Mechanism of action

Teenage pregnancy is a significant public health issue. Worldwide, some 15 million pregnancies occur every year among young women aged 15 to 19, approximately 1.25 million in the 28 OECD (Organization for Economic Cooperation and Development) nations, and between 750.000 and 850.000 in the United States. As is well known, an estimated fifth of pregnancies World Wide ended in abortion. In Europe this proportion was nearer a third. Among the various measures proposed is emergency contraception, understanding as such those back up methods for contraceptive emergencies which women can back up methods for contraceptive emergencies which women can use within the first few days after unprotected sexual intercourse or in the event of potential contraceptive failure, to prevent an unwanted pregnancy. However, the morning-after pill, the active substance of which is levonorgestrel (LNG), is undoubtedly the most widely used method. In Spain alone 506.000 units were issued in 2002.