Developmental Versus Chromosomal Competence in Endometriosis: A Stepwise IVF Outcome Analysis

Background and Objectives: Endometriosis is a multifactorial gynecological condition associated with impaired fertility; however, its impact on embryo competence remains incompletely understood. This study aimed to evaluate embryo competence through a stepwise analysis of IVF outcomes across the developmental continuum, while also comparing patients with endometriosis and controls. Materials and Methods: A retrospective observational study was conducted, including 160 patients undergoing IVF, comprising 55 patients with endometriosis and 105 controls. Clinical and embryological data were analyzed sequentially across key developmental stages, including oocyte retrieval, metaphase II (MII) oocyte formation, fertilization (2PN), embryo development, and euploidy in a subgroup undergoing preimplantation genetic testing for aneuploidy (PGT-A). Stage-specific efficiency rates were calculated, and correlations between early- and late-developmental parameters were assessed. In addition, comparative analysis between groups was performed. Results: A progressive decline in developmental efficiency was observed across the IVF continuum, with approximately one-quarter of retrieved oocytes reaching the embryo stage and only a small proportion ultimately resulting in euploid Blastocysts. Strong positive correlations were identified among early-stage parameters, particularly retrieved oocytes, MII oocytes, and embryo yield (r = 0.77-0.96, p < 0.001), indicating that ovarian response and oocyte maturity significantly influence downstream outcomes. However, efficiency-based parameters showed limited predictive value for chromosomal competence. A moderate association was observed between MII oocytes and euploid Blastocysts (r = 0.58), whereas the relationship between embryo number and euploidy remained weak. Comparative analysis revealed no statistically significant differences between the endometriosis and control groups across the evaluated embryological parameters (p > 0.05 for all comparisons), suggesting that sequential analyses may provide complementary insight beyond direct comparisons. Conclusions: IVF outcomes follow a sequential developmental trajectory with a progressive decline in efficiency across stages. In endometriosis, early developmental competence appears to be affected, while chromosomal competence remains relatively preserved.