Duplex Doppler sonography of the umbilical arteries: predictive value in IUGR and correlation with birth weight.

ABSTRACT

Forty-three women with either clinically high-risk singleton pregnancies or a predicted fetal weight less than the 10th percentile were studied in their third trimester by duplex Doppler sonography of the free umbilical artery to assess the associations between umbilical arterial flow resistance and intrauterine growth retardation (IUGR) and birth weight. Test criteria included the greatest (GRI), mean (MRI), and least (LRI) resistive index. The criterion with the strongest association with IUGR (p = 0.001) was the parameter of the LRI predicting IUGR). Linear regression analysis showed a nonsignificant correlation between RI and percentile birth weight, with r2 = 0.05 and p = 0.131. While significant associations can be shown between RI and IUGR, the clinical use of the results of this test should reflect the imprecise nature of these correlations.