Supplementary file 1_Pretreatment AMH–AFC stratification of poor-ovarian-response risk in young women with diminished ovarian reserve: a multicentre retrospective cohort study.docx

Total AFC (adjusted OR 0.843) and ln (AMH) (OR 0.310) carried the main pretreatment signal; age and basal FSH added little. The two single-marker cells had similar observed POR rates (46.4% vs 49.6%; P = 0.56), but equivalence was not established. The AFC ≤5 boundary was reproduced in the seed-2024 70:30 split and was re-selected in 92.0% of 1,000 bootstrap samples when the cut-off was chosen in-bag and evaluated out-of-bag.

The descriptive three-tier rates were 23.9%, 47.1%, and 78.8%; when all 1,754 eligible cycles were retained, the middle-tier rate fell to 39.5%. For the fixed two-marker specification, bootstrap optimism correction gave an AUC of 0.768; centre-held-out AUCs using verified record-level centre labels ranged from 0.725 to 0.800. AMH and AFC therefore provide moderate pretreatment risk stratification within this young DOR cohort, but the absolute tier risks remain sensitive to cohort definition and cut-off choice.

External validation and recalibration are required before clinical use.</p>