Apoptosis and proliferation in human chorionic villi and deciduae during spontaneous abortion

Objective To investigate the mechanism of spontaneous abortion in early pregnancy from apoptosis and proliferation.Methods Apoptosis and proliferation in early pregnant chorionic villi and deciduae from surgical aspiration and spontaneous abortion were studied. Histological changes were observed with light microscopy. Proliferating cell nuclear antigen (PCNA) was assayed by immunohistochemical staining; apoptosis cell death was detected by using DNA in situ terminal deoxynucleotidyl transferas mediated dUTP biotin nick ending labeling(TUNEL); both bcl 2 and bax gene protein were detected by using immunohistochemistyry. Results In chorionic villi after spontaneous abortion, there were extensive pathological changes in cell morphology. In spontaneous abortion, proliferating indexes of cytotrophoblasts and deciduas decreased in comparison with their counterparts in surgical aspiration ( P 0.01), and proliferating indexes of syncytiotrophoblasts were 0. While apoptosis indexes of cytotrophoblasts?syncytiotrophoblasts and deciduas were increased in spontaneous abortion by comparision with their counterpants in surgical aspiration ( P 0.05, P 0.01) , and both villi and decidua bcl 2/bax ratios were decreased compared with their counterparts in surgical aspiratio ( P 0.05, P 0.01), which was in consist with apoptosis. Conclusion Proliferation and apoptosis might play crucial roles in embryonic development and wastage during the first trimester of normal pregnancy. Apoptisis of a large population of cells in villi and deciduae might be the ultimate cause of morpholegical changes, and then prevent the development of human conceptus.