Abstract: Objective To explore the expression of Leukemia inhibitory factor(LIF )and Leukemia inhibitory factor receptor (LIFR) signal in the primary infertile women endometrium with different causes during the implantation window and the relationship between LIF、LIFR and unexplained infertility. Method sIn the prospective clinical controlled study,200 patients with infertile from Jan.2015 to Jan.2017 in our hospital were divided randomly into tubal factor(group A),poor ovarian reserve(group B),endometriosis (group C) and unexplained infertility (group D) according to different pathogenesis.Then,normal women were selected during the same period as the control group,the endometrial expression of LIF and LIFR were detected by fluorescence quantitative PCR,while the differences were compared between groups. Results The expression level of LIF in the control group was (1.12±0.46),while in A,B,C and D group were (1.03±0.33),(0.90±0.30),(0.99±0.38) and (0.50±0.31),respectively.There was no significant difference in the expression of LIF between the three groups of A,B,C and the control group,but the expression level of LIF in D group was significantly lower than that of the control group(P<0.01). The endometrial expression of LIF was significantly decreased in D groups than that of the other infertile groups.The endometrial LIFR in four infertile groups were all significantly decreased (P<0.01),while there was no statistical difference between the subgroups (P>0.05). Conclusion The endometrial LIFR expression in general infertile women might be impaired,which deduced that LIFR might be one of the key factors for the pregnant regulation in female endometrial planting window. Deletion of LIF may be associated with unexplained infertility.

Key words: Leukemia inhibitory factor, Leukemia inhibitory factor receptor, Infertility, Endometrium