pills can be taken more than once, but they are not as effective as using a regular method of contraception.

Any woman over the age of 16 can buy the emergency pill from a pharmacy in the UK.

It is also available free of charge from GP surgeries and various health clinics.

Although serious side effects are rare, some women may experience headaches, breast tenderness or abdominal pain after taking the emergency contraceptive.

A few feel sick or vomit.

The IUD

IUDs are helpful if a woman is too late to take pills or if she does not want to take hormones.

These devices can be put in as late as five days after having sex, although earlier is preferable.

The IUD is the most effective method of emergency contraception, preventing 98% of pregnancies expected to occur if no emergency contraception had been used.

It must be fitted in the womb by a trained doctor or nurse. It works by stopping an egg being fertilised and stopping an egg settling in the womb.

An IUD can be removed during the woman's next period if she wishes.

There is a small risk of infection after fitting an IUD and it may not be a suitable option for some women.

There is also a small risk of ectopic pregnancy, where the baby develops outside the womb. This is uncommon but dangerous.

Therefore, it is important the woman sees a doctor or nurse three to four weeks after the IUD has been fitted to check that no pregnancy or complications have occurred.

Health professionals warn that emergency contraception should only be used in the last resort.

It is not intended as a regular form of contraception, and should only be taken extremely sparingly.

Emergency contraception also raises moral and religious issues for some people who believe it represents a form of early abortion.