Levonorgestrel emergency contraception and bodyweight

Objectives: Emergency contraception (EC) provides an opportunity to avoid an unwanted pregnancy following unprotected sexual intercourse (UPSI), failure of a regular contraceptive method, or after sexual assault. Two main methods are currently available: oral pills or the copper-T intrauterine device. In recent years there has been some debate regarding the efficacy of oral therapy in obese women. In this brief commentary we review new evidence, published after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) referral of 2014, relating to the effect of obesity on the pharmacokinetics and clinical efficacy of levonorgestrel EC in light of some of the concerns that have been raised. Methods: A PubMed literature search ("levonorgestrel" and "emergency contraception") was conducted between 1 January 2005 to 31 March 2018; results from the main clinical trials are discussed. Additional literature known to the authors and identified from the reference lists of cited publications was included. Results: Overall, it should be noted that, in studies which determined pregnancy rates across different weight or BMI categories, the overall pregnancy rate was low (1-2%) and there was no direct evidence that lower levonorgestrel plasma levels contributed to an increased pregnancy rate in obese women. This conclusion was reached by the EMA referral in 2014 and they concluded that emergency contraceptive pills (ECPs) could be taken regardless of body weight or BMI, as soon as possible after UPSI. Since the EMA review, additional evidence has been published regarding this topic. This includes PK data (which can neither support, nor deny the previously submitted meta-analyses during the Article 31 Referral procedure), or re-analyses of the previously submitted data. Conclusions: Evidence published since the EMA referral in 2014 does not change the original conclusions of the agency, which recommended that ECPs could be taken regardless of body weight or BMI, as soon as possible after UPSI.