Association of paternal age with embryological outcomes and β-hCG positivity in women with polycystic ovary syndrome undergoing ICSI: a retrospective cohort study.

BACKGROUND: The independent effect of paternal age on assisted reproductive technology outcomes remains uncertain, particularly when maternal characteristics and conventional semen parameters are considered. This study investigated the association between paternal age and embryological outcomes and β-hCG positivity in women with polycystic ovary syndrome (PCOS) undergoing intracytoplasmic sperm injection (ICSI). METHODS: This single-center retrospective cohort study included 192 ICSI cycles in women with PCOS aged ≤35 years. Male partners were categorized as <35 years (n = 129), 35-39 years (n = 44), or ≥40 years (n = 19). Embryological outcomes included the numbers of retrieved oocytes, metaphase II (MII) oocytes, two-pronuclear (2PN) embryos, cleavage-stage embryos, and cryopreserved embryos, as well as fertilization, cleavage, and cryopreservation rates. β-hCG positivity was evaluated as the early pregnancy outcome. Multivariable logistic regression was used to assess the association between paternal age and β-hCG positivity after adjustment for female age, male and female body mass index, male smoking and alcohol use, baseline anti-Müllerian hormone, pre-OPU estradiol, sperm concentration, and sperm motility. RESULTS: Maternal age differed significantly among paternal age groups (p < 0.001), whereas sperm concentration and motility and other evaluated baseline characteristics were comparable. The numbers of retrieved oocytes, MII oocytes, 2PN embryos, cleavage-stage embryos, and cryopreserved embryos did not differ significantly among paternal age groups. Cleavage and cryopreservation rates were also comparable. Fertilization rate showed an overall between-group difference (p = 0.044); however, none of the pairwise comparisons remained significant after Bonferroni correction. β-hCG positivity was 63.6%, 45.5%, and 52.6% in the <35, 35-39, and ≥40-year groups, respectively (p = 0.095). In multivariable analysis, paternal age was not independently associated with β-hCG positivity (overall p = 0.358). CONCLUSION: Paternal age was not independently associated with β-hCG positivity or with a consistent deterioration in embryological outcomes among women with PCOS undergoing ICSI. Although an overall difference in fertilization rate was observed, this finding was not confirmed by corrected pairwise comparisons. These results should be interpreted cautiously because of the small ≥40-year subgroup and the absence of later pregnancy outcomes and molecular sperm-quality assessments.