<正> Objective: To investigate a possible role of apoptosis in the pathophysiologic mechanisms of PIH （ pregnancy-induced hypertension syndrome）. Methods: In this study

placental samples were obtained from 16 uncomplicated third-trimester pregnancies and from 16 cases of PIH. We used light microscopy

electron microscopy to identify apoptosis. Light microscopy was used to quantify their incidence of apoptosis. Electron microscopy was used to confirm the occurrence of apoptosis. Results: Apoptosis has been conclusively demonstrated within human third-trimester placental tissue. Medians and interquartile ranges of normal placenta （n = 16） was 0. 12% （0. 08% -0. 19% ） ; Medians and interquartile ranges of PIH group （n = 16） was 0. 37% （0. 15% -0.49% ）. Compared to normal placentas

the incidence of apoptosis was higher in placentas from gestations complicated by PIH （ P < 0. 05

T’-test）. Conclusion: Placental apoptosis increases significantly in PIH

and it may play a role in the pathophysiologic mechanisms