Plasma volume, umbilical artery Doppler flow, and antepartum fetal heart testing in high-risk pregnancies

The purpose of this clinical study is to investigate the diagnostic value of plasma volume (PV), nonstress test (NST), contraction stress test (CST), and umbilical artery Doppler (UAD) in detecting fetal compromise in 81 patients (83 fetuses) at risk for fetal growth retardation. Neither PV nor UAD studies were used in the clinical management. There were two stillbirths and three neonatal deaths for a perinatal mortality of 6%. Twenty-seven infants (32.5%) were small for gestational age (SGA), seven (8.6%) had cord pH 7.20 or less, and five (6.2%) had 5-minute Apgar scores less than 7. Overall, PV had the highest sensitivity and NST the highest specificity regarding delivery of SGA infants. The positive and negative predictive values for infants with low cord pH and low Apgar scores were similar among the various tests. There were nine fetuses with zero or reverse diastolic flow: seven were SGA (four perinatal deaths) and all of them had both nonreactive NST and positive CST. The other two infants were appropriate for gestational age with all other tests being normal. Antepartum fetal heart rate testing appears to be similar to other tests in predicting poor fetal outcome in high-risk pregnancies.