Quantitative structural studies on human placentas associated with pre-eclampsia, essential hypertension and intrauterine growth retardation.

Placentas from pregnancies complicated by pre-eclampsia, essential hypertension, hypertension complicated by pre-eclampsia and from normotensive pregnancies resulting in the birth of a singleton small-for-dates (SFD) infant have been studied by quantitative morphometry. The findings have been compared with those from placentas of uncomplicated pregnancies. The placentas from pregnancies complicated by pre-eclampsia and those resulting in a SFD baby had a significantly lower total volume, volume of parenchyma and villous surface area when compared with normal pregnancies of comparable gestation. They also had an increase in areas of multiple infarction and in the volume proportions occupied by fetal capillaries. The placentas from women with essential hypertension uncomplicated by pre-eclampsia were as large as those from normal pregnancies and the villous surface areas were as high. Villous surface area measurements in the different groups were related to gestation and to fetal weight.