More sex, but young take more care

"I was freaked out the first time I used it. It was a Sunday and I didn't know where I could go to get it. In the end we went to casualty at the hospital and a doctor gave me the prescription."

Melissa is 17 and one of thousands of sexually active teenage girls who know about - and increasingly rely on - the "morning-after Pill" for emergency contraception.

Research suggests that knowledge and use of emergency contraception is growing and this may explain why, although more adolescents under 16 are having sex, the pregnancy rate is steady.

The Family Planning Association says that emergency contraception has had "a significant impact" on pregnancy rates nationally.

The study, carried out in Scotland, found that almost a third of girls claim to have had sex before their 16th birthday, and over 30 per cent say they have used the morning-after Pill. However, the researchers, who interviewed fourth-year pupils at eight state schools and two private schools in Lothian, say that if the teenage pregnancy rate is to fall further, better health education is needed to reach teenagers at the less academic schools who are more likely to be having regular sex but less likely to know about contraception.

The study, published in today's British Medical Journal, coincides with an initiative by the Health Education Authority, to be launched next week, which aims to increase awareness of emergency contraception and the fact that the "morning-after" tag is wrong. The Pill can be used up to 72 hours after unprotected intercourse, a detail that many teenagers are ignorant of, assuming that it can only be taken 24 hours after sex.

Emergency contraception consists of two pills containing high doses of the hormones progestogen and oestrogen. Another two pills are taken 12 hours after. It has a success rate of 95-to-98 per cent and in case of failure there is no evidence the developing foetus is harmed by the drug, says the FPA.

It works by delaying ovulation, or if ovulation has occurred, by delaying the journey of the egg into the womb. The drug can also change the lining of the womb so that implantation of a fertilised egg is inhibited. Toni Belfield, director of information at the FPA, says it is vital that women know that emergency contraception is not a form of early abortion. "There is a lot of confusion about this and it may put some women off. It is not an abortifacient."

For women who miss the 72-hour deadline, there is an intra-uterine device which can be inserted five days after unprotected intercourse, and has a "negligible" failure rate.