Does Weight Loss improve Fertility with respect to Semen Parameters— Results from a Large Cohort Study

Objective: To determine whether weight loss in obese men improves seminal parameters. Design: Prospective interventional study. Setting: Infertility clinic and weight loss centers. Patient: All men attending infertility center and weight loss programmes from April 2012 to May 2015 (n = 105). Intervention: Diet counseling and exercise. Main Outcome Measure: Collected reproductive parameters included semen analysis (ejaculate volume, sperm concentration, progressive and non-progressive motility) data. Body mass index (BMI) was calculated for all patients with comparisons to reproductive parameters before and after weight loss by using paired-t test and Chi-square tests. Result: The mean BMI was significantly higher before weight loss (33.2) than after weight loss (30.4) in obese men. The weight loss had significant positive correlation with percentage of progressive sperm motility (p = < 0.001) and static percentage (p = < 0.001). Weight loss had non-significant correlation with semen volume (p = 0.083), concentration (p = 0.418) and non progressive motile sperm (p = 0.361). Conclusion: In one of the largest cohorts of male fertility and obesity, semen parameters demonstrated mild but significant relationships with BMI and semen parameters, possibly contributing to subfertility in this population.