Leukemia Inhibitory Factor a Marker of Implantation Success in Unexplained Infertility: a Randomized Controlled Trial

Uterine receptivity and implantation are complex processes requiring coordinated expression of molecules by zygote and uterus. Leukemia inhibitory factor (LIF) is one of the most important cytokines in the reproductive tract. Without expression of LIF in the uterus, implantation of a blastocyst cannot begin. Our objectives were to measure the leukemia inhibitory factor (LIF) concentration in serum with or without endometrial scratch-ing in women with unexplained infertility.

This study is a randomized control trial, carried out at the infertility clinic of Qena University hospital, South Valley University, Egypt. The study included 200 women with unexplained infertility divided into two groups: Group 1 included 100 patients undergoing endometrial scratching at mid luteal phase. Group 2 included 100 patients undergoing expectant management. Serum leukemia inhibitory factor (LIF) concentration was measured at mid-luteal phase of cycle and follow up of pregnancy occurrence in both groups.

LIF was significantly higher in the group of endometrial scratching compared to group 2. LIF was significantly higher in pregnant women compared to non-pregnant ones in both the endometrial scratching group and group 2. For the endometrial scratching group, LIF was a significant marker for successful implantation at cutoff point of 97.2 with sensitivity of 97.3% and specificity of 77.8% while PPV was 72% and NPV was 98.

Endometrial scratching was associated with higher level of LIF and pregnancy rate. LIF was significantly higher in pregnant women with or without endometrial scratching.