RESUMEN
PURPOSE: To evaluate the relationship between regional geography and sperm parameters in a cohort of American men using at-home mail-in semen collection kits with no previous self-reported history of male factor infertility. MATERIALS AND METHODS: In this study, 5,822 men from six different regions of the United States (Northeast, Southeast, Midwest, West, Pacific, and Southwest) who self-requested semen analysis between 2019 and 2021 were enrolled. RESULTS: Across the entire cohort, the mean sperm concentration was 43.79±55.43 ×106 sperm/mL; total sperm count 138.93±149.96 ×106 sperm/mL; total motile sperm 54.73±81.90 ×106/ejaculate; total motility 30.18%±22.87%; progressive motility 21.61%±17.32%; sperm with normal morphology 8.79%±8.87%. Patients from the West region displayed lower median sperm concentration, total motile sperm, and total motility than men from the other four regional areas. A lower median total sperm count, and lower median progressive motility were also detected among patients in the Southwest region. Conversely, higher results were detected in patients from the Midwest (higher median total motile sperm, total and motility) and from the Northeast (higher median sperm concentration and total sperm count) regions. Men from the Southeast (OR, 1.3168; 95% CI, 1.1142-1.5563) and Southwest (OR, 1.3145; 95% CI, 1.0735-1.6096) regions were more likely to have oligozoospermia than those living elsewhere. CONCLUSIONS: This study provides the most comprehensive and up-to-date report on semen parameter variability among a cohort of men living in six different regions of the continental USA. This study will pave the way into a deeper discussion of the interplay between geography, social determinants of fertility care and semen quality.
RESUMEN
BACKGROUND: Despite the generally accepted World Health Organization guidelines on semen analysis, an individual's results can display significant variation when performed across time or in different laboratories. Semen parameters are in fact highly variable measures that can differ significantly between various analyses. Numerous researchers have discovered a wide range of semen parameters within each individual male, but only a few studies included the analysis of semen parameters variability in patients with infertility. The aim of this study was to evaluate the inter- and intra-individual variability of semen parameters in men of reproductive age with normozoospermia and those with oligozoospermia. METHODS: Five hundred and thirteen who provided ≥ 2 semen samples (798 samples in total) using an at-home mail-in kit over a period of about 2 years were enrolled in the study. Semen samples collection using Give Legacy at-home mail-in semen collection kit; semen analysis at a CLIA-certified laboratory. RESULTS: The degree of intra-subject variation across all semen parameters was lower in men with normozoospermia compared to men with oligozoospermia. Men with normozoospermia furthermore demonstrated a level of intra-subject variation that was lower than inter-subject variation across all measured parameters. No association was observed between intra-subject coefficients of variation in any of the semen parameters, including sperm concentration, sperm count, motile sperm count, total motility, progressive motility, the percentage of sperm with normal morphology, and the age, duration of abstinence, and BMI of the men. CONCLUSION: The results of this observational study confirm the significant variability in semen parameters in men with normozoospermia and oligozoospermia, as measured from at-home semen collection kit samples. This further underscore the importance of securing multiple samples for analysis to provide a robust assessment of male fertility.