Semen analysis with regard to sperm number, sperm morphology and functional aspects

Area of Science:

• Reproductive biology
• Andrology
• Clinical laboratory science

Background:

• The World Health Organization (WHO) manual for semen analysis is a key reference for fertility assessments.
• Previous editions have faced scrutiny regarding their evidence base for specific parameters.

Purpose of the Study:

• To critically evaluate the evidence-based foundation of the recommendations in the new WHO Manual for Semen Analysis.
• To assess the implications of revised semen analysis criteria on the field of andrology.

Main Methods:

• Review and analysis of the recommendations presented in the latest WHO Manual for Semen Analysis.
• Comparison of new criteria with previous editions and existing scientific literature.

Main Results:

• The manual updates the reference limit for sperm concentration, moving away from the 20 million spermatozoa/mL threshold.
• Recommendations for grading progressive motility and sperm morphology lack clear evidence-based justification.
• The adoption of 'Tygerberg strict criteria' for morphology is noted as potentially biased and not evidence-based.

Conclusions:

• The new WHO manual introduces some improvements but suffers from a lack of evidence-based support for critical parameters like motility and morphology.
• The current recommendations may hinder the scientific advancement of andrology due to unsubstantiated criteria.