Health

27 Apr 09

An international study on the growth of babies will particularly benefit the developing world

A large-scale international study will establish a new set of standards that describe the optimal, healthy growth of newborn babies and foetuses in the womb, thanks to a £8.7m grant to Oxford University from the Bill & Melinda Gates Foundation.

‘Millions of pregnancies and newborns the world over will be able to be assessed using the same standardised growth charts for the first time. This will improve the detection of babies that need special attention and so potentially save lives,’ says Dr José Villar, one of the principal investigators at Oxford University. ‘All countries will also have the means to identify, and concentrate resources on, the babies that need the most care.’

The study will particularly benefit the developing world, where undernutrition at birth is a major health problem. Worldwide, four million babies die each year soon after birth, and 98% of the deaths are in the developing world. Low birth weight is also connected to many future health and development problems. As a result, assessing the growth and nutrition of developing foetuses and newborns is a public health priority.

The INTERGROWTH-21st study will also form the largest multi-ethnic study to date on risk factors associated with premature birth and their postnatal growth. Up to 12% of babies are born prematurely, and it is a major healthcare problem. Preterm delivery is becoming more common in both the developed and developing worlds.

Foetal growth is usually assessed by measuring the height of the mother’s womb during pregnancy or by ultrasound measurements of the growing foetus. These measurements are then compared with growth charts to tell how well the foetus is developing. Newborns are also evaluated at and after birth in terms of weight, head circumference and length.

A large number of different growth charts have been produced in various hospitals and centres around the world. Each reflects the local population that was used to construct the growth chart and typically includes mothers of differing health and nutritional status. 

‘No one has developed international standards that outline the growth expected for healthy babies born to healthy mothers, and few existing growth standards, constructed under these conditions, relate the growth of a foetus or newborn to morbidity or mortality,’ says Dr Villar.

Oxford University clinicians and scientists based in the Oxford Maternal & Perinatal Health Institute at Green Templeton College, in collaboration with the Department of Nutrition for Health and Development of the World Health Organization and a network of institutions worldwide, will use the grant from the Bill & Melinda Gates Foundation to change this situation. They have set up a large-scale international study to determine new standards that describe normal foetal and newborn growth for healthy mothers anywhere in the world.

‘This has never been attempted on a global scale before,’ explains Dr Stephen Kennedy of the Nuffield Department of Obstetrics & Gynaecology at Oxford University. ‘The international community has been asking for such comprehensive charts for some time.’

Around 5,000 pregnancies will be monitored from 13 weeks to birth using both traditional measurements and basic ultrasound at nine different centres around the world. The study team will select populations that should show the best growth patterns in pregnancy and among newborns. For example, they will avoid mothers suffering from illness or malnutrition, or mothers who smoke.

‘If a mothers are in good health, and not living in a disadvantaged socio-economic environment, then regardless of their ethnicity or where they live, their babies should all grow well,’ says Dr Kennedy. ‘With our study, we will get a true international measure of healthy foetal and newborn growth for the first time. It will significantly improve our ability to detect babies that are undernourished or need extra care.’

The team will also look at babies within this group that are born prematurely to understand their postnatal growth in comparison with pregnancies that progress to term.

Finally, the team will evaluate morbidity and mortality rates among all newborns at the study centres specially concentrating on those that are preterm or malnourished at birth. This is expected to number about 50,000 babies.

‘This will give us a very powerful and complete measure of how nutritional status from conception to infancy affects their future health,’ says Dr Kennedy.