[Methodology in infertility studies. Outcome measures for therapeutic success. When should we consider that has been a change in semen quality?]. / Características metodológicas de los estudios de infertilidad. Parámetros de éxito terapeútico. Cuándo considerar que ha habido un cambio en la calidad seminal de un varón?

OBJECTIVES: Surgery has been largely indicated for varicocele with the aim of improving semen parameters in male patients with subfertility or infertility. However, the criteria for therapeutic success in which its usefulness has been based on have never been clear. Our objective was to analyze current criteria for therapeutic success after surgical treatment of varicocele, studying in depth the possible influence of varicocele on semen quality, its impact on fertility, and possible advantages of treatment. METHODS: We reviewed a group of original articles, systematic reviews, and metanalysis on the issue after MEDLINE search. We mainly focus on randomized placebo-controlled prospective studies the aim of which was to evaluate the improvement in semen quality and/or pregnancy rates in subfertile/infertile couples after treatment of varicocele. CONCLUSIONS: There is great study heterogeneity, both in methods and possible interpretation of results. Although it seems treatment of varicocele may improve some semen quality parameters, it does not seem to represent an effective treatment for male subfertility.