The Association Between Paternal BMI and Semen Quality in Cohorts Undergoing IUI, IVF and ICSI Fertility Treatments: A Systematic Review and Meta-Analysis.

In 30 seconds

This systematic review and meta-analysis examined associations between paternal BMI and semen quality in cohorts undergoing intrauterine insemination or assisted reproductive technology. Twenty-two of 34 included studies contributed to the meta-analysis; interventional studies were excluded. Overweight, compared with normal BMI, was associated with lower sperm total motility, with a pooled mean difference of -8.17 (95% CI = -15.15 to -1.20). The review found no significant association between paternal obesity and semen parameters overall. Subgroup analysis by BMI classification also identified differences in sperm concentration between overweight and normal groups.

Key findings

• Overweight versus normal BMI was associated with lower sperm total motility: pooled mean difference -8.17 (95% CI = -15.15 to -1.20).
• Paternal obesity showed no significant association with semen parameters.
• Subgroup analysis found differences in sperm concentration between overweight and normal BMI groups (test for subgroup differences, p = 0.0206).
• Across the included cohorts, paternal obesity prevalence was 12.15% and overweight prevalence was 43.37%.

Why it matters

Semen quality is considered when guiding fertility treatment, and this synthesis suggests that BMI category may relate to particular semen parameters in IUI and ART cohorts. The findings distinguish overweight from obesity: the reported motility association was for overweight, while obesity was not significantly associated with semen parameters. This may help frame counselling and assessment while highlighting uncertainty in the evidence.

What to keep in mind

The review included observational studies and excluded interventional studies; the authors note that metabolic and lifestyle factors may need to be ruled out in further research.