Correlation between the times of IUI and pregnancy outcome: a systematic review and meta-analysis with trial sequential analysis of cohort study

Abstract

Abstract Purpose the study aims to evaluate whether increasing the times of IUI per cycle has better pregnancy outcomes for infertile couples. Methods PubMed, Embase, Web of science, Cochrane Library, CNKI, WanFang Data, VIP (VIP Chinese Journal Service Platform), and SinoMed (China Biomedical Literature Service), were systematically retrieved cohort studies about the times of IUI per cycle and pregnancy outcomes published before December 31, 2021. Included studies were assessed by Newcastle-Ottawa Scale (NOS) with two reviewers. The data was processed with RevMan 5.4.1 and the result of the meta-analysis were further examined by TSA 0.9.5.10 Beta version. Results 23 cohort studies with 54208 IUI cycles were included in this study. Meta-analysis of the data reported in these 23 studies showed that the cycle pregnancy rates were higher in the double insemination group (double IUI) than in the single insemination group (single IUI) [RR = 1.14, 95% CI (1.02, 1.27), I2 = 64%, P = 0.02]. Sensitivity analysis showed that the results were stable and reliable. The bias analysis showed that there was a low possibility of publication bias in this study. TSA of 23 trials illustrate that the cumulative z-curve crossed the traditional boundary, the trial sequential monitoring boundary and the required information size(RIS). Conclusion compared with single IUI, double IUI per cycle can increase the cycle pregnancy rates to a small extent without increasing the incidence of biochemical pregnancy, miscarriage, or ectopic pregnancy. The results should be treated with caution and other factors should be taken into consideration when making clinical decisions.