Obstetric and pediatric growth charts for the detection of late-onset fetal growth restriction and neonatal adverse outcomes

Late-onset fetal growth restriction (FGR) has heterogeneous prenatal and postnatal diagnostic criteria. We compared the prenatal and postnatal diagnosis of late-onset FGR and their ability to predict adverse perinatal outcomes.Retrospective cohort study of 5442 consecutive singleton pregnancies that delivered beyond 34 + 0 weeks. Prenatal diagnosis of FGR was based on customized fetal growth standards and fetal Doppler while postnatal diagnosis was based on a birthweight <3rd percentile according to newborn charts (Olsen's charts and Intergrowth 21st century programme). Perinatal outcomes were analyzed depending on whether the diagnosis was prenatal, postnatal or both.A total of 94 out of 5442 (1.7%) were diagnosed as late-onset FGR prenatally. Olsen's chart and Intergrowth 21st chart detected that 125/5442 (2.3%) and 106/5442 (2.0%) of infants had a birthweight <3rd percentile, respectively. These charts identified 35/94 (37.2%) and 40/94 (42.6%) of the newborns with a prenatal diagnosis of late-onset FGR. Prenatally diagnosed late-onset FGR infants were at a higher risk for hypoglycemia, jaundice and polycythemia. Both prenatally and postnatally diagnosed as late-onset FGR had a higher risk for respiratory distress syndrome when compared to non-FGR. The higher risks for intensive care admission and composite adverse outcomes were observed in those with a prenatal diagnosis of late-onset FGR that was confirmed after birth.Current definitions of pre- and postnatal late-onset FGR do not match in more than half of cases. Infants with a prenatal or postnatal diagnosis of this condition have an increased risk of neonatal morbidity even if these diagnoses are not coincident.