Bruner J P, Gabbe S G, Levy D W, Arger P H
Department of Obstetrics and Gynecology, Hospital of the University of Pennsylvania, Philadelphia.
South Med J. 1993 Jan;86(1):52-5. doi: 10.1097/00007611-199301000-00012.
Using continuous wave Doppler ultrasonography to measure umbilical artery flow velocity waveforms (FVWs) is a safe, noninvasive means of quantifying placental resistance to blood flow. Detection of abnormally elevated resistance to umbilical perfusion may identify pregnancies complicated by uteroplacental insufficiency. Use of this technique to identify high-risk pregnancies requires ready access to standard tables of normal FVW values obtained from well-defined populations under usual clinical conditions. We report measurements of the systolic-diastolic (S-D) ratio of the umbilical artery obtained between 16 and 43 weeks in 122 normal pregnancies. A gestational-age-adjusted table of normal values is presented.