The ultrastructural demonstration of placental phospholipids in preterm, term and eclamptic pregnancies.

Using a technique for the retention and visualization of aqueously soluble phospholipids the localization of phospholipids has been studied in placentae from preterm, term, and eclamptic pregnancies. Phospholipid accumulations at 32 weeks appear solely in the syncytiotrophoblast but as gestation increases phospholipids are found in an increased number of tissue compartments. By term, granules are seen in syncytiotrophoblast, cytotrophoblast, capillary endothelium, and the subtrophoblastic stroma. Two placentae from eclamptic pregnancies at 32-weeks demonstrate phospholipid localizations very similar to those found in the normal placenta at term. Additional non-straining lipid inclusions are seen within vascular pericytes in placentae from patients with eclampsia. The findings observed in the 32-week placentae from eclamptic pregnancies may be due to accelerated phospholipid metabolism, synthesis, or storage.