Objective <p>The association between anti-Müllerian hormone (AMH) levels and embryonic aneuploidy rates was investigated by analyzing clinical and embryo laboratory data from patients with preimplantation genetic testing for aneuploidy (PGT-A). However, the nonlinear relationship and threshold effect of AMH on aneuploidy risk remain poorly understood.</p> Methods <p>This retrospective study analyzed the clinical data of 819 PGT-A cycles performed between January 2018 and August 2024 at the General Hospital of Northern Theater Command. We used restricted cubic spline (RCS) to investigate the dose–response relationship between the AMH levels and aneuploidy rate, adjusting for potential confounders.</p> Results <p>Significant differences were observed in normal fertilization rates, day 3 high-quality embryo rates, blastocyst formation rates, euploidy&#xa0;embryo rates, aneuploid&#xa0;embryo rates, and mosaic&#xa0;embryo rates among the three AMH groups (<i>P</i> &lt; 0.05). A statistically significant nonlinear relationship between AMH levels and aneuploidy rate was identified (<i>P</i> &lt; 0.05). RCS and threshold effect analyses revealed that the risk of a positive (≥ 50%) aneuploidy rate increased by 40% for each 1-unit decrease in AMH when AMH ≤ 2.54 ng/mL.</p> Conclusions <p>In the PGT-A population, advanced maternal age&#xa0;(AMA), recurrent spontaneous abortion (RSA), or recurrent implantation failure (RIF) have been identified as contributing factors. After adjusting for potential confounders such as female age, AMH remains a significant risk factor for embryonic aneuploidy rates. The findings suggested that lower AMH levels are associated with a higher risk of embryonic aneuploidy, indicating that ovarian reserve function may be correlated with oocyte quality. These results provide new insights for individualized decision-making in assisted reproduction.</p> <p><b>Trial registration</b> ChiCTR2500099710 (03/27/2025).</p>