Doppler evaluation of the fetoplacental circulation in the latent phase of preterm premature rupture of membranes

Abstract

Blood velocity waveform analysis by pulsed Doppler ultrasonography in preterm premature rupture of membranes is described. Reduced amounts of amniotic fluid did not impair determination of the resistance indices from the umbilical artery. Good results were obtained from the internal carotid artery in 82% of cases. Failure in measurements at the internal carotid artery occurred when fetal head engagement prevented good study planes. Ninety-three percent of umbilical artery determinations fell within the normal limits for our control population as did 89.2% of those at the internal carotid artery. No differences in the resistance indices could be attributed to the length of the latent period in prematurely ruptured membranes or subclinical chorioamnionitis. Therefore, if a mother or fetus has an underlying condition that affects fetoplacental circulation, the resulting abnormal blood velocity waveform should reflect this condition rather than the effect of ruptured membranes.