Normal Semen Analysis Results
A normal semen analysis for a reproductive-age male should meet or exceed the WHO reference limits: volume ≥1.4 mL, sperm concentration ≥16 million/mL, total sperm number ≥39 million per ejaculate, progressive motility ≥30%, total motility ≥42%, vitality ≥54% live, and morphologically normal forms ≥4.0%. 1
WHO Reference Values for Normal Semen Parameters
The 2024 AUA/ASRM guidelines provide the following one-sided lower reference limits (fifth centiles with 95% confidence intervals) based on analysis of 3,589 males from 12 countries across 5 continents 1:
- Semen Volume: 1.4 mL (1.3-1.5 mL) 1
- Total Sperm Number: 39 million per ejaculate (35-40 million per ejaculate) 1
- Sperm Concentration: 16 million/mL (15-18 million/mL) 1
- Progressive Motility: 30% (29-31%) 1, 2
- Total Motility (Progressive + Non-Progressive): 42% (40-43%) 1, 2
- Vitality: 54% live (50-56%) 1
- Morphologically Normal Forms: 4.0% (3.9-4.0%) 1
These reference values were derived from males with proven fertility (partners' time-to-pregnancy ≤12 months), males with unknown fertility status, and normozoospermic males 1.
Critical Context: Multiple Parameters Matter More Than Single Values
Assessing a combination of several ejaculate parameters is a better predictor of fertility success than any single parameter. 1 Studies examining multiple parameters—which more accurately reflect testicular production, function, and maturation—present odds ratios and predictive values comparable to diagnostic laboratory tools in other areas of modern clinical medicine 1. Single-parameter assessments often show discriminatory power close to chance (ROC-AUC near 0.500) 1.
Important Considerations for Interpretation
Fertile vs. Subfertile Ranges
Research demonstrates extensive overlap between fertile and infertile men even within "normal" ranges 3. Classification-and-regression-tree analysis suggests:
- Subfertile ranges: Concentration <13.5 million/mL, <32% motility, <9% normal morphology 3
- Fertile ranges: Concentration >48 million/mL, >63% motility, >12% normal morphology 3
- Intermediate/indeterminate range: Values between these thresholds 3
The percentage of sperm with normal morphology has the greatest discriminatory power among individual parameters, though none are diagnostic of infertility by themselves 3.
Single vs. Repeat Analysis
Analysis of a single ejaculate is sufficient to determine the most appropriate investigation and treatment pathway, although semen analysis should be repeated if one or more abnormalities are found. 1 This recommendation applies specifically to referral for infertility investigation and treatment 1. The "intermediate" or "borderline zone" patients benefit most from repeat analysis to confirm results or clarify severity 1.
At least two semen analyses should ideally be performed at least one month apart due to significant intra-individual variability 2, 4.
Common Pitfalls to Avoid
Collection Technique Matters
Proper collection is essential for accurate results 2:
- Abstinence period: 2-3 days of sexual abstinence before collection 2
- Transport: Maintain body temperature if collected at home 2
- Timing: Examine within one hour of collection 2
Laboratory Standardization
A primary reason for variability in semen parameters is failure of laboratories to adhere to standard WHO recommendations and failure to control for key parameters like abstinence 1. Adopting and adhering to appropriate WHO procedures mitigates most sources of variability 1.
pH and Volume Considerations
Males with normal semen pH (≥7.0) are unlikely to have complete distal genital tract obstruction. 1 Low ejaculate volume (<1.4 mL) with acidic semen (pH <7.0) suggests ejaculatory duct obstruction or congenital bilateral absence of the vas deferens 1.
Clinical Significance Beyond Fertility
Semen analysis is only part of the investigation of male fertility potential 1. A number of other attributes contribute to fertility, including medical history, surgical interventions, sexual function, cryptorchidism, scrotal infections, testosterone/anabolic usage, lifestyle factors (obesity, smoking), and physical examination findings (testicular size/consistency, varicocele, ductal structures) 1.