Obstetric and pediatric growth charts for the detection of fetal growth restriction and neonatal adverse outcomes in preterm newborns before 34 weeks of gestation

Abstract

Introduction Identification of fetal growth-restricted (FGR) infants depends on the fetal or newborn charts used to identify them. We aimed to compare the prenatal and postnatal diagnosis of FGR and their ability to predict adverse perinatal outcomes. Methods Observational retrospective cohort study of 95 consecutive mother–infant pairs with preterm birth between 24 and 34 weeks (study period: January 2014 to December 2015). Prenatal sonographic diagnosis of FGR, based on customized fetal growth standards and fetal Doppler, was compared with the postnatal diagnosis of FGR based on a birthweight < 3rd percentile according to newborn charts (International Newborn size references for the Intergrowth twenty-first century program, and Olsen’s charts). Neonatal mortality and adverse neonatal outcomes were compared among groups. Results In 23/95 (24%) cases a prenatal diagnosis of early FGR was made. Postnatal FGR was confirmed in 11/23 (48%) cases using Olsen’s charts and 8/23 (35%) using Intergrowth 21st charts. One postnatal FGR case was missed by prenatal ultrasound. Bronchopulmonary dysplasia, sepsis and hypoglycemia were more frequent in pre- and postnatal FGR versus non-FGR. After adjusting for gestational age and sex, only an increased relative risk of hypoglycemia (2.0, 95%CI 1.0–2.8) was observed in infants with pre- and postnatal FGR diagnosis. Nonsignificant differences on neonatal outcomes were identified between prenatal FGR cases with normal birthweight and the non-FGR group. Conclusion Only prenatal FGR cases in which a birthweight below the third percentile is confirmed by means of postnatal charts (Olsen or Intergrowth standard) are at higher risk of adverse postnatal outcome.