Doppler ultrasonographic evaluation of abnormal pregnancies in the first trimester.

Doppler examination of uteroplacental vessels was performed in the first trimester of pregnancy in 111 women with a normal pregnancy outcome and in 10 women with pregnancies that had or subsequently failed due to anembryonic pregnancy (N = 4), missed abortion (N = 1), subsequent spontaneous abortion of live fetus (N = 2), and ectopic pregnancy (N = 3). Flow velocity waveforms (FVWs) were obtained three times by the same observer from subplacental vessels just within the myometrium. The Resistance Index (RI) of the FVWs was compared with the values obtained from 73 uncomplicated pregnancies and 38 women with threatened miscarriage and normal outcome. There was no apparent difference in the values for RI in the 10 patients whose pregnancies had failed, although the 3 live ectopic pregnancies studied had higher values. Although these studies may improve our understanding of the pathophysiology of early placentation, they are unlikely to be of value in the diagnosis of early pregnancy failure.