Objective: To evaluate the umbilical and uterine arterial Doppler flow velocity waveform systolic to diastolic (S/D) ratios performed at 24-30 weeks gestation for predicting fetal growth retardation (IUGR).
Methods: A prospective double blind study was conducted in 118 cases of high risk singleton pregnant women. The umbilical and uterine arterial S/D ratios were measured at 24-30 gestational weeks and the pregnancy outcomes were followed up.
Results: The prevalence of IUGR in our study population was 16.9%. At 24-30 weeks gestation, the S/D ratio of both umbilical artery and uterine artery in IUGR pregnant women were significantly higher than those in normal pregnant women, while the fetal biometric measurements were normal in all the 118 cases. The sensitivity, specificity and positive predictive value of umbilical arterial S/D ratio to predict IUGR were 80.0%, 83.7% and 50.0% with a Kappa index of 0.51 at 24-30 weeks gestation. With lower sensitivity, specificity, positive predictive value and Kappa index (40.0%, 84.5%, 34.8% and 0.23 respectively), the uterine arterial S/D ratio had less predictive value.
Conclusions: The umbilical arterial Doppler flow velocity waveform S/D ratio may be an earlier predictor for screening of IUGR at 24-30 weeks gestation in high risk pregnant women with normal fetal biometric measurements.