Immediate versus delayed postabortal insertion of contraceptive implant

Background: Contraceptive implants are one of the most effective contraceptive methods, providing a long duration of pregnancy protection and a high safety profile. Hence this method is suitable for optimizing the interpregnancy interval, especially for women undergoing abortion. Women who have had abortions are at high risk of rapid repeat pregnancies. Provision of effective contraception at the time of an abortion visit can be a key strategy to increase access and uptake of contraception. A review of the evidence was needed to evaluate progestin-releasing implants for immediate use at the time of abortion, including whether immediate placement impacts the effectiveness of medical abortion, which relies on antiprogestogens.

Objectives: To compare contraceptive implant initiation rates, contraceptive effectiveness, and adverse outcomes associated with immediate versus delayed insertion of contraceptive implants following abortion.

Search methods: We searched for all relevant studies regardless of language or publication status up to September 2019, with an update search in March 2021. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Ovid EBM Reviews), MEDLINE ALL (Ovid), Embase.com, CINAHL (EBSCOhost) (Cumulative Index to Nursing and Allied Health Literature), Global Health (Ovid), LILACS (Latin American and Caribbean Health Science Information database), Scopus, ClinicalTrials.gov, and the WHO ICTRP. We examined the reference lists of pertinent articles to identify other studies.

Selection criteria: We sought randomized controlled trials (RCTs) comparing immediate versus delayed insertion of contraceptive implant for contraception following abortion.

Data collection and analysis: We followed the standard procedures recommended by Cochrane. To identify potentially relevant studies, two review authors (JS, LS) independently screened the titles, abstracts, and full texts of the search results, assessed trials for risk of bias, and extracted data. We computed the risk ratio (RR) with 95% confidence intervals (CIs) for binary outcomes, and the mean difference (MD) with 95% CIs for continuous variables.

Main results: We found three RCTs including a total of 1162 women. Our GRADE assessment of the overall certainty of the evidence ranged from moderate to very low, downgraded for risk of bias, inconsistency, and imprecision. Utilization rate at six months may be slightly higher for immediate compared with delayed insertion (RR 1.10, 95% CI 1.05 to 1.15; 3 RCTs; 1103 women; I² = 62%; low certainty evidence). Unintended pregnancy within six months after abortion was probably lower with immediate insertion compared with delayed insertion (RR 0.25, 95% CI 0.08 to 0.77; 3 RCTs; 1029 women; I² = 0%; moderate certainty evidence). Immediate insertion of contraceptive implants probably improves the initiation rate compared to delayed insertion following medical abortion (RR 1.26 for medical abortion, 95% CI 1.21 to 1.32; 2 RCTs; 1014 women; I² = 89%; moderate certainty evidence) and may also improve initiation following surgical abortion (RR 2.32 for surgical abortion, 95% CI 1.79 to 3.01; 1 RCT; 148 women; I² = not applicable; low certainty evidence). We did not pool results for the implant initiation outcome over both abortion types because of very high statistical heterogeneity. For medical termination of pregnancy, we found there is probably little or no difference between immediate and delayed insertion in overall failure of medical abortion (RR 1.18, 95% CI 0.58 to 2.40; 2 RCTs; 1001 women; I² = 68%;moderate certainty evidence). There may be no difference between immediate and delayed insertion on rates of abnormal bleeding at one month after abortion (RR 1.00, 95% CI 0.88 to 1.14; 1 RCT; 462 women; I² = not applicable; low certainty evidence).

Authors' conclusions: Provision of progestin-releasing implants concurrently with abortifacient agents likely has little or no negative impact on overall failure rate of medical abortion. Immediate insertion probably improves the initiation rate of contraceptive implant, as well as unintended pregnancy rate within six months after abortion, compared to delayed insertion. There may be no difference between immediate and delayed insertion approaches in bleeding adverse effects at one month after abortion.