[Uteroplacental vascularization].

The intervillous space is considered as receiving the most important part of the uterine flow input (> 90%), reaching the placenta through the modified spiral arteries network. The low vascular resistance detected on the uterine arteries is thought to be due to the presence of the placental shunt. Using a 3D Colour Doppler technology (ATL 5000), a complex anastomotic and intra-myometrial network has been detected. This vascular network is always detected during the first 48 hours of after delivery. During this time, the placenta has been removed, the uterine muscle is contracted, a low resistance of the uterine flow is systematically detected. A extraplacental vascular component must be considered as taking a functional part in the foeto-maternal exchanges.