For the first time it can be said that fetal growth and birth size is not predetermined by genetics, but by the health status of the mother. Fetal growth and birthlength are incredibly similar when babies are born to well-nourished, well-educated mothers—despite diverse ethnic and genetic backgrounds.
Today INTERGROWTH-21st, an international study led by researchers at Oxford University, published its first results paper of the project, which proves the previously held belief that size and growth of babies differ due to ethnicity and race is not true. This has tremendous implications on the importance of maternal health care and interventions.
“Currently we are not all equal at birth. But we can be,” said the lead author Professor Jose Villar of the Nuffield Department of Obstetrics & Gynaecology, University of Oxford. “We can create a similar start for all by making sure mothers are well educated and nourished, by treating infection and by providing adequate antenatal care. Don’t tell us nothing can be done. Don’t say that women in some parts of the world have small children because they are predestined to do so. It’s simply not true.”
In order to study fetal and infant growth around the world, researchers studied nearly 60,000 pregnancies in eight defined urban areas in Brazil, China, India, Italy, Kenya, Oman, the UK and the USA. Using identical methodologies and equipment, researchers performed ultrasounds from early pregnancy through delivery to measure fetal bone growth and at delivery measured birth length and head circumference. This representative data is the first of its kind.
But why is it so important to have these standards and understand what affects fetal and infant growth? Currently no single global standard for fetal growth exists, instead there are at least 100 differing standards, posing problems for both identifying and treating undernourished newborns. “This is very confusing for doctors and mothers and makes no biological sense. How can a fetus or a newborn be judged small in one clinic or hospital and treated accordingly, only for the mother to go to another city or country, and be told that her baby is growing normally,” said Professor Stephen Kennedy, University of Oxford, one of the senior authors of the paper. The standard produced by the INTERGROWTH-21st fixes this problem. The standard serves as a global standard for fetal and infant growth—the first of its kind—and is consistent with existing WHO standards for infants. For example, the mean length at birth of the newborns in the INTERGROWTH-21st study was 49.4 ± 1.9 cm, compared with 49.5 ±1.9 cm in the WHO infant study.
The INTERGROWTH-21st growth standard will help maternal and neonatal practitioners around the world address the problem of poor growth. As of 2010, 27% of births around the world, or 32.4 million babies a year in low- and middle-income countries, are born already undernourished. Poor growth evident by small for gestational age babies has a significant implication on an infant’s start to life—putting them at increased risk of illness and death compared to babies well-nourished at birth. Small birth size also increases a person’s risk of diabetes, high blood pressure, and cardiovascular disease in adulthood. In addition, caring for undernourished newborns puts incredible strain and economic burdens on health systems and societies.
Until now it was thought disparities in growth were largely determined by unchangeable factors, like genetics. Now we know the ability to close disparities and ensure fetal and infant growth and health is in our hands. Professor Zulfiqar Bhutta, from The Aga Khan University, Karachi, Pakistan and the Hospital for Sick Children, Toronto, Canada, who is the Chair of the Steering Committee of this global research team, says: “The fact that when mothers are in good health, babies grow in the womb in very similar ways the world over is a tremendously positive message of hope for all women and their families. But there is a challenge as well. There are implications in terms of the way we think about public health: This is about the health and life chances of future citizens everywhere on the planet. All those who are responsible for health care will have to think about providing the best possible maternal and child health.”
Poor growth is not inevitable. Knowing that all babies can grow at the same rate empowers us to provide appropriate care—evidence-based care that ensures healthy mothers, healthy babies.
To read the full article on these new standards, click here. In addition, more information about the INTERGROWTH-21st Project, including updates on the release of the new growth standards, can be found at its website: www.intergrowth21.org