Objective: The microenvironment of the oocyte is composed of granulosa cells (GC), which play a vital role in the process of oogenesis.During Assisted Reproductive Technology (ART) treatment, the morphological characteristics of GC are evaluated. However, thisevaluation does not provide definitive clarity.

There is a limited amount of research on the underlying mechanisms of abnormal GCmorphology, and it remains incompletely understood. Therefore, the aim of our study was to investigate apoptosis in GCs with variedmorphologies in patients with different infertility etiologies undergoing intracytoplasmic sperm injection (ICSI).

We performed animmunohistochemical analysis of caspase-3, cytochrome c, and heat shock protein-70 (HSP-70) expression levels, and evaluated theirimpact on assisted reproduction.Patients and Methods: The study comprised 142 patients, including 65 with polycystic ovary syndrome (PCOS) and 77 with malefactor (MF) infertility.

The granulosa-oocyte complex was analyzed under a stereomicroscope and classified into dark granulosa cells(DGC) and light granulosa cells (LGC). Fertilization rates, embryonic development, and pregnancy outcomes following ICSI wereevaluated. DGC exhibited reduced fertilization and pregnancy rates.Results: Caspase-3 and cytochrome c expression levels were significantly elevated in the PCOS DGC (26, 86.6%; 25, 83.3%) and MFDGC (34, 77.2%; 32, 72.7%) groups compared to the PCOS LGC (8, 22.8%; 5, 14.2%) and MF LGC (4, 12.1%; 7, 21.2%) groups (p =0.001; p = 0.001), respectively.

In contrast, expression levels of HSP-70 were significantly lower in the PCOS DGC (6, 20%) and MFDGC (7, 15.9%) groups compared to the PCOS LGC (31, 88.5%) and MF LGC (32, 96.9%) groups (p = 0.001).Conclusion: In the PCOS group, the number of good quality embryos on day 3 exhibited a positive correlation with HSP-70 expressionlevels and a negative correlation with cytochrome c expression levels.

Our findings suggest that DGC morphology is a reflection ofapoptosis, which impacts oocyte quality and, consequently, embryonic development, with PCOS contributing to the worsening of thiscondition.