Greater weight gain after birth was a risk factor

Babies with low birth weights are known to be prone to lung problems.

But, for the first time, greater weight gain in the weeks following birth has been linked with impaired lung development.

The University of Southampton study appears in the American Journal of Respiratory and Critical Care Medicine.

Chest problems

The researchers measured the lung function of 131 healthy babies aged five to 14 weeks and looked at the speed these babies gained weight.

Some of the babies had a lower than normal birth weight.

The babies with a lower birth weight and a greater weight gain in the early weeks after birth had poorer lung function than the other babies.

Dr Jane Lucas of the University of Southampton's School of Medicine, who led the study, said it was unlikely different types of feeding could be responsible for this effect.

She said: "What it does seem to show is that the babies that grow fastest after birth actually have poor lung function and they are probably the ones showing catch-up growth.

It adds weight to the evidence that the building blocks for a healthy future may be determined in the womb. Dr Matt Hallsworth from Asthma UK

"It's not that they have grown quickly that is the problem, it's that they were compromised in the womb to some degree.

"That would mean that the unborn babies' lungs had not reached their normal dimension, which would contribute to reduced lung function," she said.

Co-researcher Professor John Warner said: "We believe the reduced lung function in these infants may have implications for susceptibility to later respiratory disease, in particular asthma."

They plan to follow the babies into later life to determine whether this is true.

A British Lung Foundation spokesperson said: "We have long been aware of the respiratory problems facing premature babies and young children.

"We are delighted to be involved in this project and believe more research is needed to explore the link between lung disease in babies and the likelihood of developing further lung problems in later life."

Dr Matt Hallsworth from Asthma UK said: "The results of this study point to early life as a key stage in the development of a child's lungs and how this influences the risk of conditions such as asthma.

"It adds weight to the evidence that the building blocks for a healthy future may be determined in the womb."