The certainty of the evidence is downgraded by imprecion (few events).
A Cochrane review «Agents for ovarian stimulation for intrauterine insemination (IUI) in ovulatory women with infertility»1 «Cantineau AE, Rutten AG, Cohlen BJ. Agents for ovarian stimulation for intrauterine insemination (IUI) in ovulatory women with infertility. Cochrane Database Syst Rev 2021;(11):CD005356. »1 included 47 studies assessing gonadotropins for intrauterine insemination. Gonadotropins versus anti-oestrogens: Gonadotropins improved live birth rate (OR 1.37, 95% CI 1.05 to 1.79; I² = 30%; 5 studies, n=1924). Gonadotropins with GnRH antagonist versus gonadotropins alone: There was no significant difference in live birth rate (OR 1.5, 95% CI 0.52 to 4.39; I² = 81%; 3 studies, n=419). Aromatase inhibitors versus gonadotropins: Aromatase inhibitors had lower live birth rate (OR 0.49, 95% CI 0.34 to 0.71; I²=0%; 2 studies, n=651). None of the agents compared lead to significantly higher multiple pregnancy rates.
A systemic review and individual participant data (IPD) meta-analysis «Wessel JA, Danhof NA, van Eekelen R, et al. Ovarian stimulation strategies for intrauterine insemination in couples with unexplained infertility: a systematic review and individual participant data me»2 included 7 RCTs with provided IPD of 2495 couples for intrauterine insemination (62.4% of the 3997 couples participating in 22 RCTs), of which 2411 had unexplained infertility and were included. Six RCTs (n=1511) compared gonadotrophins with clomiphene citrate (CC), and one (n=900) compared gonadotrophins, letrozole and CC. Moderate-certainty evidence showed that gonadotrophins increased the live birth rate compared to CC (RR 1.30, 95% CI 1.12 to 1.51; 6 RCTs, n=2058). Low-certainty evidence showed that gonadotrophins may also increase the multiple pregnancy rate compared to CC. Heterogeneity on multiple pregnancy could be explained by differences in gonadotrophin starting dose and choice of cancellation criteria. Moderate certainty evidence showed that gonadotrophins reduced the time to conception leading to a live birth when compared to CC (HR 1.37, 95% CI 1.15 to 1.63; 6 trials, n=2058).