One-year pregnancy and continuation rates after placement of levonorgestrel or copper intrauterine devices for emergency contraception: a randomized controlled trial

Abstract

Recent evidence demonstrates the effectiveness of the levonorgestrel 52-mg intrauterine device for emergency contraception vs the copper T380A intrauterine device. Of note, 1-year pregnancy and continuation rates after intrauterine device placement for emergency contraception remain understudied. This study compared 1-year pregnancy and intrauterine device continuation rates and reasons for discontinuation among emergency contraception users randomized to the levonorgestrel 52-mg intrauterine device or the copper intrauterine device. This participant-masked, randomized noninferiority trial recruited emergency contraception individuals desiring an intrauterine device from 6 Utah family planning clinics between August 2016 and December 2019. Participants were randomized 1:1 to the levonorgestrel 52-mg intrauterine device group or the copper T380A intrauterine device group. Treatment allocation was revealed to participants at the 1-month follow-up. Trained personnel followed up the participants by phone, text, or e-mail at 5 time points in 1 year and reviewed electronic health records for pregnancy and intrauterine device continuation outcomes for both confirmation and nonresponders. We assessed the reasons for the discontinuation and used Cox proportional-hazard models, Kaplan-Meier estimates, and log-rank tests to assess differences in the continuation and pregnancy rates between the groups. The levonorgestrel and copper intrauterine device groups included 327 and 328 participants, respectively, receiving the respective interventions. By intention-to-treat analysis at 1 year, the pregnancy rates were similar between intrauterine device types (2.8% [9/327] in levonorgestrel 52-mg intrauterine device vs 3.0% [10/328] in copper intrauterine device; risk ratio, 0.9; 95% confidence interval, 0.4-2.2; P=.82). Most pregnancies occurred in participants after intrauterine device removal, with only 1 device failure in each group. Of note, 1-year continuation rates did not differ between groups with 204 of 327 levonorgestrel 52-mg intrauterine device users (62.4%) and 183 of 328 copper T380A intrauterine device users (55.8%) continuing intrauterine device use at 1 year (risk ratio, 1.1; 95% confidence interval, 1.0-1.2; P=.09). There were differences concerning the reasons for discontinuation between intrauterine device types, with more bleeding and cramping cited among copper intrauterine device users. The pregnancy rates were low and similar between intrauterine device types. Of note, 6 of 10 intrauterine device emergency contraception users continued use at 1 year. Moreover, 1-year continuation rates were similar between intrauterine device types.