Fenton Third‐Generation Growth Charts of Preterm Infants Without Abnormal Fetal Growth: A Systematic Review and Meta‐Analysis

BACKGROUND: Experts recommend assessing preterm infant growth against fetal growth patterns. However, obtaining accurate estimates of healthy fetal growth from preterm infants is challenging as many had intrauterine faltering growth. OBJECTIVES: To improve preterm infant growth assessments by developing Fenton third-generation sex-specific preterm growth charts based on anthropometric distributions of preterm infants without abnormal fetal growth. We also aimed to evaluate the consistency of the new charts' growth velocities. DATA SOURCES: From the last search for the 2013 Fenton growth charts to November 2024, MEDLINE and EMBASE databases, grey literature, as well as US Vital statistics and iNeo Consortium. STUDY SELECTION AND DATA EXTRACTION: We followed systematic review methodology to identify population-based sex-specific anthropometric estimates of preterm cohorts without abnormal fetal growth beginning ≤ 24 weeks of gestation. Specified a priori, outcomes included newborn sex-specific estimates of birthweight, length, and head circumference. SYNTHESIS: We followed PRISMA guidelines. Literature screening and quality assessment were performed in duplicate. We harmonised weight, length, and head circumference weighted-average meta-analyses with the World Health Organization growth standard and rescaled the charts' x-axis from completed gestational weeks to exact gestational age (weeks and days). RESULTS: Seven studies from 15 countries (Australia, Brazil, Canada, China, Finland, Israel, Italy, Japan, Netherlands, New Zealand, Sweden, Switzerland, Spain, United Kingdom and United States) were included, representing 4.8 million births 22-42 weeks of gestation. 174,184 were < 30 weeks gestational age. The Fenton third-generation preterm growth charts' weights showed improved growth velocity across percentiles with consistent declines for weight, length and head circumference velocity as post-menstrual age increased. The birthweight meta-analysis curves had similar shapes to fetal ultrasound estimates. CONCLUSIONS: The Fenton third-generation preterm infant growth chart curves demonstrate improved and more uniform slopes across percentiles and closer alignment with fetal ultrasound estimates, offering a growth standard for preterm infants. PROSPERO REGISTRATION: CRD42024589756.