The aim of this study was to investigate the mechanisms involved in abortion by evaluating immunohistochemical expression of Bcl-2, an apoptosis inhibitor, and Ki-67, a proliferation marker, and correlating their expression in the fetal trophoblasts and maternal deciduas from abortion material with those in normal placenta.Materials and methods
The material of this work consisted of deciduas and chorionic villi from 30 cases of early spontaneous abortion (the abortion group) and 10 normal placenta (the control group). Hematoxylin and eosin-stained sections from all cases were re-evaluated and further stained immunohistochemically using antibodies against Ki-67 and Bcl-2.Results
Ki-67 expression in both cytotrophoblastic cells and deciduas was found to be significantly decreased in abortions compared with normal placenta. Bcl-2 expression in syncytiotrophoblastic cells covering the villous stroma was decreased in abortions compared with their expression in normal placenta. Statistically significant correlation was found between Ki-67 and BCL-2 scores (P=0.000).Conclusion
Proliferation rate was decreased in fetal villous cytotrophoblasts and maternal deciduas in abortions. Moreover, loss of Bcl-2 expression in syncytiotrophoblasts may cause abortion in a subset of cases.