EP08.01: Prediction of large‐for‐gestational‐age neonates at 35–37weeks

Large-for-gestational-age (LGA) neonates are at increased risk of adverse outcomes. Identifying women at risk of delivering an LGA neonate offers a window of opportunity to mitigate these outcomes. This study aimed to evaluate the performance of sonographic biometric and Doppler parameters, assessed at a routine third trimester scan, in combination with maternal characteristics, in predicting LGA neonates. This was a cohort study of low-risk singleton pregnancies undergoing routine ultrasound between 35+0 and 37+6 weeks. Demographic characteristics, estimated fetal weight (EFW) and abdominal circumference (AC) centiles, the Pulsatility Index (PI) of the Umbilical Artery (UA), Middle Cerebral Artery (MCA), and Uterine Artery (UtA) were evaluated. The Cerebroplacental ratio (CPR) was calculated. All indices were converted into Multiples of the Median (MoM). Multivariable logistic regression analysis was performed. Receiver-operating curves (ROC) were created to determine predictors of LGA neonates (birthweights >90th centile) and LGA neonates with adverse outcomes (Intrauterine death, Neonatal death, and Neonatal Intensive Care Unit Admission). A total of 14,161 pregnancies were included. EFW centile (adjusted odds ratio (aOR) 1.12, 95% CI, 1.11-1.12, p < 0.001), AC centile (aOR 1.1, 95% CI, 1.08-1.09, p < 0.001), UA PI (aOR 0.34, 95% CI, 0.19-0.61, p < 0.001), MCA PI (aOR 1.98, 95% CI, 1.3-3.0, p = 0.002) CPR (aOR 2.2, 95% CI, 1.57-3.20, p < 0.001), UtA PI (aOR 0.6, 95% CI, 0.42-0.86, p = 0.006) and gestational age at birth (aOR 1.4, 95% CI, 1.3-1.51, p < 0.001) were independent predictors of LGA > 90th centile. AC centile (aOR 1.1 (95% CI 1.02-1.16) p = 0.007 was an independent predictor of LGA with adverse outcomes. The combination of EFW centile, CPR, and UtA PI MoM was associated with an Area Under the Curve of 0.89 (95% CI 0.88-0.9) p < 0.001. In an unselected population, the UA PI, MCA PI, CPR, and UtA PI are independent predictors of LGA and adverse perinatal outcomes. The combination of these parameters can reliably predict LGA outcomes with a high degree of accuracy.