Effect of paternal overweight or obesity on semen parameters, clinical pregnancy and live birth outcomes in men treated with intrauterine insemination (IUI).

Background: Overweight and obese individuals are steadily increasing in recent years. Male overweight or obesity has adverse impact on reproductive functions. The study aimed to evaluate the potential impact of paternal overweight or obesity on sperm quality and clinical pregnancy outcome in patients undergoing intrauterine insemination (IUI) treatment.

Methods: This retrospective study included 1,036 couples from our reproductive center between July 2019 and August 2022. All males were categorized into normal weight, overweight, or obese groups according to their body mass index (BMI). Baseline characteristics and reproductive hormones were analyzed. Semen parameters, clinical pregnancy and live birth outcomes were compared among the different BMI groups.

Results: There were no significant differences in sperm concentration, total sperm motility, progressive sperm motility, normal sperm morphology and sperm DNA fragmentation index (DFI) among the three groups. However, the obese group exhibited a significantly decreased semen volume compared to the other two groups (P<0.01). No differences were found in clinical pregnancy rate (CPR), abortion rate (AR) and live birth rate (LBR) among the groups (P>0.05). Slight higher ARs were observed in overweight and obese groups compared to normal group (13.64%, 21.05% vs. 11.11%, P=0.49).

Conclusions: These data suggest that male obesity leads to a significant decrease in semen volume. It is thus recommended that male BMI should be regarded as one of the predictors for IUI treatment to avoid a decrease in semen volume.