Is it time to reassess the risk for the growth-retarded fetus with normal Doppler velocimetry of the umbilical artery?

OBJECTIVE

Previous studies demonstrate an association between abnormal umbilical artery Doppler velocimetry and the birth of a small-for-gestational-age infant and between abnormal result and adverse neonatal outcome. The hypothesis is that preterm growth-retarded infants with normal antenatal velocimetry have outcomes similar to other preterm infants, whereas preterm small-for-gestational-age infants with abnormal Doppler results define a subgroup with increased morbidity.

STUDY DESIGN

For 100 live-born infants, at risk for fetal growth retardation and undergoing antenatal Doppler and targeted ultrasonographic examinations, we assessed a number of complete neonatal outcome parameters.

RESULTS

Ten neonatal deaths occurred in the study population, seven with abnormal Doppler results and three with normal Doppler results. Of the 90 surviving infants, gestational age at delivery was not different between the Doppler normal and abnormal neonates, whereas birth weight (1714 gm vs 1379 gm) was higher in the Doppler normal group (p = 0.006). The presence of intraventricular hemorrhage (20% vs 6%) was higher in the abnormal group (p = 0.05). Abnormal Doppler results defined an infant group destined for prolonged hospitalization, mean intensive care days (21 vs 9), and special care nursery days (25 vs 9). Thirty-eight percent of small-for-gestational-age babies had a normal Doppler result. Analysis of variance indicated small-for-gestational-age infants with abnormal Doppler results (n = 20) had a mean intensive care unit stay of 31 days, significantly different (p = 0.005) from small-for-gestational-age infants with normal Doppler results (n = 14), non-small-for-gestational-age infants with abnormal results (n = 21), and non-small-for-gestational-age infants with normal results (n = 35) whose mean intensive care unit stays were 14, 12, and 7 days, respectively. Gestational age at delivery (33.0 weeks) was not different among these groupings, not accounting for the observed differences.

CONCLUSION

Normal antenatal velocimetry defines a distinct subgroup of preterm small-for-gestational-age infants at less risk for prolonged hospitalization compared with those with abnormal velocimetry.