No abstract

Swedish Research Council (K2010-54X-14212-09-3) and support provided through the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and Karolinska University Hospital.

This review will focus on the available methods for emergency contraception (EC), efficacy, side effects and mechanisms of action. Copper intrauterine device (IUD) has been shown to be the most effective method for EC which can be continually used for regular contraception. However, this possibility is seldom used and may be little known. Among the hormonal EC methods 1.5 mg levonorgestrel is the most widely used EC pill while the more recently developed Ulipristal acetate (UPA) has been shown to be the most effective option. This is probably due to a more pronounced prevention of follicular rupture compared with other hormonal EC methods. Knowledge is needed to better advise lactating women and obese women on optimal EC method. Furthermore a possible interaction of UPA with regular hormonal contraception and possibilities for "bridging" from EC to regular contraception needs to be explored. To increase efficacy future studies should focus on EC methods that target the endometrium.