Worrying numbers of babies are being born with a congenital disease that means their intestines and other organs protrude through an opening near their umbilical cords.

The incidence has tripled in a decade among babies born to young mothers, the chief medical officer, Sir Liam Donaldson, revealed yesterday.

Babies with the condition are often born prematurely and may have growth problems. They nearly always need immediate surgery followed by a prolonged stay in a neonatal unit.

Sir Liam said gastroschisis "is a distressing condition for parents, but the outlook for the baby, following treatment is usually very good with over 90% of cases surviving with few long-term problems". Most cases were diagnosed before birth, allowing time for counselling of parents, careful monitoring during pregnancy and planning for treatment after birth.

Nevertheless it was vital to identify and better understand the causes of all such congenital illness. "The cause of gastroschisis is unknown but the main theory is that it results from disruption to blood supply during pregnancy."

Among risk factors that had been suggested were mothers' use of aspirin or recreational drugs, smoking, poor diet and social disadvantage.

Sir Liam called for urgent research into the condition and funding to improve national monitoring of the disease for which present records are patchy. There are no local registers covering much of eastern and northern England, Scotland and Northern Ireland.

One estimate suggests that prevalence rose from 2.5 to 4.4 per 10,000 births in Britain over the last decade with by far the biggest increases among mothers under 20. Four in 10 babies with the condition are born to mothers of this age.

Over the past 10 years, for mothers over 30, only one baby per 10,000 births has had the condition, compared with 5.5 for mothers aged 20 to 24 and 18 such cases for teenage mothers. There also seems to be a north-south divide with southern England having fewer cases than northern England, Wales and Glasgow.

Sir Liam said the under-reporting of all congenital anomalies was of major public concern. They accounted for about 15% of stillbirths and around a third of all infant deaths in England as well as contributing to childhood illnesses.

"Structural anomalies such as heart defects often require complex and highly skilled surgery, while chromosomal anomalies, such as Down's syndrome, tend to result in enduring disabilities that need skilled rehabilitation as well as long-term care and support."