How do levonorgestrel-only emergency contraceptive pills prevent pregnancy? Some considerations
Mozzanega, B.; Cosmi, E.
Gynecological Endocrinology the Official Journal of the International Society of Gynecological Endocrinology 27(6): 439-442
2011
ISSN/ISBN: 0951-3590 PMID: 20670097 DOI: 10.3109/09513590.2010.501885Document Number: 216724
Controversial opinions exist about the possible mechanisms throughout emergency contraception prevents pregnancy. Recently, the International Federation of Gynaecology and Obstetrics and the International Consortium for Emergency Contraception released a Joint Statement declaring that 'inhibition or delay of ovulation should be their primary and possibly only mechanism of action'. They still added that 'Review of the evidence suggests that LNG-ECPs cannot prevent implantation'. Concerning levonorgestrel-only emergency contraceptive pills effects on ovulation, the Statement based on seven reference papers which considered a total of only 142 patients, divided into still different subgroups. Basing on their same references we got quite different conclusions.