Histomorphometry of the human placenta in maternal preeclampsia.

The placentas of five mothers with severe preeclampsia who gave birth to moderately growth-retarded term infants were compared to a group of placentas collected from mothers who had uncomplicated pregnancies and normal term infants who were appropriate for gestational age. This study demonstrated that, on a quantitative histologic basis, the placentas of the preeclamptic mothers were morphologically very similar to the control placentas in terms of weight, parenchymal and cellular content, and surface areas of exchange between mother and fetus. The findings of this study support the hypothesis that, in preeclampsia not associated with severe intrauterine growth retardation, the perinatal morbidity associated with this condition is probably related more to some alterations in uteroplacental and, possibly, umbilical blood flows than to significant changes in placental structure and function. This may be due to compensatory repair mechanisms and extensive functional reserve capacities in these placentas.