The International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st) is a global, multidisciplinary network of more than 300 researchers and clinicians from 27 institutions in 18 countries, coordinated from the University of Oxford. The consortium has, over the years, produced various growth standard recommendations which have been adopted globally.

The latest standards are for preterm growth, and their distribution and training is being supported by the Family Larsson-Rosenquist Foundation (FLRF). The globally validated preterm infant growth standards, feeding protocols and tools and practical training materials are freely available to clinicians, researchers and policymakers – putting them into practice can help improve the health of preterm infants worldwide.


To meet the need for international growth standards to measure and improve outcomes and clinical care for preterm infants, INTERGROWTH-21st embarked on a project – under the leadership of professors José Villar and Stephen Kennedy, and with a contribution of approximately USD 2.8 million from FLRF – to create new resources specific to preterm infants. The resulting standards, tools and training materials complement existing standards for pregnancy and newborn infants, with the aim of providing continuity from conception until five years of age.

Until now, in the INTERGROWTH-21st project, growth and feeding protocols for preterm infants had been missing. The measurement of preterm growth was based upon expected fetal growth whilst in utero. These new standards of care can support optimal growth of preterm infants and help clinicians and parents avoid overfeeding, reduce the risk of childhood overweight and obesity, and improve the early detection of infants with suboptimal growth. The INTERGROWTH-21st project also has the potential to alter World Health Organization policy in constructing and presenting preterm growth charts.

“We have the opportunity, as part of this ground-breaking project, to translate research results to practice; hence, improve the overall health, nutritional status and development of preterm infants globally.” – José Villar, MD, MPH, MSc, FRCOG, Professor of Perinatal Medicine, Nuffield Department of Women’s & Reproductive Health, University of Oxford; Co-Director, Oxford Maternal & Perinatal Health Institute (OMPHI), Green Templeton College

The new, practical international tools for researchers, clinicians and policymakers include an online training module and practical support to aid their transition into practice. These standards, feeding protocols and clinical tools can make it easier to scale up adoption of the standards, and thus improve the health of preterm infants worldwide.

“Global adoption of these standards is a vital tool for promoting breastfeeding in neonatal units and infant clinics around the world so as to improve the survival and health of preterm infants.” – Stephen Kennedy, MA, MD, MRCOG, Professor of Reproductive Medicine; Head, Nuffield Department of Women’s & Reproductive Health, University of Oxford; Co-Director, Oxford Maternal & Perinatal Health Institute (OMPHI), Green Templeton College.

The INTERGROWTH-21st Project’s growth monitoring, educational and feeding resources have been translated into several languages, including English, Spanish, Italian, Russian and Portuguese, and the training toolkit is expanding. 

By the close of 2021:
• Over 357,00 tools had been downloaded in 195 countries
• Over 50,000 preterm postnatal growth standards had been downloaded in 128 countries
• Over 35,794 courses on preterm postnatal growth and feeding recommendations had been taken, in a variety of languages including English, Italian, Portuguese, Russian and Spanish 
• A worldwide network of more than 400 hospitals and health institutions is using the preterm postnatal growth standards and feeding recommendations

References and further reading

Green LJ, Kennedy SH, Mackillop L, Gerry S, Purwar M, Staines Urias E, et al. International gestational age-specific centiles for blood pressure in pregnancy from the INTERGROWTH-21st Project in 8 countries: A longitudinal cohort study. PLoS Med. 2021;18(4):e1003611. DOI: 10.1371/journal.pmed.1003611

Ohuma EO, Villar J, Feng Y, Xiao L, Salomon L, Barros FC, et al. Fetal growth velocity standards from the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. Am J Obstet Gynecol. 2021;224(2):208.e1-208.e18. DOI: 10.1016/j.ajog.2020.07.054

Fernandes M, Villar J, Stein A, Staines Urias E, Garza C, Victora CG, et al. INTERGROWTH-21st Project international INTER-NDA standards for child development at 2 years of age: an international prospective population-based study. BMJ Open. 2020;10(6):e035258. DOI: 10.1136/bmjopen-2019-035258

Drukker L, Staines-Urias E, Villar J, Barros FC, Carvalho M, Munim S, et al. International gestational age-specific centiles for umbilical artery Doppler indices: a longitudinal prospective cohort study of the INTERGROWTH-21st Project. Am J Obstet Gynecol. 2020;222(6):602.e1-602.e15. DOI: 10.1016/j.ajog.2020.01.012

Hirst JE, Knight HE, Ohuma EO, Dwyer T, Hennig BD, Papageorghiou AT, et al. Social gradient of birthweight in England assessed using the INTERGROWTH-21st gestational age-specific standard. Arch Dis Child Fetal Neonatal Ed. 2019;104(5):F486–92. DOI: 10.1136/archdischild-2018-315295

Villar J, Giuliani F, Figueras-Aloy J, Barros F, Bertino E, Bhutta ZA et al. Growth of preterm infants at the time of global obesity. Arch Dis Child. 2019 Aug;104(8):725-727. DOI: 10.1136/archdischild-2018-315006.

Villar J, Giuliani F, Barros F, Roggero P, Coronado Zarco IA, Rego MAS et al. Monitoring the Postnatal Growth of Preterm Infants: A Paradigm Change. Pediatrics. 2018 Feb;141(2). pii: e20172467. DOI: 10.1542/peds.2017-2467.

Villar J, Giuliani F, Bhutta ZA, Bertino E, Ohuma EO, Ismail LC et al. Postnatal growth standards for preterm infants: the Preterm Postnatal Follow-up Study of the INTERGROWTH-21st Project. Lancet Glob Health. 2015 Nov;3(11):e681-91. DOI: 10.1016/S2214-109X(15)00163-1.

Villar J, Ismail L, Victora C, Ohuma E, Bertino E, Altman D et al. International standards for newborn weight, length, and head circumference by gestational age and sex: the Newborn Cross-Sectional Study of the INTERGROWTH-21st Project. Lancet. 2014 Sep 6;384(9946):857-68. DOI: 10.1016/S0140-6736(14)60932-6.

Bhutta ZA, Giuliani F, Haroon A, Knight HE, Albernaz E, Batra M et al. Standardisation of neonatal clinical practice. BJOG. 2013 Sep;120 Suppl 2:56-63, v. DOI: 10.1111/1471-0528.12312.

Villar J, Altman DG, Purwar M, Noble JA, Knight HE, Ruyan P et al. The objectives, design and implementation of the INTERGROWTH-21st Project. BJOG. 2013 Sep;120 Suppl 2:9-26, v. DOI: 10.1111/1471-0528.12047.