Leukemia Inhibitory Factor Expression in Different Endometrial Locations Between Fertile and Infertile Women Throughout Different Menstrual Phases

Purpose: The purpose was to demonstrate the leukemiainhibitory factor (LIF) expression in different endometriallocations between fertile and infertile women throughoutdifferent menstrual phases. The relationship betweenprogesterone level and LIF expression were evaluated.Methods: Endometrial biopsies were performed onidiopathic infertile and normal fertile women accepted theinfollicular, periovulatory, and luteal phases. The lutealprogesterone level was measured. Endometrial LIFimmunostaining of luminal epithelium, glandular epithelium, andstroma were detected. The relationship between luteal LIFexpression and progesterone level was evaluated.Results: Significant LIF expression was noted in theendometrium of fertile women rather than that of infertile women.The LIF expression was highest in the luminal epithelium,moderate in the glandular epithelium, and lowest in thestroma. The luminal and glandular epithelial staining werelowest in follicular phase, moderate in periovulatory phase,and strongest in luteal phase. The stromal LIF presentedwith a noncyclical manner. The LIF expression is not relatedwith the progesterone level.Conclusions: Endometrial LIF expression is related tohuman fertility. Endometrial LIF expression is dependenton cellular localizations and menstrual stages. Stronger LIFexpression presents in the endometrial epithelium duringluteal phase.