The first international standards for fetal growth and newborn size have been developed by a global team led by scientists from Oxford University, depicting the desirable pattern of healthy growth for all babies everywhere, regardless of their ethnicity or country of birth.
The standards have been developed as part of an international project that included participation of pregnant women in India.
They provide 3rd, 10th, 50th, 90th and 97th centile curves for the growth of a baby during pregnancy (as measured by ultrasound) and for a baby's size at birth according to gestational age (weight, length and head circumference).
Now, for the first time, all 120 million babies born each year across the world can be assessed using a common set of standards, reflecting how babies should grow when mothers have adequate health, nutrition, medical care and socio-economic status.
This means it will be possible to detect underweight and overweight babies early in life no matter where in the world they are born, a university release said.
"Being able to identify millions of additional undernourished babies at birth provides an opportunity for them to receive nutritional support and targeted treatment, without which close to 5% are likely to die in their first year or develop severe, long-term health problems," says senior author Professor Jose Villar of Oxford University.
The international standards - one for the growing fetus and the other for newborns - are published in two papers in the medical journal The Lancet. They were developed as part of the landmark INTERGROWTH-21st Project, funded by the Bill & Melinda Gates Foundation, which took over 300 clinicians and researchers from 27 institutions across the world six years to complete.
Poor growth in the womb resulting in small size at birth is associated with illness and death in infancy and childhood. It also impacts on adult health with increased risks of diabetes, high blood pressure and cardiovascular disease. Smaller babies result in substantial costs for health services and they are a significant economic burden on society as a whole.
Being born overweight is also a worsening problem, particularly in developed and emerging countries, as a result of rising maternal obesity rates due to overnutrition. Overweight babies are at increased risk of diabetes and high blood pressure later in life.
At present, over 100 different, locally produced, growth charts are used around the world to assess fetal growth and newborn size. These only describe how babies grew in a particular population or region at a given time. International standards, on the other hand, describe what can be achieved with optimally healthy growth.
The researchers calculate that, each year, at least 13 million more newborns worldwide will be identified as being undernourished using their international standards. These babies are now considered 'normal', when local charts adapted for undernourished populations are used.
The INTERGROWTH-21st Project involved almost 60,000 pregnant women in eight well-defined urban areas in Brazil, China, India, Italy, Kenya, Oman, the UK and USA. From this very large number, over 4,600 healthy, well-nourished women with problem-free pregnancies were enrolled to construct the standards.