During the analysis of the expression of the major genetic markers of decidualization, the hormone prolactin (PRL), the progesterone receptor gene (PCR), the estrogen receptor (ESR), insulin-like growth factor binding protein 1 (IGFBP) and forkhead box protein O1 (FOXO1), we revealed changes in PRL, PCR, ESR, IGFBP, FOXO1 expression in time manner and difference in the groups (healthy vs. infertile). Here, ESR1 is linked to Infertility.