Intervillous and Spiral Artery Flows in Normal Pregnancies between 5 and 10 Weeks of Amenorrhea Using Color Doppler Ultrasonography

Abstract

In all cases, between 5 and 10 weeks, slow and continuous nonpulsatile intrachorionic flow could be detected, whereas pulsatile flow was detected in spiral arteries. The true nature of this early intervillous circulation remains to be determined.