Can blastocyst formation rate play a role as a predictor of PGT-A cycle outcomes?

OBJECTIVE To investigate clinical and embryological parameters that may serve as predictors of pregnancy outcomes in preimplantation genetic testing for aneuploidy (PGT-A) cycles. MATERIALS AND METHODS A total of 98 PGT-A cycles at a private in-vitro fertilization (IVF) center between April 2022 and July 2025 were enrolled. Trophectoderm biopsy cases without any known uterine anomalies and endometrial factor are included. Ovulation induction with letrozole (n=29) or hormone replacement therapy (HRT) (n=69) were used for endometrium preparation. Clinical and embryological cycle characteristics are analysed. Blastocyst formation rate (BFR) was calculated as the number of blastocysts per MII, and the euploidy rate refers to euploid embryos per biopsied embryos. Statistical analysis included t-tests or Mann-Whitney U for continuous variables, and Chi-square test for categorical variables. To identify potential confounding factors subgroup analyses and multivariate logistic regression were performed. RESULTS Among the 98 patients, 62 (63.3%) achieved pregnancy and 36 (36.7%) did not. There were no significant differences between the groups regarding age, BMI, total gonadotropin dose, or stimulation duration. Recombinant FSH agents were the most frequently administered (n=38), followed by hMG (n=23), combination of both (n=15) and recombinant FSH+recombinant LH (n=22). Analyzing the pregnancy results, no statistically significance was observed regarding the agents used, (p>0,05). The BFR was significantly higher in the pregnant group (0.36 ± 0.28) compared to the non-pregnant group (0.27 ± 0.24, p = 0.045). The estradiol/oocyte ratio was slightly higher in the pregnant group (319 ± 180 pg/mL) than in the non-pregnant group (287 ± 148 pg/mL), although not statistically significant (p = 0.48). The euploidy rate per was 59.3% (89/150) in the pregnant group and 68.8% (66/96) in the non-pregnant group, being not statistically significant (p = 0.13). Regarding confounding factors (female or male aneuploidy, the type of gonadotropin, the type of endometrial preparation protocol), none of these demonstrated a statistically significant association with pregnancy outcome in either univariate or multivariate models. CONCLUSIONS Given our results, BFRs may predict pregnancy outcomes whereas euploidy rates do not, despite being higher in non-pregnant cases contrary to expectations. IMPACT STATEMENT BFR in PGT-A cycles may help clinicians both to counsel current patients and to shape more individualized management strategies for future cases.