Babies born just a few weeks early have a slightly higher risk of health problems in infancy¹, research suggests.

研究显示，早产几周的婴儿在婴儿期有稍高的健康问题。

Doctors said their work challenged widely held views that babies born after 37 weeks had similar long-term outcomes to those born at full term.

The study in the British Medical Journal looked at 14,000 children, born 10 years ago, up to the age of five.

It looked at health outcomes including admissions to hospital and having illnesses such as asthma²（哮喘） .

Child wheezing³

Previous work has focused on babies born very prematurely⁴, before 32 weeks.

But this study suggests that the higher number of babies born later may also need extra attention.

It found that babies born before 39 weeks have a slightly higher risk of health problems up to the age of five. The earlier the baby arrived, the bigger the risk.

For example, 15% of babies born full term experienced asthma or wheezing as young children but the figure increased to 17% for those born just a few weeks early.

They were also slightly more likely to go into hospital.

About a fifth of babies - some 100,000 a year - are born early at 37-38 weeks.

The authors of the study were at pains to stress that parents should not worry about what was a modest chance of extra illness.

But the work should instead be used to question the level of healthcare support and monitoring given to these families, they added.