Measurement of the mass of syncytiotrophoblast in a range of human placentae using an image analysing computer.

Placentae from normal term pregnancies, from "normal" preterm pregnancies and from pregnancies complicated by pre-eclampsia have been analysed by computerized histometry. An immunoperoxidase technique was used to stain specifically human placental lactogen in the syncytiotrophoblast. The percentage and mass of syncytiotrophoblast were measured using an image analysing computer. The percentage of syncytiotrophoblast was found to be remarkably constant throughout gestation. Strong evidence was found that a linear relationship exists between syncytiotrophoblast mass and gestation period and that on average pre-eclampsia placentae have a lower percentage and a reduced mass of syncytiotrophoblast.