Developmental arrest rate of an embryo cohort correlates with advancing reproductive age, but not with the aneuploidy rate of the resulting blastocysts in good prognosis patients: a study of 25,974 embryos

This study aimed to investigate the extent to which developmental arrest rate in embryos generated using assisted reproduction correlate with female age and the rate of aneuploidy in the cohort. A total of 25,974 embryos from 1,928 cohorts were included in the study, with an overall embryo developmental arrest (EDA) rate of 40.3% (95% CI: 39.8-40.9%). The median EDA rate increased with age: 33.0% (IQR: 22.0-50-0%) in <35 years old, 38.0% (25.0-50.0%) in 35-37 years old, 40.0% (29.0-54.0%) in 38-40 years old, 44.0% (38.8-56.5%) in 41-42 years old, and 44.0% (40.0-58.0%) in >42 years old; p < 0.0001. A very weak positive correlation was identified between EDA rate and the rate of aneuploidy (r: 0.07, 95% CI 0.03-0.11; R²: 0.00, p < 0.01) when evaluating all cohorts. However, when adjusting for age, no statistically significant relationship between aneuploidy and EDA was observed. Our findings suggest that the rate of EDA and the rate of whole chromosome aneuploidy in the resulting blastocyst cohort are both associated with female age, but not with each other. Therefore, EDA and aneuploidy rates represent two independent factors in determining the number of euploid embryos available for transfer and the overall likelihood of ART success.