Microangiographic observations on the uterine and maternal placental vasculature in early human pregnancy

Abstract

Four patients at 12 to 16 weeks' gestation were admitted to the hospital for legal abortion and sterilization. Because of large uterine myomas, hysterectomy was performed. Three intact pregnant uteri thus obtained were successfully perfused through the arteries or veins with a barium sulfate suspension. The filled vascular compartments were studied with microangiography and histologic methods. Arterial perfusion freely filled all the myometrial vessels and the intervillous space and also demonstrated the wide thin-walled veins which drain the latter. Morphologic evidence suggests that these veins are important in transporting humoral substances from the fetoplacental unit to the myometrium. Venous perfusion did not lead to filling of the intervillous space, probably because the dilated veins within the myometrium and decidual plate produced increased intrauterine pressure.