[Body weight increase and quality of semen: a controversial association].

BACKGROUND Infertility is a public health disorder affecting 10% of the population worldwide. Research on the impact of body mass index (BMI) on male fertility is very limited as compared to the multiple studies evaluating the impact of overweight in women's fertility. Although 25%-30% of the cases of couples consulting for infertility are attributable to male factors, studies evaluating the association between semen parameters and BMI are controversial. OBJECTIVE To assess the impact of BMI on semen parameters in a selected group of men with unexplained infertility. METHOD A retrospective analysis of 168 patients during the 2008-2010 period. They all had at least one semen analysis and related studies to rule out known causes of infertility. Median age of patients was 35 years (22-55), and they were divided into three groups: normal weight (BMI: 20-24.9kg/m(2)), overweight (BMI 25-29.9kg/m(2)), and obese (BMI ≥30kg/m(2)). RESULTS There were no significant differences in semen parameters evaluated between the three groups, and no significant correlation was found between the same parameters and BMI. CONCLUSIONS There was no significant association between BMI and conventional semen parameters, but we cannot exclude an impairment in other semen parameters that are not routinely assessed, which could result in a lower potential fertility in these individuals.