To investigate the impact of 2010 World Health Organization (WHO) reference values in patients who underwent microsurgical varicocelectomy.

This retrospective cohort study included 206 men who underwent microsurgical varicocelectomy for a clinical varicocele with at least 1 abnormal semen parameter according to the 1999 WHO criteria. The preoperative semen analysis findings were reclassified according to the 2010 WHO criteria, and an improved seminal result after varicocelectomy was defined as a ≥20% increase in sperm count or motility.

Semen results of 114 men (55.3%) were reclassified as being above the reference values according to the 2010 WHO criteria. Among those with below reference values, 79.3% and 34.8% showed improved sperm counts and motility, respectively. However, in patients whose semen results converted to normal, 47.4% and 20.2% showed improved sperm counts and motility, respectively. Among those whose semen results were normal on the 2010 criteria, 58.8% showed improved sperm count or motility after microsurgical varicocelectomy.

More than half of the patients whose semen results converted to normal on the 2010 WHO criteria showed improved seminal results after microsurgical varicocelectomy. It is necessary to reconsider the 2010 WHO criteria when determining the surgical indication for microsurgical varicocelectomy.