[Ultrastructural changes in the capillaries of the placenta during hypoxia].

To investigate early stages of hypoxia, the authors studied fetal capillaries of the terminal cilia in the placenta of women without clinical manifestations of fetal hypoxia in such pathologic states as protracted labor, uterine fibromyoma, late toxicosis of pregnancy. The capillaries are shown to have the same typical changes: the increase of nuclear volume, of the number of cytoplasmic organellae (mitochondria, cysternae of the granular endoplasmic reticula, polysomes and free ribosomes, pinocytic vesicules) and cytoplasmic appendages, which come into active contact with the blood cells. These changes are directed to normalization of oxygen and nutrient supply to the fetus.