O6. Uterine artery Doppler in a risk population: What’s its role in the prediction of small for gestational age fetuses?

Objective: The aim of this retrospective study was to assess the role of uterine artery (UtA) Doppler velocimetry in the prediction of small for gestational age (SGA) fetuses in a high risk population. Methods: A population of 145 singleton high risk pregnancies was evaluated with serial UtA Doppler performed within 23 weeks (I UtADoppler) and between 23 and 30 weeks’ gestation (II UtA Doppler). Risk population was composed by women with chronic hypertension or with a previous pregnancy complicated by one of the following: preeclampsia, stillbirth, abruptio placentae, small for gestational age newborns. The association between an abnormal UtA velocimetry (Resistance Index > 0.58 and/or bilateral notch) and the probability to develop SGA fetuses was analysed. SGA fetuses were diagnosed on the base of ultrasonographic measurement of abdominal circumference below the 10 centile. Therapy with low-dose aspirin and/or Low Weight Molecular Heparin was prescribed according with a clinical protocol. Results: Gestational age at delivery, mean birth weight, abnormal UtA Doppler and Umbilical artery Doppler were significantly different between SGA fetuses and not SGA fetuses (Table 1). Particularly 30% of SGA fetuses with an abnormal UtA Doppler had also an abnormal Umbilical artery Doppler (defined as a Pulsatility Index >95 centile). Logistic regression analysis showed that only the abnormal UtA Doppler test performed between 23 and 30 weeks’ gestation independently correlated with SGA fetuses, otherwise ASA was a significant protective factor for SGA fetuses (Table 2). Persistence of abnormal UtA Doppler was associated with a statistically higher rate of SGA. Conclusion: An abnormal UtA Doppler in the late second or early third trimester remained the variable significantly related with SGA fetuses; therefore UtA Doppler evaluation between 23 and 30 weeks could be useful for the management of high risk population. ASA was a significant protective factor for intrauterine growth.