Effects of shortening the time of mifepristone on the ultrastructure and the expression of steroid receptors in human decidua tissue in early pregnancy

Objective To explore the feasibility of shortening the time of mifepristone in abortion. Mehtods Eighty women who desired to terminate the early pregnancy were divided into four groups: control group, 12 h group, 24 h group, 48 h group. The decidua tissues were collected after uterine aspiration. The morphological change of decidua tissue was observed by light microscope and transmission electron microscope. The expression of estrogen receptor (ER), progesterone receptor (PR) in decidua tissue were detected by immunohistochemistry technique and computer image analysis system. Results Three medication groups showed that the decidual cells degenerate, necrosis, interstitial edema and telangiectasis. In decidua tissue of control group, the expression of ER and PR was mainly in the decidual cell and a few in epithelial cells, which were significant lower in the three medication groups than in control group (P 0.05). Conclusion The decidua tissues have turned to dropsy, degenerate and necrosis by 12 h after oral mifepristone. And the expressions of ER and PR have already been inhibited. It is indicated that shortening the time of mifepristone in medical abortion provides a certain theoretical parameters. Key words: Mifepristone; Different time; Decidua; Steroid receptors; Ultrastructure