Intrauterine insemination, what do we really know? A critical appraisal of the literature

Keywords:

cervical factor, effectiveness/intrauterine insemination, male subfertility, subfertility, unexplained sub -
fertility

P. STEURES 1, 2, 3, J. W. VAN DER STEEG 1, 2, 3, P. G. A. HOMPES 1, P. M. M. BOSSUYT 4,
B. W. J. MOL 2, 5, F. VAN DER VEEN 2

1Department of Obstetrics & Gynaecology, Vrije Universiteit Medical Centre, Amsterdam, The Netherlands.
2Centre for Reproductive Medicine, Academic Medical Centre, Amsterdam, The Netherlands.
3Department of Public Health, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands.
4Department of Biostatistics & Epidemiology, Academic Medical Centre Amsterdam, The Netherlands.
5Department of Obstetrics & Gynaecology, Máxima Medical Centre, Veldhoven, The Netherlands.

Correspondence at: pn.steures@amc.uva.nl

Abstract

Intrauterine insemination (IUI) is the first line treatment in couples with unexplained subfertility, cervical factor subfertility and male subfertility. To appraise the effectiveness of IUI for these three indications, we performed a systematic review and a comprehensive series of meta-analyses. We included Cochrane reviews and searched the literature for additional studies. Outcomes were live birth, ongoing pregnancy, clinical pregnancy and multiple pregnancy .
We were able to include 14 studies reporting on IUI for unexplained subfertility, two studies reporting on IUI for cervical factor subfertility and nine studies reporting on IUI in male subfertility.
In couples with unexplained subfertility, IUI without controlled ovarian hyperstimulation (COH) was associated with higher ongoing pregnancy rates than expectant management (relative risk (RR) 1.3, [95% CI 0.84 to 1.9]), whereas IUI with COH was more effective than IUI without COH (RR 1.8, [95% CI 1.2 to 2.7]). However, in couples with relatively good prospects for spontaneous pregnancy, there was no benefit from IUI with COH over expectant management . In  couples with a cervical factor, IUI without COH was associated with higher pregnancy rates compared to expectant management (RR 1.6, [95% CI 0.87 to 3.1]), but addition of COH did not further improve the pregnancy rates (RR 1.0, [95% CI 0.59 to 1.8]). In couples with male subfertility, IUI was more effective than expectant management, although the limited power of the included studies hampers strong conclusions. In these couples, addition of COH also had no extra benefit (RR 0.92, [95% CI 0.46 to 1.8]). Studies comparing IUI and IVF were rare, limiting assess ment of the strategy of IVF as first line treatment.
Despite the fact that IUI is one of the most frequently used treatments in reproductive medicine, our review shows that the number of studies assessing it’s effectiveness is limited and that most of these studies had small sample sizes. This results in imprecise effect estimates, as demonstrated by the non significant effects and large confidence intervals. Also, many studies did not adhere to present quality standards for design, conduct and report of clinical trials. Therefore, there is an urgent need for more RCTs in which IUI is compared to expectant management or IVF.