Histological and ultrastructural investigations of placenta villi in intrauterine growth restriction of fetuses (IUGR).

The investigations were carried out on five placentas derived from normal pregnancies and on the five placentas derived from the pregnancies with intrauterine growth restriction (IUGR) of fetuses. Semithin sections were stained with methylene blue and azure and estimated by light microscope. Ultrathin sections were stained according to the Reynold's method and estimated by the electron microscope. Two types of irregularity were observed: 1) lack of vessels with a concomitant increase of macrophage number in the stroma of villi, 2) an increased number of vessels and the presence in syncytiotrophoblast of a wide space near the basal membrane preventing the exchange between the maternal blood and the fetal blood.