Effect of Immediate Compared With Delayed Insertion of Etonogestrel Implants on Medical Abortion Efficacy and Repeat Pregnancy

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.