P28.07: The prediction of adverse neonatal outcome is improved by longitudinal analysis of fetal biometric parameters and uterine artery Doppler velocimetry

To assess the value of single and serial fetal biometry by ultrasound (US) and Doppler velocimetry for the prediction of adverse neonatal outcomes. Retrospective analysis of 3,605 women with singleton pregnancies and ≥2 US scans at <37 weeks (16,942 scans). Primary outcomes: five-minute Apgar score <5; acidemia at birth; individual or combined adverse respiratory outcome (apnea, mechanical ventilation, and bronchopulmonary dysplasia); adverse neurological outcome (periventricular leukomalacia/intraventricular hemorrhage); necrotising enterocolitis (NEC); and neonatal sepsis. The mean and standard deviation across gestation of the fetal abdominal (AC) and head circumferences (HC), biparietal diameter (BPD), femur length (FL), estimated fetal weight (EFW), and mean uterine artery pulsatility index (MUAPI) were calculated by linear mixed-effects models. Single biometry (SB) outcome prediction was based on Z-scores of US parameters at the last available scan before gestational-age cut-offs 28, 32, and 37 weeks. For longitudinal analysis (LA), outcome prediction was based on the projected US parameter values at 40 weeks of gestation from all available measurements before each gestational-age cut-off. High MUAPI and reduced FL at the last US scan or projected from longitudinal screening at <28 weeks were associated with increased risk of apnea [SB: OR: 3.0 (1.4-6.5); LA: OR: 5.5 (2.8-10.9)]. Low AC and low EFW were associated with increased risk of mechanical ventilation when estimated at <28 weeks [SB: OR: 2.3 (1.3-3.8); LA: OR: 2.5 (1.5-4)] and at <32 weeks [SB: OR: 3.3 (2.1-5.2); LA: OR: 2.4 (1.5-3.8)]. Longitudinal screening linked high projected MUAPI with NEC [OR: 5.0 (2.0-12.1) and acidemia [OR: 2.3 (1.2-4.2)] from measurements obtained at <28 and <37 weeks, respectively. Longitudinal analysis of fetal biometric parameters and MUAPI increases the prediction of adverse neonatal outcome as compared to data obtained from the last available US scan.