Low-Level Laser Therapy for Improvement of In Vitro Fertilization Outcomes in Patients with Recurrent Implantation Failure: A Randomized Clinical Trial.

Introduction: Numerous strategies have been investigated for addressing recurrent implantation failure (RIF) and enhancing endometrial receptivity, yet agreement on the optimal intervention remains elusive. Our investigation endeavors to assess the effect of low-level laser therapy (LLLT) on pregnancy outcomes in individuals who have undergone a minimum of three unsuccessful embryo transfer cycles (ET). Methods: In our randomized single-blinded clinical trial, we enrolled thirty females with a medical history of RIF who were eligible for frozen-thawed embryo transfer (FET). Through a random allocation sequence, the participants were divided into two groups. The LLLT was performed one cycle before blastocyst transfer in 15 cases using a New Age BIOLASER device (New Age Co., Italy) with a 900-milliwatt power output and an 850-nm wavelength. The irradiation sessions were conducted transabdominal on the hypogastric area. The considered outcomes were biochemical pregnancy, identified by a positive blood pregnancy test, and clinical pregnancy, confirmed through visualization of the gestational sac using ultrasonography. Results: The mean age of the subjects was 34.17 years, and they had undergone three to seven previous embryo transfers. There was no significant difference in basic characteristics between the group undergoing laser treatment and the control group. However, the laser-treated group exhibited elevated rates of both biochemical and clinical pregnancies compared to the control group (46.7% vs. 33.3%; P ==0.710 and 33.3% vs. 20.0%; P =0.682 respectively). Conclusion: To our knowledge, this study represents the first single-blinded randomized clinical trial to assess the effectiveness of LLLT pretreatment in individuals with RIF. The findings propose that LLLT may potentially enhance biochemical and clinical pregnancy rates among RIF patients.