Objective: To discuss the role, reliability and limitations of the semen analysis in the evaluation of fertility with reference to the World Health Organization (WHO) fifth edition guidelines, with semen analysis reference values published in 2010. We also discuss the limitations of using a single threshold value to distinguish 'abnormal' and 'normal' parameters.
Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used to search the MEDLINE, EMBASE, and the Cochrane electronic database for articles discussing the effectiveness of semen analysis.
Results: Limitations affecting the reliability of semen analysis as a predictor of fertility were found. These include: the lack of consideration of the female factor, the vaguely defined threshold values, and the intra-individual variation in semen parameters.
Conclusions: Impaired semen parameters alone cannot be used to predict fertility as these men still have a chance of being fertile, except when a man has azoospermia, necrospermia or globozoospermia.
Keywords: ASA, anti-sperm antibodies; Fifth edition guidelines; Laboratory manual; Male infertility; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyse; Prediction; Semen analysis; WHO.