Abstract: 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% CI 0.46 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). 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.

Plain-language summary: We did computer searches for randomised trials of IUDs inserted right after abortion or miscarriage. We also wrote to researchers to find more studies. Trials could compare types of IUDs or times for insertion. We found 12 studies to include. Four trials randomised women to an IUD inserted right away or at a later time. One had no major difference. Three recent trials (of levonorgestrel intrauterine system or CuT380A) showed use was greater at six months for an IUD inserted right away compared to one inserted later. Another trial assigned women to the levonorgestrel IUD or Nova T; more women with the Nova T stopped use due to pregnancy. A subanalysis showed more IUDs came out when inserted right after abortion or miscarriage rather than later. Seven trials looked at inserting the IUD right away. From two large trials, the TCu 220C was better than the Lippes Loop and the Copper 7 for preventing pregnancy and staying in. The IUD was more likely to come out on its own when inserted after a mid-pregnancy abortion than after an earlier one. In other work, when the Lippes Loop had copper arms added, fewer women got pregnant and the IUD stayed in more often. Moderate level evidence shows that inserting an IUD right after an abortion or miscarriage is safe and practical. However, the IUD is more likely to come out when inserted right away rather than at a later time. Women are more likely to use an IUD at six months if they had it inserted right away compared to some weeks after the abortion or miscarriage.