Predictive value of normal sperm morphology in intrauterine insemination (IUI): a structured literature review

The aim of the study was to conduct a structured review of the literature published on the use of normal sperm morphology, as an indicator of male fertility potential in intrauterine insemination (IUI) programmes. Published literature in which normal sperm morphology was used to predict pregnancy outcome in IUI during the period 1984-1998 was reviewed. In total, 421 articles were identified via Medline searches. Eighteen provided data that could be tabulated and analysed. Eight of the analysed studies provided sufficient data for statistical analysis, six studies used the Tygerberg 'strict' criteria, and two the WHO guidelines (1987, 1992). A meta-analysis of the six studies in the strict morphology group yielded a risk difference (RD) between the pregnancy rates achieved in the patients below and above the 4% strict criteria threshold of -0.07 (95% CI: -0.11 to 4.03; P<0.001). The WHO criteria group (1987, 1992) had insufficient data to be analysed. Meta-analysis showed a significant improvement in pregnancy rate above 4% threshold for strict criteria. Accurate evaluation of normal sperm morphology results should be an integral part of evaluating the male factor.