Across different weight and body mass index (BMI) categories, pregnancy rates with use of levonorgestrel (LNG) 1.5 mg for emergency contraception (EC) were low, a recent study found. The study of 6,873 women from 4 WHO-HRP randomized trials on EC conducted between 1993 and 2010 also showed an increase in pregnancy rates among obese women compared to women with normal BMI levels, in pooled analysis. Other findings:
- Overall pregnancy rate was 1.2%.
- Pregnancy rates were low in women over 80 kg (0.7%) and who were obese (2.0%).
- BMI >30 kg/m2 decreased efficacy significantly (OR 8.27) compared to women in lower BMI categories.
The authors concluded that LNG as EC should be promoted to women who need them, and should not be restricted in any weight or BMI category.
Festin MPR, Peregoudov A, Seuc A, Kiarie J, Temmerman M. Effect of BMI and body weight on pregnancy rates with LNG as emergency contraception: Analysis of four WHO HRP studies. [Published online ahead of print August 12, 2016]. Contraception. doi:10.1016/j.contraception.2016.08.001.