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

Abstract

Background: 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.

Objective: 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.

Study design: 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.

Results: 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.

Conclusion: 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.

Trial registration: ClinicalTrials.gov NCT02175030.

Keywords: emergency contraception; intrauterine device.