A pilot study of the intrauterine non-ablative erbium laser effectiveness in the endometrium preparation for cryopreserved embryo transfer in women with a history of implantation failures

Background. Embryo implantation failure remains an urgent issue of assisted reproductive technologies (ART). Aim. To determine the effect of intrauterine irradiation with a non-ablative erbium laser on the endometrium state using the histological and immunohistochemical examination and to evaluate its effectiveness in ART cryo-protocols. Materials and methods. The study enrolled 25 women aged 2645 with 1 to 5 failed implantations who were planning a pregnancy in a cryopreserved embryo transfer protocol. On days 610 of the menstrual cycle, all patients underwent a single procedure of intrauterine irradiation of the endometrium and cervical canal mucosa with an erbium laser in a non-ablative mode using Fotona SP Dynamis laser system (Slovenia). The histological and immunohistochemical data of the endometrium before and 12 months after the procedure and the pregnancy rate with subsequent transfer of the cryopreserved embryo were assessed. Results. Intrauterine irradiation with a non-ablative erbium laser increased the proliferative activity of the endometrium (p=0.029), the expression of vascular endothelial growth factor (p=0.029), reduced the sclerosis lesions in the spiral arteries and endometrial stroma, increased the expression of progesterone and estrogen receptors, thus significantly increasing the effectiveness of the ART cryo-protocols (p=0.013).