Journal of Perinatology (2020) 40:704–714 https://doi.org/10.1038/s41372-020-0658-5 REVIEW ARTICLE “Extrauterine growth restriction” and “postnatal growth failure” are misnomers for preterm infants Tanis R. Fenton 1,2 ● Barbara Cormack 3 ● Dena Goldberg 4 ● Roseann Nasser 5 ● Belal Alshaikh 1,6 ● Misha Eliasziw 7 ● William W. Hay 8 ● Angela Hoyos 9 ● Diane Anderson 10 ● Frank Bloomfield 3 ● Ian Griffin 11 ● Nicholas Embleton 12 ● Niels Rochow 13 ● Sarah Taylor 14 ● Thibault Senterre 15 ● Richard J. Schanler 16 ● Seham Elmrayed 1 ● Sharon Groh-Wargo 17 ● David Adamkin 18 ● Prakesh S. Shah 19 Received: 9 August 2019 / Revised: 2 March 2020 / Accepted: 11 March 2020 / Published online: 25 March 2020 © The Author(s), under exclusive licence to Springer Nature America, Inc. 2020 Abstract Preterm infants are increasingly diagnosed as having “extrauterine growth restriction” (EUGR) or “postnatal growth failure” (PGF). Usually EUGR/PGF is diagnosed when weight is <10th percentile at either discharge or 36–40 weeks postmenstrual age. The reasons why the phrases EUGR/PGF are unhelpful include, they: (i) are not predictive of adverse outcome; (ii) are based only on weight without any consideration of head or length growth, proportionality, body composition, or genetic potential; (iii) ignore normal postnatal weight loss; (iv) are usually assessed prior to growth slowing of the reference fetus, around 36–40 weeks, and (v) are usually based on an arbitrary statistical growth percentile cut-off. Focus on EUGR/PGF prevalence may benefit with better attention to nutrition but may also harm with nutrition delivery above infants’ actual needs. In this paper, we highlight challenges associated with such arbitrary cut-offs and opportunities for further refinement of understanding growth and nutritional needs of preterm neonates. Introduction Researchers and clinicians increasingly have been using the phrases “extrauterine growth restriction” (EUGR) or “postnatal growth failure” (PGF) as an outcome metric for preterm infants [1] despite these phrases being problematic in both overidentifying infants as not growing adequately and not identifying those who are actually failing to grow well. Usually EUGR/PGF is diagnosed when a preterm infant’s weight is below the 10th percentile * Tanis R. Fenton tfenton@ucalgary.ca 1 Community Health Sciences, Institute of Public Health, Alberta Children’s Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada 2 Nutrition Services, Alberta Health Services, Calgary, AB, Canada 3 Liggins Institute, University of Auckland, Auckland, New Zealand 4 Carilion Clinic, Roanoke, VA, USA 5 Saskatchewan Health Authority, Nutrition and Food Services, Regina, SK, Canada 6 Pediatrics, University of Calgary, Calgary, AB, Canada 7 Public Health and Community Medicine, Tufts University, Boston, MA, USA 8 University of Colorado, Denver, CO, USA 9 Clínica del Country, Universidad el Bosque, Bogotá, Colombia 10 Pediatrics, Baylor College of Medicine, Houston, TX, USA 11 Clinical and Translational Research, Biomedical research Institute of New Jersey, Cedar Knolls, NJ, USA 12 Newcastle Hospitals NHS Foundation Trust, Royal Victoria Infirmary, Newcastle upon Tyne, UK 13 Pediatrics, McMaster University, Hamilton, ON, Canada 14 Pediatrics, Yale School of Medicine, New Haven, CT, USA 15 Neonatology, University of Liege, CHU de Liege, Liege, Belgium 16 Neonatal Services, Cohen Children’s Medical Center, Northwell Health, Zucker School of Medicine at Hofstra, New York, NY, USA 17 Pediatrics and Nutrition, Case Western Reserve University, Cleveland, OH, USA 18 Pediatrics, University of Louisville, Louisville, KY, USA 19 Paediatrics and Institute of HPME, University of Toronto, Mount Sinai Hospital, Toronto, ON, Canada 1234567890();,: 1234567890();,: