Y-Chromosome Structural Abnormalities and Male Fertility: Semen Analysis and Assisted Reproduction Outcomes in a Retrospective Cohort

Objective: To describe the spectrum of Y-chromosome structural abnormalities, examine their relationship with semen parameters, and evaluate the outcomes of assisted reproductive procedures (e.g., intracytoplasmic sperm injection [ICSI] and microdissection testicular sperm extraction [mTESE]) associated with affected men. Methods: From January 2020 to December 2023, 21,638 male patients underwent karyotyping at the Andrology and Fertility Hospital of Hanoi, Vietnam. Among them, 21 cases of Y-chromosome structural rearrangements were identified, including 11 Y–autosome translocations, 9 Y-chromosome inversions, and 1 isodicentric Y chromosome. Clinical data, semen parameters, azoospermia factor (AZF) microdeletion testing, and surgical sperm retrieval outcomes were retrospectively analyzed. Results: The incidence of Y-chromosome structural rearrangements was 0.09% (21/21,638). Azoospermia was observed in 6 of 21 patients (28.6%). Nine patients (42.8%) had abnormal semen parameters, including teratozoospermia and various forms of oligoasthenoteratozoospermia. Only 6 patients (28.6%) had normal semen parameters. No microdeletions were detected in the AZF regions in all patients with azoospermia. Among them, four underwent mTESE, but no sperm was retrieved. Among 12 patients with embryo transfer cycles, 5 (41.7%) achieved live births, including some cases involving lower-grade, day-6 blastocysts. Conclusion: Y-chromosome structural rearrangements, especially Y–autosome translocations, appear to be linked to higher rates of azoospermia and impaired spermatogenesis. Further studies with larger sample sizes are needed to clarify these associations.