Endometrial elasticity in infertile women assessed by transvaginal shear wave elastography

Endometrial receptivity (ER) is critical for embryo implantation, and its impairment is a major contributor to infertility. Current ER evaluation methods are invasive and poorly standardized. Shear wave elastography (SWE) offers a noninvasive means of quantifying tissue stiffness, but its utility in ER assessment is underexplored. This study aimed to investigate the differences in endometrial elasticity between infertile patients and healthy controls across the menstrual cycle using transvaginal SWE.

This prospective study was conducted at The Third Affiliated Hospital of Guangzhou Medical University between March and September 2023. Infertile patients and healthy women of reproductive age were enrolled. Transvaginal ultrasound SWE was used to assess endometrial thickness and stiffness parameters, including mean (Emean), maximum (Emax), and minimum (Emin) elastic modulus values during the proliferative and secretory phases of the menstrual cycle.

A total of 169 participants were included, comprising 114 infertile patients and 55 healthy controls aged 28-35 years. No significant differences were observed between the groups in endometrial thickness or pattern distribution during either the proliferative or secretory phase (all P>0.05). During the proliferative phase, infertile patients showed significantly higher Emean and Emax values than healthy controls in both the anterior and posterior walls (anterior Emean: 32.26 vs. 23.06 kPa, P<0.001; anterior Emax: 63.47 vs. 41.47 kPa, P<0.001; posterior Emean: 34.91 vs. 26.77 kPa, P = 0.002; posterior Emax: 62.01 vs. 46.65 kPa, P=0.021). During the secretory phase, infertile patients exhibited significantly higher Emean values in both walls (anterior: 20.18 vs. 16.10 kPa, P=0.019; posterior: 21.23 vs. 16.00 kPa, P=0.006). Receiver operating characteristic (ROC) analysis indicated good discriminative performance for anterior wall Emean [area under the curve (AUC) =0.775] and Emax (AUC =0.784).

Infertile patients exhibit increased endometrial stiffness, particularly during the proliferative phase, and transvaginal SWE-especially anterior wall Emean and Emax-may serve as a noninvasive tool to assess ER.