Associations among morphological parameters, clinical factors and euploid blastocyst formation

To evaluate the association among embryonic morphological parameters, clinical factors and euploid blastocyst formation.

This prospective cohort study included 422 blastocysts from 135 patients who had undergone preimplantation genetic analysis after intracytoplasmic sperm injection (ICSI).

Of 422 blastocysts, 200 (47.4%) were euploid and 222 (52.6%) aneuploid. Women aged older than 38 years were more likely to develop aneuploid embryos (OR: 3.4, CI: 2.2-5.4, p<0.001). Poor ovarian reserve (OR: 3.3, p<0.001), increased male age (39.0 versus 40.7, p=0.019), and decrease in sperm percentage with normal morphology (2.5% vs. 1.9%, p=0.047) were associated with aneuploidy. Type C trophectoderm (TE) and type C inner cell mass were associated with a high risk of embryo aneuploidy, with OR of 4.1 (CI: 2.2-7.7, p<0.001) and 1.7 (CI: 1.01-3.0, p=0.048), respectively. Logistic regression analysis revealed maternal age and type C TE as the main risk factors for aneuploidy. Among combinations of factors, the best marker for the risk of aneuploidy was maternal age older than 38 years, combined with a type-C embryo with trophectoderm, which showed a positive predictive value of 88.6% and a specificity of 97.5%.

Trophectoderm and type-C inner cell mass are the main embryo risk factors for aneuploidy, explaining approximately 71% and 60% of the risk, respectively. Among clinical factors, advanced maternal and paternal age (older than 38 and 36 years, respectively), antral follicles (<5), and a low percentage of sperm with normal morphology increased the risk of embryonic aneuploidy.