Impact Of Maternal Age on Embryo Chromosomal Competence: A Retrospective Analysis of 4,204 Consecutive PGT-A Blastocysts from a High-Volume IVF Center

Abstract

Background: Maternal age is the most important determinant of embryo chromosomal competence and remains the strongest predictor of IVF success. Although preimplantation genetic testing for aneuploidy (PGT-A) has become an integral component of modern assisted reproductive technology (ART), large single-center studies evaluating comprehensive chromosomal outcomes across different maternal age groups remain relatively limited. Therefore, this study aimed to evaluate the association between maternal age and embryo chromosomal status in a large cohort of consecutive blastocysts analyzed by PGT-A.

Methods: This retrospective cohort study included 495 women undergoing IVF/ICSI with PGT-A between January 2025 and January 2026 at a high-volume IVF center. Patients were stratified into three maternal age groups: Group I, aged 20-29 years (n = 90); Group II, aged 30-39 years (n = 226); and Group III, aged 40-43 years (n = 179). Only patients with at least six biopsied blastocysts were included. A total of 4,204 blastocysts underwent trophectoderm biopsy followed by comprehensive chromosome screening using next-generation sequencing (NGS). The primary outcome was the proportion of euploid embryos. Secondary outcomes included the proportions of aneuploid, mosaic, and segmental-abnormality embryos, as well as samples yielding no result.

Results: Among the 4,204 blastocysts analyzed, 2,826 (67.2%) were euploid, 731 (17.4%) were aneuploid, 240 (5.7%) were mosaic, and 322 (7.7%) demonstrated segmental abnormalities; 85 (2.0%) yielded no result. Age-stratified analysis demonstrated a progressive decline in embryo euploidy with advancing maternal age, accompanied by increasing rates of chromosomal abnormalities.

Conclusions: Maternal age remains the strongest determinant of embryo chromosomal competence. Although high laboratory performance resulted in a very low technical failure rate, advancing maternal age was associated with reduced euploid embryo yield and increasing chromosomal abnormalities. These findings support individualized reproductive counseling and emphasize the clinical value of PGT-A in women of advanced reproductive age.