Expressions of Leukemia Inhibitory Factor (LIF): Comparison of Normal Pregnancy and Recurrent Abortion

Objective : Successful implantation depends on a complex interaction between the developing blastocyst and the endometrium. Among the steroid hormones, growth factors, and cytokines which participate in preparing the uterus for implantation, leukemia inhibitory factor (LIF) plays an essential role in implantation. We compared the expression of LIF in normal pregnancies to that of recurrent abortions in placenta to elucidate whether spontaneous abortion and expression of LIF has correlation. Methods : Placental tissues from normal pregnancies and recurrent abortions were fixed and embedded in paraffin. Standard immunohistochemical staining was used to identify LIF. Results : LIF expressions on cytotrophoblast of recurrent abortion were lower than those of normal pregnancy. There were no expressions on syncytiotrophoblast and stroma in the both groups. In the decidua and gland, LIF was expressed in mild degree and there were no differences in LIF expression between normal pregnancy and recurrent abortion. Conclusion : LIF expression on cytotrophoblast of recurrent abortion was lower than that of normal pregnancy. LIF may provide paracrine and autocrine signals to both embryonic tissues and uterine epithelium during implantation. The dysfunction of LIF production may be a cause of the unexplained recurrent abortions.