ABSTRACT
The placenta has been implicated in the pathophysiology of preeclampsia. Preeclampsia is more common in multifetal gestations which have an increased placental mass compared to singleton pregnancies. Detecting the effects of preeclampsia on the availability of enzymes in the full term placenta. Two groups of placentae were taken from full term pregnant women immediately after labour, each consisting of ten placentae. The first group are placentae obtained from women having an uneventful pregnancy with no history of disease or complication [as a control group] while the second group consists of placentae obtained from women with a history of preeclampsia. The materials were obtained from Al-Batool and Al-Khansaa Teaching Hospitals in Mosul, between February and July [2006]. Significant histochemical changes were detected in the placentae of the second group when compared with those from the first group, such changes result from syncytial damage and destruction affecting the preeclamptic placentae, leading to the loss of alkaline phosphatase enzyme with an increase in the amount of the degenerating acid phosphatase enzyme