FSH treatment of male idiopathic infertility improves pregnancy rate: a meta-analysis

INTRODUCTION: The aim of this study is to comprehensively evaluate whether FSH administration to the male partner of infertile couples improves pregnancy rate, spontaneously and/or after assisted reproductive techniques (ART). METHODS: Meta-analysis of controlled clinical trials in which FSH was administered for male idiopathic infertility, compared with placebo or no treatment. Randomization was not considered as an inclusion criterion. RESULTS: We found 15 controlled clinical studies (614 men treated with FSH and 661 treated with placebo or untreated). Concerning the type of FSH, eight studies used recombinant FSH, whereas seven studies used purified FSH. Nine studies evaluated spontaneous pregnancy rate, resulting in an overall odds ratio (OR) of about 4.5 (CI: 2.17-9.33). Eight studies evaluated pregnancy rate after ART, showing a significant OR of 1.60 (CI: 1.08-2.37). Sub-dividing studies according to the FSH preparations (purified/recombinant), pregnancy rate improvement remained significant for each preparation. Eleven studies considered sperm quality after FSH treatment, finding a significant improvement of sperm concentration (2.66×10(6)/ml, CI: 0.47-4.84), but not of concentration of sperm with progressive motility (1.22×10(6)/ml, CI: -0.07 to 2.52). Three trials evaluated testicular volume, showing a non-significant increase in men treated (1.35 ml, CI: -0.44 to 3.14). CONCLUSION: The results of controlled clinical trials available in the literature indicate an improvement of pregnancy rate after FSH administration to the male partner of infertile couples, both spontaneously and after ART. However, the heterogeneity of studies, the high risk of bias and the lack of precise criteria to guide FSH administration limit the strength of these results. Future studies should be designed to identify the markers of FSH response which are helpful in the decision-making process. Meanwhile, the use of FSH in the treatment of male infertility should be cautious.