A North American study of anthropometric factors and semen quality

Objective: To evaluate the association between anthropometric measures and semen parameters.Design: Cross-sectional study. Subjects: Male participants aged >= 21 years. We analyzed data from 659 males (1185 samples) participating in a semen testing sub-study of the Pregnancy Online Study (PRESTO), a North American preconception cohort study. After enrollment, we invited males aged >= 21 years to perform at-home semen testing using the Trak system.Exposure(s): Participants reported selected anthropometric variables (current weight, height, waist circumference, and weight at age 17 years) and covariate data via an online baseline questionnaire.Main Outcome Measure(s): We used generalized estimating equations models to estimate the percent difference in mean log-transformed semen parameter values and 95% confidence intervals (CI) for associations between selected anthropometric variables and semen volume (mL), sperm concentration (million/mL), and total sperm count (million), adjusting for sociodemographics, lifestyle factors, and medical history. We also evaluated World Health Organization-defined thresholds for low semen quality.Result(s): Percentage differences in mean log-transformed semen volume, sperm concentration, and total sperm count (95% CI) comparing current body mass index >= 35 vs. <25 kg/m2 were -6.3 (-15.8, 4.3), -6.4 (-24.6, 16.2), and -12.2 (-31.1, 11.8), respectively. Percentage differences (95% CIs) comparing waist circumferences of >= 42 vs. <31 inches were -4.2 (-15.0, 8.0), -6.4 (-27.6, 21.0), and -10.4 (-31.9, 17.9) for semen volume, sperm concentration, and total sperm count, respectively. Greater adult weight gain since age 17 years was associated with reduced semen volume (>= 25 vs. <5 kg; percent difference, -9.7; 95% CI, -18.4, 0.1), but not sperm concentration or total sperm count. The highest categories of each anthropometric variable generally were associated with World Health Organization-defined low total sperm count (<= 39 million).Conclusion(s): Selected anthropometric factors were associated modestly with poorer semen quality. (Fertil Steril (R) 2023;120:586-96. (c) 2023 by American Society for Reproductive Medicine.)

Automated summary

This study evaluated the association between anthropometric measures and semen parameters, finding that selected anthropometric factors were modestly associated with poorer semen quality. Body mass index and waist circumference were found to have an impact on semen volume and sperm count.