EP18.01: Clinical and Doppler Predictors of Adverse Perinatal Outcomes in Late Onset Fetal Growth Restriction

To identify the clinical features and the Doppler findings associated with adverse perinatal outcomes in late-onset fetal growth restriction (FGR). Single centre study which included non-anomalous singleton pregnancies complicated by late-onset FGR, as defined either by abdominal circumference (AC) or estimated fetal weigth (EFW) below the 10th percentile for the gestation or by a reduction of the longitudinal growth of the AC. Ultrasound (US) follow up included the assessment of the fetal growth and of the Doppler parameters including umbilical artery (UA), middle cerebral artery, cerebroplacental ratio (CPR) and uterine arteries (UtA). Abnormal Doppler was defined either by CPR <5th centile or UA PI > 95th percentile or by mean UtA PI > 95th percentile for the gestation. Clinical and Doppler features at last scan were analysed and related to adverse perinatal outcomes. 236 cases were included, among whom 52 showed abnormal UtA PI, while 38 had abnormal UA PI and 74 had abnormal CPR at last US scan before delivery. Abnormal Doppler findings were associated with earlier gestational age at delivery (37+4+1+5 vs 38+6+1+2, p < 0.001), lower birthweight percentile (7.8 + 9.7 vs 13.4 + 13.4, p < 0.001) and with higher rate of NICU admission (32.5% vs 11.6%, p < 0.001) and composite adverse perinatal outcome (14.0% vs 6.5%, p 0.047). The gestational age at birth proved to be the only independent predictor of neonatal hypoglicemia (OR 0.735, 95% CI 0.568-0.953, p 0.02), neonatal intensive care unit (NICU) admission (OR 0.354, 95% CI 0.248-0.505) and composite adverse perinatal outcome (OR 0.647, 95% CI 0.499-0.840), while mean UtA PI > 95th percentile was the only independent predictor of birthweight below the 10th percentile (OR 2.147, 95% CI 1.038-4.441, p 0.039). Abnormalities in the maternal and fetal Doppler are associated with low gestational age at delivery and low birthweight, however the gestational age at delivery seems to be the strongest independent predictor of adverse perinatal outcomes in late-onset FGR.