Prognostic role of endometrial pattern compared with thickness and estradiol in euploid HRT-FET cycles.

BACKGROUND: Do endometrial pattern types show an association with clinical outcomes in an IVF-ET cohort with pattern diversity, and do endometrial thickness and serum E2 and P4 levels measured on the day of endometrial assessment provide additional predictive value regarding reproductive outcomes? METHODS: This retrospective HRT-FET study included 237 euploid blastocyst transfer cycles. The effects of endometrial pattern types (Type A-B-C) on pregnancy, miscarriage, and live birth were evaluated; the relationship between endometrial thickness and hormonal parameters and reproductive outcomes was analyzed; and predictive performance was assessed. RESULTS: Significant differences were observed between endometrial pattern types for total pregnancy, biochemical pregnancy, miscarriage, and live birth rates (p = 0.004), with Type A showing the highest live birth rate. Endometrial thickness did not differ across pattern groups (p = 0.3819) or pregnancy outcome (p = 0.5676). Thickness categories showed significant distribution difference (p = 0.014), with higher live birth rates in >10.1 mm. ROC analyses indicated no predictive value for endometrial thickness in pregnancy (AUC = 0.505; cut-off 8.75 mm) or live birth (AUC = 0.5103; cut-off 11.85mm). E2 and P4 levels did not differ between pattern types (E2 p = 0.3819 and p = 0.2646; P4 p = 0.0799 and p = 0.2928), and ROC analyses for E2 showed limited predictive power in Type A (AUC = 0.5505; cut-off 279.5pg/ml) and Type B (AUC = 0.5382; cut-off 369.5pg/ml). CONCLUSIONS: Endometrial pattern may be associated with clinical outcomes, whereas endometrial thickness and serum E2 levels demonstrated limited discriminatory power. These findings highlight the heterogeneity in the existing literature and indicate that their role in decision-making during HRT-FET cycles should be reconsidered.