an accidental pregnancy following unprotected sexual intercourse which may have occurred in the following circumstances:- 1. No method of birth control used, especially first time intercourse.

2. Condom breakage or accidental dislodgement.

3. A diaphragm found to be torn or removed too early.

4. An intra-uterine-device is found to be dislodged or expelled.

5. Missed contraceptive pills.

6. Sexual assault, i.e. rape or incest.

No doctor can be certain that sexual intercourse on any day of the menstrual cycle would not result in pregnancy, but in a normal 28 day cycle days 7 to 17 would be considered the danger period. The most common method of emergency contraception would be the administration of hormone tablets commonly known as "the morning after pill''.

Most often the pills used are a high dose birth control pill but there are available pills packaged specifically for this use. Two doses of pills are given 12 hours apart, however they must be give within 72 hours of intercourse in order to be effective.

Pregnancy is prevented by producing changes in the lining of the uterus which makes it unsuitable for a fertilised egg to be implanted, also there may be changes in the ovaries which prevent egg production. Bleeding will normally occur within five days of taking the second dose of pills. The most common side effects are nausea and vomiting and for this reason anti-nausea pills such as those used for travel sickness may be given at the same time.

If vomiting occurs within three hours of taking the pills the woman should contact her doctor or clinic as a further supply may be needed.

The amount of hormones given is not dangerous but it should be remembered that this is an emergency method and should not be relied on as a long-term method.

Couples in a long-term relationship will receive counselling in the different method of contraception and encouraged to accept one which may be suitable for their needs.

The failure rate of this method of emergency contraception is between one and five percent but in many cases this is thought to be due to poor recall and reporting of menstrual dates.

If pregnancy does occur after taking hormone tablets there is no evidence that the baby would be adversely affected.

The second method of emergency contraception used would be the insertion of an intra uterine device, however this method would be contra indicated if the woman had never been pregnant. This method would be especially indicated in cases where the woman has a history of blood clotting disease, liver disease or if she is taking other medications which would interact with hormones. One great advantage with this method is that the device can be inserted up to five days after unprotected intercourse and still be effective, it can then remain in place to provide contraception for up to five years.

The copper contained in the device produces the necessary changes in the lining of the uterus to again prevent implantation of a fertilised egg.

Studies in the UK show this to be a highly effective method. Only four documented failures having been reported.

Some people perceive that emergency contraception will work even if there is a possibility that pregnancy has already occurred. Where there is any doubt the doctor will order a pregnancy test and possibly perform a pelvic examination before prescribing any method of emergency contraception. In all cases the woman will be asked to return to the clinic or doctor two weeks after any method of emergency contraception has been ordered, in all cases to ensure that pregnancy has not occurred, and in the case of an intra-uterine device to make sure that it is in the correct position. Further advice and where necessary prescribing of a permanent method of contraception will be carried out at this time.

MRS BRENDA ROWSE Nursing Supervisor Health Department