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

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?

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.

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).

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.