The Effectiveness of Ovulation Induction and Intrauterine Insemination in the Treatment of Persistent Infertility: a Meta-analysis

A systematic review was conducted to evaluate the effectiveness of intrauterine insemination (IUI) with or without ovarian stimulation using gonadotrophin in the treatment of persistent infertility. Relevant randomized controlled trials were identified by a diverse strategy including a hand search of 43 core journals from 1966 to the present. Two approaches to meta-analysis were used to summarize data. First, using a standard Mantel-Haenszel approach, eight trials comparing FSH/IUI with FSH/timed intercourse for unexplained infertility were combined. The common odds ratio for pregnancy was 2.37 [95% confidence interval (CI), 1.43, 3.90], suggesting a significant improvement with IUI following ovulation induction in this patient group. Although the data were statistically homogeneous, clinically important heterogeneity was present. Second, across all diagnostic groups, the independent effects of treatment with follicle stimulating hormone (FSH), clomiphene citrate, IUI, as well as the diagnoses of male factor and endometriosis were assessed using stepwise logistic regression. Based on 5214 cycles reported in 22 trials, the odds ratio for pregnancy associated with FSH use was 2.35 (95% CI, 1.87, 2.94) for IUI, 2.82 (95% CI, 2.18, 3.66) for male factor, 0.48 (95% CI, 0.37, 0.61), and for endometriosis 0.45 (95% CI, 0.27, 0.76). This summary of the best available evidence may prove useful in counselling couples who are considering FSH and/or IUI therapy.