How birth weight and growth in the womb affects future health will be the primary focus of the Born in Bradford research.

The project is the world's biggest research study into children's health and it will follow the lives of more than 10,000 babies born in the city in 2007/08.

Businesses, community groups and individuals are being urged to get behind the project and help raise £1 million towards the £3 million study.

Both birth weight and growth in the womb are recognised globally as an indicator of future health and the legacy of a low birth weight can extend into adulthood.

A low birth weight - less than 2,500g (about five-and-a-half pounds) - either the result of a premature birth or poor growth in the womb is strongly associated with increased infant mortality and an increased risk of developing various diseases in later life including heart disease and type two diabetes.

The causes of a low birth weight are poorly understood but they include lifestyle, culture and diet, social and environmental factors and the health of the mother.

South Asian babies are generally lighter than white babies and they also have a higher infant death rate. Evidence submitted by the Born in Bradford team to support their project shows that in the city - where around 45 per cent of the 5,500 plus births a year are to women of South Asian origin - the infant mortality rate is 9.9 per 1,000 live births. This is one of the highest in the UK - although it is comparable to rates in other districts with similar levels of deprivation. The national average is 5.3 per 1,000 live births.

Figures also show that infant and childhood disability is significantly higher in Bradford than the rest of the UK - particularly in children of South Asian origin.

For example more than 50 children in Bradford have neurodegenerative conditions - those which affect the function of the brain - with a total of 800 in the whole of the UK.

Nearly 140 autosomal recessive genetic disorders have been identified in children in Bradford, far higher than any other health district.

These disorders - which include cystic fibrosis and sickle cell anaemia - occur when the affected child has two copies of an altered gene, inherited from both parents.

Research shows low birth weight persists in South Asian babies even when their mothers are born in the UK, suggesting that the potential social and environmental advantages of living in Britain have little effect over one generation.

What remains unanswered is whether a lack of increase in birth weights in South Asian communities reflects genetic differences or lifestyle differences.

The Born in Bradford researchers believe that understanding more about birth weight is vital to child health and development and to efforts to tackle the burden of chronic disease in later life.

Derek Tuffnell, consultant obstetrician at Bradford Teaching Hospitals, said initial objectives would be to describe the differences in fetal growth and birth weight between ethnic groups, to investigate the causes of low birth weight in babies of South Asian origin and to study dietary and chemical exposure during pregnancy and investigate the link to growth and development.

Secondary objectives of the study will include determining the incidence, causes and predictive factors for adverse birth outcomes and congenital abnormalities, to describe the differences in birth experience and to study infant growth and development.

He said: "The results of the study will make a major contribution to our understanding of the genetic and environmental contributions to infant and child health."