Objective
To investigate the effect of levonorgestrel and mifepristone on the expression of endometrial receptivity markers in a three-dimensional endometrial construct. Design: In vitro study. Setting: University hospital and research laboratory. Patient(s): Twelve fertile donors. Intervention(s): Timed endometrial biopsy. Main outcome measure(s): Examine the effect of levonorgestrel along with another well-studied fertility-regulating drug, mifepristone, on the expression of endometrial receptivity factors in a three-dimensional stromal and epithelial cell coculture model by immunohistochemistry. Result(s): Both epithelial and stromal cells of in vitro endometrial construct showed the presence of estrogen receptor-alpha, estrogen receptor-beta, progesterone receptors-(A+B), vascular endothelial growth factor, leukemia inhibitory factor, interleukin-1 beta, and cyclooxygenase-2, whereas the expression of progesterone receptor-B (AR), integrin alpha(V)beta(3,) and MUC1 were confined to epithelial cells. Mifepristone up-regulated expression of epithelial estrogen receptor-beta and progesterone receptor-B and down-regulated stromal vascular endothelial growth factor and surface molecules MUC1 and integrin alpha(V)beta(3) as observed in vivo. Levonorgestrel had no effect on the expression of endometrial receptivity markers studied.