The Role of Low-Intensity Pulsed Ultrasound in Enhancing Endometrial Receptivity for Implantation in Infertile Women: A Randomized Controlled Trial

Background: Endometrial receptivity is a crucial factor for embryo implantation, and its deficiency is a major contributor to infertility and failure of in vitro fertilization (IVF). Low-Intensity Pulsed Ultrasound (LIPUS) has emerged as a promising non-invasive treatment for improving endometrial receptivity, with interest due to its affordability and minimal side effects. Objective: To assess the efficacy of LIPUS in enhancing endometrial receptivity for embryo implantation in infertile women with thin endometria. Methods: The study included sixty infertile women undergoing IVF treatment. The participants were randomly assigned to receive either LIPUS or traditional estrogen therapy (4 mg/day orally) for 14 days. The study assessed changes in endometrial thickness, blood flow, implantation, and pregnancy rates following treatment as indicators of endometrial receptivity. Results: LIPUS treatment significantly improved endometrial thickness (6.1-9.5mm), compared to a lesser increase in the estrogen group (6.2- 8.6mm, p=0.02). Doppler ultrasound parameters, including peak systolic velocity (PSV) and end-diastolic velocity (EDV), also displayed significant improvements in the LIPUS group (PSV: 36.4 vs. 31.3cm/s, p=0.01; EDV: 13.5 vs. 11.5cm/s). Although implantation and pregnancy rates were higher in the LIPUS group (60% vs. 40% and 53.3% vs. 33.3%, respectively), the differences were statistically insignificant. Conclusions: LIPUS may provide a feasible non-invasive alternative approach to traditional estrogen therapy for enhancing endometrial receptivity in IVF patients, potentially improving implantation and pregnancy outcomes, although further studies with larger sample sizes are required.