Indication for Y chromosome microdeletion analysis in infertile men: Is a new sperm concentration threshold needed?

OBJECTIVE To describe the prevalence of Y-chromosome deletions in patients with a sperm concentration of less than 5 million/mL. To also determine a new sperm threshold for Y-chromosome analysis in men with infertility. METHODS A total of 3023 patients who had a semen concentration of less than 5 million/mL included in this retrospective study. All of these patients had a genetic evaluation, hormonal evaluation, and 2 abnormal semen analyses. RESULTS Y-chromosome deletions were present in 116 (3.8 %) patients with sperm concentration <5 million/mL. The frequency of a Y-chromosome deletions was 6.8%, 1.0%, 0.15% in azoospermic men, in men with sperm concentrations of 0-1 million /mL, in men with sperm concentrations of 1-5 million/mL. Patients were divided into 2 groups regarding the determined new sperm threshold. The sensitivity and specificity of the Y-chromosome deletions test were 92.2.7% and 49.3 %, 99.1%, and 22.1% in patients with azoospermia and sperm concentrations <1 million/mL, respectively. If the sperm concentration thresholds of azoospermia or <1 million/mL, are applied, the number of tests decreased to 50.5% (1442 tests) and 23.1% (643 tests), respectively. Approximately $108,150 and $48,225 would be saved if the sperm thresholds were azoospermia and <1 million/mL, respectively CONCLUSION: The current threshold of sperm concentration for Y-chromosome deletions is controversial. The new proposed sperm threshold for genetic testing of 1 million/mL would increase sensitivity and more cost-effective compared to the current threshold.