Endometrial tolerance is one of the key factors for pregnancy success, yet traditional assessment methods such as endometrial thickness often do not fully reflect the true state of the endometrium. With the continuous advancement of imaging technology, ultrasound imaging, especially the combination of three-dimensional ultrasound and multimodal ultrasound, provides a new technological tool for assessing endometrial tolerance. In this study, endometrial tolerance was quantified using color Doppler three-dimensional ultrasound, which was aimed at assessing its predictive value for IVF-ET pregnancy outcome. One hundred and thirteen female patients proposed for assisted reproduction were selected for the study and divided into case and control groups and endometrial morphology, thickness, volume and hemodynamic parameters were collected. The results showed that the difference in endometrial thickness between the PCOS group and the control group was not statistically significant (P>0.05), but the endometrial elastic modulus values were significantly higher (P<0.05). In multimodal ultrasonography scores, endometrial thickness score, VFI index score and total multimodal ultrasonography score were significantly lower in the case group than in the control group (P<0.05). In addition, there was a significant positive correlation between endometrial blood flow VI, FI and VFI and VEGF mRNA expression level (r 0.744, 0.522, 0.435, respectively, P<0.01). These results suggest that 3D ultrasound combined with hemodynamic parameters can effectively reflect endometrial tolerance and provide a new assessment method for pregnancy prediction in IVF-ET.
