The efficacy of umbilical artery blood flow velocity waveform to predict the perinatal outcome of term pregnancies with small for gestational age / 대한산부인과학회지

ABSTRACT

OBJECTIVE: To investigate whether umbilical artery Doppler blood flow velocity waveform is effective in predicting perinatal outcome of term pregnancies with small for gestational age (SGA). METHODS: A total of 381 patients at 37~41 weeks of gestational age (GA) who received antenatal umbilical artery Doppler blood flow test and delivered singleton SGA infants. The ratio of peak-systolic to end-diastolic (S/D) blood flow velocities in the umbilical artery was measured in each patient. The patients were divided into a normal group (n=307) with a S/D ratio equal to or less than 3.0, and an abnormal group with a S/D ratio of greater than 3.0 (n=74). These groups were comparatively analysed with respect to maternal characteristics and neonatal outcomes. Results: There were no significant differences between the two groups in mean maternal age, gestational age at the time of delivery, and cesarean section rate due to fetal distress. There was significantly increased incidence of hypertensive disorders in pregnancy in the abnormal S/D ratio group. And the abnormal S/D ratio group showed lower neonatal birthweight, higher incidence of admission to neonatal intensive care unit (NICU), and longer stay in neonatal intensive care unit. According to linear regression, in pregnancies complicated by SGA, abnormal S/D ratio was still a risk factor for low birthweight even after controlling for the incidence of hypertension. Conclusion: In term pregnancies accompanied by SGA, abnormal umbilical artery S/D ratio is an independent predictor of neonatal birth weight, incidence of admission to NICU, and NICU stay.