OC15.03: Application of multimodal ultrasound to evaluate endometrial receptivity in patients with unexplained infertility

To investigate the value of multimodal ultrasound (transvaginal 2D, 3D, 4D, and SE ultrasound) in the evaluation of endometrial receptivity (ER) in patients with unexplained infertility. 78 patients with unexplained infertility (infertility group) and 78 healthy postpartum women (normal group) each were recruited at our hospital. Multimodal ultrasonography was performed in both groups of volunteers during the implantation window to obtain 2D ultrasound indices (endometrial thickness, echo type, blood flow grading, uterine artery PI, RI, S/D values), 3D ultrasound indices (endometrial volume and endometrial VI, FI, VFI, maximum thickness of the endometrium-myometrium binding zone JZ tJZmax, minimum thickness tJZmin, difference between maximum and minimum thickness tdJZ, mean thickness tmJZ), 4D ultrasound indices (direction and frequency of endometrial peristalsis in each wall in the sagittal and coronal planes of the uterus) and SE indices (endometrial stress values, myometrial stress values, endometrial stress ratio). The univariate analysis showed statistically significant differences (P<0.05) in endometrial thickness, uterine artery flow spectrum (PI, RI, S/D values), tdJZ, and mean frequency of uterine wall peristalsis between the two groups. Binary logistic regression analysis showed that endometrial thickness, uterine artery PI and coronal fundal mean frequency were influential factors for ER in infertile patients (regression coefficients of 2.559, 2.127, -0.375, ORs of 12.927, 8.393, 0.687, respectively, all P<0.05). The ROC curve analysis showed that the AUCs for the composite index, uterine artery PI, coronal fundal mean frequency, and endometrial thickness for diagnosing ER in infertile patients were 0.817, 0.719, 0.689, and 0.665, respectively. Endometrial thickness, uterine artery PI and coronal fundal mean peristaltic frequency are the influencing factors of ER in patients with unexplained infertility, and it is valuable to evaluate ER in infertility patients by combining these factors.