Objective semen analysis: has the target been reached?

Area of Science:

• Andrology and reproductive medicine
• Biomedical engineering
• Laboratory diagnostics

Background:

• Objective assessment of sperm concentration, motility, and morphology is crucial for male fertility evaluation.
• Existing automated and semi-automated methods face challenges including imprecision, technical complexity, and unreliability due to artefacts.
• Manual microscopic evaluation, while fundamental, is labor-intensive and requires significant technician expertise.

Purpose of the Study:

• To review the limitations of current sperm assessment technologies.
• To identify sources of error in semen analysis procedures.
• To discuss the scientific basis for inaccuracies in sperm characteristic evaluation.

Main Methods:

• Critical review of existing sperm analysis systems (physical principles, image analysis, computer-assisted semen analysis - CASA).
• Analysis of potential errors in semen aspiration, chamber quality, data acquisition, and analysis.
• Discussion of the impact of confounding factors and artefacts on results.

Main Results:

• Physical methods (turbidimetry, spectrophotometry, laser Doppler) are often too imprecise or complex for routine use.
• Computer-assisted semen analysis (CASA) systems can be tedious, time-consuming, and susceptible to artefacts and confounding factors.
• Single-step computer systems with manual tracking offer improved reliability but still depend on technician expertise.

Conclusions:

• Significant challenges persist in achieving objective and reliable sperm characteristic assessment.
• Multiple sources of error exist throughout the semen analysis workflow, from sample handling to data interpretation.
• Further development is needed to overcome the limitations of current technologies and ensure accurate male fertility diagnostics.