Microdose intravaginal levonorgestrel contraception: A multicentre clinical trial: III. The relationship between pregnancy rate and body weight

Abstract This paper Investigates the relationship between pregnancy rates and body weight of 1005 women using a vaginal ring releasing 20 μg levonorgestrel per 24 hours. While the overall pregnancy rate at one year was 3.7%, it was found that women have an increasing risk of pregnancy with increasing body weight. For example, a woman of 40 kg has an estimated pregnancy rate of 1.7% in contrast to 9.8% for a woman of 80 kg weight.