Midtrimester preeclamptic toxemia in triploid pregnancies

Nineteen advanced triploid pregnancies reported in the literature are reviewed. In 8 of 14 pregnancies for which reliable data were available, severe preeclamptic toxemia (EPH gestosis) developed, most often from the 16th to the 24th week of gestation. In all the toxemic cases, the placenta was large for the stage of pregnancy, the placental coefficient was high (mean 0.83) and extensive areas of molar degeneration were present. Advanced triploid pregnancy is considered a further example of hyperplacentosis causing preeclamptic toxemia. The study of toxemic and nontoxemic advanced triploid pregnancies supports the assumption that hyperplacentosis, rather than being related to excessive placental size, is the expression of trophoblastic hyperactivity.