Sperm retrieval, fertilization rates, and clinical outcomes of infertile men with Y chromosome microdeletion: A retrospective cohort study.

Abstract

Introduction: In this study, we aimed to explore whether a Y chromosome microdeletion (YCM) confers adverse effects on surgical sperm retrieval potential and intracytoplasmic sperm injection (ICSI) outcomes in men with azoospermia and severe oligospermia.

Methods: This was a retrospective cohort study, which included infertile men with azoospermia or severe oligospermia who were evaluated for karyotype analysis and YCM testing at a university-affiliated hospital between 2010 and 2022. Outcomes of microdissection testicular sperm extraction (mTESE) for surgical sperm retrieval were compared between men diagnosed with YCM and the control group in which no YCM were found. Additionally, patients from each group who underwent in-vitro fertilization (IVF) - ICSI cycle using ejaculated sperm or surgically retrieved mature spermatozoa were compared regarding their IVF-ICSI cycle outcomes - fertilization rates, cleavage, and blastocyst formation and clinical pregnancy rates.

Results: A total of 116 azoospermic and oligospermic men who underwent Y chromosome microdeletion testing were included in the study: 19 men with YCM and 97 controls without YCM. Overall, nine mTESE procedures were performed for patients with YCM and 38 mTESE procedures were done on men from the control group. There were no significant differences between the YCM and control groups in mature sperm retrieval rates (11.1% vs. 26.3% p=0.663), though a trend towards higher rates of findings of elongated and round spermatids as the most mature germ cell was noted in the YCM group (66.7% vs. 28.9%, p=0.054). Out of the 13 men with mature sperm - either ejaculated or surgically retrieved (mTESE) - that had known ICSI cycle outcomes, three men had proven YCMs and 10 controls had no identified YCMs. Basic characteristics were similar between the groups, except for testosterone levels, which were higher in the YCM group (23.0±13.1 vs. 9.4±6.4 nmol/L, p=0.027). Fertilization rates and cleavage rates were similar between the YCM and control groups (42.3% vs. 49.7% and 42.3% vs. 39.3%, p=0.491 and 0.774, respectively). Blastocyst formation rates, and pregnancy rates, while not statistically significant, showed a trend for favorable outcomes in the control group compared to the YCM group (24.1% vs. 7.7%, 72.7% vs. 20.0%, p=0.078 and 0.106, respectively).

Conclusions: Y chromosome microdeletion does not affect sperm retrieval rates. Fertilization and cleavage rates are not impaired by microdeletions, while blastocyst formation rates and clinical pregnancy rates per embryo transfer follow a non-significant trend for unfavorable outcomes in the YCM group. Clinical and embryonic development results should be interpreted with caution, as these groups are relatively small.