An Oxford-led project aims to improve health outcomes for preterm babies worldwide.

Compared to term babies, those born small and/or prematurely are at greater risk of dying in the first few weeks of life and of developing health problems such as high blood pressure, diabetes and heart disease in adulthood. Tackling these problems on a global scale requires a reliable way of identifying impaired growth in the womb that manifests as small size for gestational age at birth. Doing so has not been possible until recently because of the lack of charts describing optimal growth that apply to all populations in the world.

INTERGROWTH-21st is a global, multidisciplinary project studying human growth and development from early pregnancy to two years of age. The programme is co-led by José Villar, Professor of Perinatal Medicine, and Stephen Kennedy, Professor of Reproductive Medicine, both from the University’s Nuffield Department of Obstetrics & Gynaecology, based at the John Radcliffe Hospital, Oxford.

The project adopted the same conceptual approach and design as the 2006 World Health Organization (WHO) study that produced international standards for term babies describing optimal growth from 0-5 years of age - the WHO Child Growth Standards. Despite the widespread acceptance and use of the WHO Child Growth Standards around the world, there is still a commonly held belief that certain populations, particularly in low and middle income countries, have small babies because of their genes, and not because they are exposed to adverse influences such as poor maternal nutrition and infection.

Fetal growth is a crucial period of development – the basics that will map the rest of your life.Professor José Villar

Professor Villar states, ‘Our hypothesis was that healthy, well-nourished women, free of disease, living in a clean environment and receiving good antenatal care would have babies that grow similarly inside the womb and achieve a similar size at birth. If this proved true, then it would be possible to produce a single set of international standards to assess the growth of all babies. Those babies not growing ‘healthily’ could then be reliably identified resulting in better and more targeted health care.’

The INTERGROWTH-21st Consortium collected data from mothers and their babies in Brazil, China, India, Italy, Kenya, Oman, the UK and the USA, and clearly demonstrated that healthy mothers do have healthy babies that grow similarly inside the womb and achieve a similar size at birth irrespective of their ethnicity. The resulting international standards perfectly match the existing WHO Child Growth Standards and now enable growth and development to be monitored in a consistent manner from early pregnancy to five years of age. To date, these standards have been downloaded in total over 60,000 times across virtually every country in the world.

The INTERGROWTH-21st Newborn Size Standards proved invaluable during the recent Zika virus epidemic. Once adopted by WHO, the standards helped to improve screening for microcephaly so that the Brazilian authorities could focus their attention on those babies most likely to have been affected by the virus.

The message is very clear. If you observe healthy women around the world, their babies grow in a similar way inside the womb, and achieve a similar size at birth, irrespective of where they are living, their ethnicity or their race.Professor Stephen Kennedy

A donation of $2.8 million from the Family Larsson-Rosenquist Foundation, a Swiss-based foundation that focuses on promoting and supporting breastfeeding and the use of human milk with the aim of granting every child an optimal start in life, is now helping the INTERGROWTH-21st Consortium to implement the international Preterm Postnatal Growth Standards. These standards describe optimal postnatal growth for babies born prematurely, provided they are breast fed.

Global adoption of the INTERGROWTH-21st Preterm Postnatal Growth Standards and the evidence-based feeding protocol for preterm infants is vital for promoting the use of human milk in neonatal units and breastfeeding clinics around the world so as to improve the survival and health of preterm infants. Professor Villar comments: ‘Preterm babies that are predominantly breast fed grow well, which substantially increases their chances of normal brain and motor development.’

‘In some parts of the world, however, babies are getting fatter due to poor nutrition’, Professor Kennedy states. ‘Breast milk is the key to ensuring that infants develop healthily and maintain adequate (rather than excessive) growth, thereby ensuring that obesity early in life is avoided.’

As part of its work on nutrition, the INTERGROWTH-21st Consortium is evaluating newborn body composition, e.g. the amount of fat present in the body, in addition to body size so as to understand better the value of breastfeeding for healthy growth and development. Professors Villar and Kennedy hope that the work will facilitate a global project focused on tackling obesity from infancy.

In summary, the INTERGROWTH-21st Project is already improving health outcomes for millions of children around the world, and raising international awareness about the need to identify, from early pregnancy onwards, those babies that are at most risk of poor health.