Effect of Immediate Compared With Delayed Insertion of Etonogestrel Implants on Medical Abortion Efficacy and Repeat Pregnancy: A Randomized Controlled Trial.

Objective: To evaluate the effect of insertion of etonogestrel implants with mifepristone compared with after the abortion on the risks of medical abortion failure and repeat pregnancy over the subsequent 6 months.

Methods: In a randomized trial, we assigned patients undergoing medical abortion to receive etonogestrel implants either with the mifepristone (Quickstart group) or after the abortion (Afterstart group). We followed them for 7 months to ascertain abortion outcome, pregnancies, and contraception use.

Results: Between September 2013 and August 2014, we enrolled 236 participants in the Quickstart group and 240 in the Afterstart group. To examine abortion failure, we conducted a noninferiority analysis from which we excluded nine participants who had missing outcome data and four with specified protocol violations. Of the rest, 9 of 229 (3.9%) and 9 of 234 (3.8%) in the Quickstart and Afterstart groups, respectively, had surgery to complete the abortion; the difference of 0.08% (90% confidence interval -3.1% to 3.3%) excluded our prestipulated noninferiority margin of 5 percentage points. Among participants with pregnancy follow-up through 6 months, 1 of 213 (0.5%) and 3 of 208 (1.4%) in the Quickstart and Afterstart groups, respectively, became pregnant within that time; 6-month pregnancy rates did not differ significantly by group (exact log-rank test, P=.28). At enrollment, significantly more participants in the Quickstart group than in the Afterstart group were satisfied with their group assignments (187/236 [79%] compared with 129/240 [54%], respectively; P<.001).

Conclusion: Insertion of etonogestrel implants with mifepristone did not appreciably increase medical abortion failure risk and it enhanced patient satisfaction, but we found no evidence that it decreased repeat pregnancy rates.

Clinical Trial Registration: ClinicalTrials.gov, www.clinicaltrials.gov, NCT01902485.