Analysis of semen parameters in male referrals: impact of reference limits, stratification by fertility categories, predictors of change, and comparison of normal semen parameters in subfertile couples

Objective: To [1] determine the impact of semen reference limits on referrals for male fertility evaluations, [2] analyze the stratification of subjects based on published "normal" thresholds, [3] analyze the odds of changing fertility categories during serial tests and thereby the potential impact of inherent variability of semen parameters on referrals, and [4] determine variable(s) predictive of change. Design: Retrospective chart review. Setting: Academic referral center for male fertility. Patient(s): New encounters in a male fertility clinic over a 5-year period that straddles the publication of World Health Organization (WHO) 2010 reference values. Intervention(s): None. Main Outcome Measure(s): Demographic and clinical variables, semen values, and fertility categories as follows: BE (below WHO 2010 criteria), BTWN (above WHO 2010 but below WHO 1999 criteria), and N (above WHO 1999 criteria). Result(s): A total of 82.3% of initial semen tests were categorized as BE, and the predominance of this category was unchanged by publication of the WHO 2010 criteria. Men with initial semen analysis categorized as BTWN or N represented 16.2% and 1.5% of the referral population, respectively. Subjects initially categorized as BTWN were more likely to change fertility categories, and overwhelmingly this migration was downward. Analysis of normal individual semen parameters revealed statistically worse mean concentration and motility when at least one other parameter fell below the WHO 2010 criteria. Conclusion(s): Men with semen results above reference criteria are underrepresented, indicating that reference limits influence referral patterns for male fertility evaluations. Normal mean concentration and motility were lower in men with at least one other individual semen parameter below the 2010 criteria, suggesting global dysfunction in spermatogenesis. (C) 2015 by American Society for Reproductive Medicine.