Background The use of an effective contraceptive may be necessary after an abortion. Insertion of an intrauterine device (IUD) may be done the same day or later. Immediate IUD insertion is an option since the woman is not pregnant, pain of insertion is less because the cervical os is open, and her motivation to use contraception may be high. However, insertion of an IUD immediately after a pregnancy ends carries risks, such as spontaneous expulsion.Objectives To assess the safety and efficacy of IUD insertion immediately after spontaneous or induced abortion.Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, POPLINE, ClinicalTrials.gov,and ICTRP in January 27, 2014. We also contacted investigators to identify other trials.Selection criteria We sought all randomised controlled trials (RCTs) with at least one treatment arm that involved IUD insertion immediately after an induced abortion or after curettage for spontaneous abortion.Data collection and analysis We evaluated the methodological quality of each report and abstracted the data. We focused on discontinuation rates for accidental pregnancy, perforation, expulsion, and pelvic inflammatory disease.We computed the weighted average of the rate ratios.We compute drisk ratios (RRs) with 95% Confidence Intervals (CIs).We performed an intention-to-treat (ITT) analysis by including all randomised participants in the analysis according to the Cochrane Handbook for Systematic Reviews of Interventions.Main results We identified 12 trials most of which are of moderate risk of bias involving 7,119 participants which described random assignment.Five trials randomised to either immediate or delayed insertion of IUD. One of them randomised to immediate versus delayed insertion of Copper 7 showed immediate insertion of the Copper 7 was associated with a higher risk of expulsion than was delayed insertion(RR 11.98, 95% CI 1.61 to 89.35,1 study, 259 participants); the quality of evidence was moderate. Moderate quality of evidence also suggests that use and expulsion of levonorgestrel-releasing intrauterine system or CuT380A was more likely for immediate compared to delayed insertion risk ratio (RR) 1.40 (95% CI 1.24 to 1.58; 3 studies; 878 participants) and RR 2.64 ( 95% CI 1.16 to 6.00; 3 studies; 878 participants) respectively. Another trial randomised to the levonorgestrel IUD or Nova T showed discontinuation rates due to pregnancy were likely to be higher for women in the Nova T group. (MD 8.70, 95% CI 3.92 to 13.48;1 study; 438 participants);moderate quality evidence.Seven trials examined immediate insertion of IUD only. From meta-analysis of two multicentre trials, pregnancy was less likely for the TCu 220C versus the Lippes Loop (RR 0.43, 95% CI 0.24 to 0.75; 2 studies; 2257 participants ) as was expulsion (RR 0.61, 95% CI0.46 to 0.81; 2 studies; 2257 participants). Estimates for the TCu 220 versus the Copper 7 were RR 0.42 ( 95% CI 0.23 to 0.77; 2 studies, 2,274 participants) and RR 0.68, (95% CI 0.51 to 0.91); 2 studies, 2,274 participants), respectively. In other work, adding copper sleeves to the Lippes Loop improved efficacy (RR 3.40, 95% CI 1.28 to 9.04, 1 study, 400 participants) and reduced expulsion(RR 3.00, 95% CI 1.51 to 5.97; 1 study, 400 participants).Authors' conclusions Moderate quality evidence shows that insertion of an IUD immediately after abortion is safe and practical. IUD expulsion rates appear higher immediately after abortions compared to delayed insertions. However, at six months postabortion, IUD use is higher following immediate insertion compared to delayed insertion.