From the Guidelines
A semen analysis is considered normal when it shows a sperm concentration of at least 16 million per milliliter, total sperm count of at least 39 million per ejaculate, progressive motility of at least 30%, and normal morphology of at least 4%. The interpretation of a semen analysis is crucial in evaluating male fertility, and it is essential to understand the different parameters and their reference limits. According to the most recent guidelines, a semen analysis should include an evaluation of semen volume, sperm concentration, total sperm number, vitality, progressive motility, total motility, and morphologically normal forms 1.
Semen Analysis Parameters
The following parameters are evaluated in a semen analysis:
- Semen volume: 1.4 mL or more
- Total sperm number: 39 million per ejaculate or more
- Sperm concentration: 16 million/mL or more
- Vitality: 54% live or more
- Progressive motility: 30% or more
- Total motility: 42% or more
- Morphologically normal forms: 4.0% or more
Abnormal Semen Analysis Results
If the results of a semen analysis are abnormal, it may indicate potential fertility issues. Abnormal results should be confirmed with a repeat analysis after 2-3 months before making definitive conclusions about fertility potential. For mild abnormalities, lifestyle modifications are often recommended first, including avoiding tobacco, alcohol, recreational drugs, and excessive heat to the testicles. Nutritional supplements containing zinc, selenium, folate, and antioxidants like CoQ10 and vitamin C may help improve sperm parameters over 2-3 months 1.
Further Evaluation and Treatment
For more significant abnormalities, medical evaluation by a urologist or reproductive endocrinologist is necessary to identify underlying causes such as varicocele, hormonal imbalances, or genetic factors. Treatment options might include varicocele repair, hormone therapy, or assisted reproductive technologies depending on the specific issue. A full evaluation by an urologist or other specialist in male reproduction should be carried out if the initial screening evaluation demonstrates an abnormal physical exam, an abnormal male reproductive or sexual history, or an abnormal semen analysis is found 1.
From the Research
Interpretation of Semen Analysis
The interpretation of semen analysis is a complex process that involves evaluating various parameters to assess male fertility. According to 2, 3, semen analysis is the cornerstone of infertility evaluation, providing information on the functional status of the seminiferous tubules, epididymis, and accessory sex glands.
Limitations of Semen Analysis
There are several limitations to consider when interpreting semen analysis results, including:
- Lack of consideration of the female factor 2
- Vaguely defined threshold values 2
- Intra-individual variation in semen parameters 2
- Limitations of using a single threshold value to distinguish 'abnormal' and 'normal' parameters 2, 3
World Health Organization (WHO) Reference Values
The WHO has published reference values for semen analysis, with the latest edition being the sixth edition manual 4. The reference values have changed over time, with the 2010 edition introducing lower cut-off values compared to the 1999 edition 5, 6. This change has resulted in some men being reclassified from abnormal to normal 5.
Clinical Relevance
Physicians should exercise caution when interpreting semen analysis results due to the limitations of the test 3. A comprehensive evaluation of male infertility should include a physical examination, history taking, and relevant endocrine, genetic, and other investigations, in addition to semen analysis 3. The use of a template for semen analysis reports that incorporates the distribution of semen characteristics of recent fathers in centiles rather than solely the minimum thresholds may aid clinicians in better understanding how a given patient's results compare with the reference population 3.
Key Parameters
Key parameters evaluated in semen analysis include: