OP20.13: The shift of umbilical‐portal watershed in the growth‐restricted fetus assessed by velocity measurement in the left portal vein

Abstract

the umbilical vein flow (UVF) is decreased in the IUGR fetus, but it has also been said that the decrease in the UVF occurs weeks before the decrease in the fetal growth can be measured. The aim of our study was to evaluate the usefulness of the umbilical vein blood flow as a predictor of intrauterine growth restriction in a low-risk population. Methods: Six hundred and thirty low-risk patients were routinely scaned during the third trimester between the 28th and 36th weeks of gestation. Estimated fetal weight (EFW), umbilical artery (UA) pulsatily index (PI), middle cerebral artery (MCA) PI and umbilical vein blood flow (UVBF) were measured. The ratio UVBF/head circumference (HC) was compared with neonatal birth weight. Predictive values, sensitivity and especificity for low birth weight were calculated. Results: Biometrical and Doppler parameters were successfully calculated in all fetuses. Sixty-six fetuses (10%) were found to be born small-for-gestational age. In these fetuses the ratio UVBF/HC was significantly lower when compared with the fetuses with an average-for-gestational age birth weight. The sensitivity and the specificity of the UVBF/HC for the detectection of low birth weight were 46% and 75%, respectively. Conclusions: The UVBF/HC could detect, during the routine thirdtrimester scan, the fetus at high risk for being small-for-gestional age. In these fetuses extra surveillance could be offered.