The features of endometrial receptivity in women underwent in vitro fertilization procedure.

The objective: to determine the endometrial receptivity markers in women who underwent the procedure of in vitro fertilization (IVF). Materials and methods. The study included 191 patients who applied to the reproductive department of Caspian International Hospital from 2020 to 2022 for an examination for infertility. The main group included 50 patients with infertility who underwent endometrial biopsy during the implantation window (7th–9th days after ovulation in the cycle preceding the IVF stage); the control group – 20 women who underwent treatment for male infertility with a positive program result. The patients underwent IVF according to the standard method. The following expression levels were determined: leukemia inhibiting factor (LIF); vascular endothelial growth factor (VEGF); transforming growth factor-β1 (TGF-β1). The percentage expression of area indices was estimated. Results. In the women of the main group absence of embryo transfer was in 5 (10%) cases, no pregnancy – 27 (54%) cases, presence of pregnancy – 23 (46%) cases, cycle disruption – 3 (6%) cases. According to the results of a histological examination in women of the control group, complete secretory transformation of the endometrium was determined in 85% of cases. In the main group complete secretory transformation of the endometrium was detected in 48%, defective secretory transformation – in 42%, morphological signs of endometrial changes corresponding to the average secretory phase of the cycle – in 10% of women. A significant decrease (p<0.001) in the expression of LIF in the histological structures (stroma) of the endometrium was revealed in the main study group compared to the control one. The most pronounced differences were observed in the expression level of TGF-β1 in the stroma (approximately 10-fold; p<0.001). Conclusions. Thus, infertile women who underwent IVF have multidirectional changes in endometrial receptivity markers: decrease in LIF expression in the stroma and epithelium, increase in VEGF expression in the stroma, and a significant increase in TGF-β1 expression in the stroma and epithelium. These changes indicate an abnormal functional state of the endometrium and affect the results of IVF in patients (absence of oocyte transfer and failure to conceive). [ABSTRACT FROM AUTHOR]