[Uterine spiral arteries of the human in gestosis, fetal growth retardation and postmaturity].

The uterine spiral arteries in humans were examined after a normal course of pregnancy and a pathological course with gestosis, fetal growth retardation and post-term birth. We found that the spiral arterioles in normal pregnancy underwent physiological changes, such as invasion of trophoblasts and decomposition of fibromuscular media and elastic tissue. Apart from the post-term birth, we detected in pathological pregnancies a narrowing of the vascular lumen by proliferation of the intima and often little or no physiological changes of the spiral arterioles in the myometrial segment. Compared to normal pregnancies, thrombogenic formation, swelling of the intima and infiltration of erythrocytes were more frequently observed in post-term births. The flow resistance of maternal blood is greater in cases of gestosis and fetal growth retardation than in normal pregnancies, since the uterine spiral arterioles exhibited a narrowing of the vascular lumen and little or no physiological changes of the vascular wall, and in post-term births also increased thrombogenic formation and swelling of the intima. The resulting decrease in uteroplacental blood flow could lead to a functional insufficiency of the placenta.