Weight Loss as Therapeutic Option to Restore Fertility in Obese Men: A Meta-Analytic Study

Purpose: Weight loss has been shown to significantly elevate testosterone serum levels, though the impact on semen analysis parameters and fertility remains incompletely understood. The objective of this study was to examine the influence of body weight loss on semen parameters in obese men. Materials and Methods: A meta-analysis was performed that included clinical trials in which a semen analysis before and after weight loss was evaluated. All strategies potentially available for weight loss were considered eligible. The primary outcome was the comparison of conventional semen analysis parameters before and after weight loss. Results: Twelve studies were considered including 345 subjects (mean age 37.6 +/- 7.9 years; mean baseline body mass index 45.4 +/- 6.0 kg/m(2)). Weight loss resulted in a significant increase of sperm concentration (effect size 0.495, standard error 0.251 [0.003, 0.986], p=0.049) and progressive motility (effect size 0.567, standard error 0.372 [0.370, 0.764], p<0.001). Moreover, a significant decrease of sperm DNA fragmentation index after weight loss (effect size -0.689, standard error 0.278 [-1.123, -0.255], p=0.002) was observed. Conclusions: This meta-analytic analysis confirmed that body weight loss may improve qualitative and quantitative sperm characteristics providing evidence for suggesting weight loss to male partners with obesity and semen analysis alteration in couples attempting conception.