DRUG misuse among pregnant women in the region is much higher than previously suspected, a study has revealed.

Researchers from the Northern and Yorkshire Public Health Observatory found that close to one per cent of all babies were born to drug-misusing mothers during 2001.

The figure of 365 babies out of a total of 48,321 live births is about ten times higher than the previous estimate.

More than a third of babies born to drug-misusing mothers had to be treated for drug withdrawal symptoms the moment they were delivered.

Hospitals in Middlesbrough, Gateshead and Newcastle have some of the highest rates of deliveries to drug- misusing women in the region.

Doctors believe that the true scale of the problem is probably much higher because the information was based on interviews rather than drug testing.

They say it is vital that drug misusers are rapidly identified by the health service so mothers and babies can get the best possible treatment.

Dr Michael Grandey, a former Middlesbrough GP who carried out the research, said: "Up to now, very little was known about how common the problem was among pregnant women in the region."

Professor John Wilkinson, director of the Stockton-based Observatory, said: "This is a very important study, highlighting the need for midwives and doctors concerned with pregnant women to be increasingly vigilant."

The research team has recommended that action is taken to improve the availability and standard of services to drug misusing mothers throughout the UK.

Better information systems and data collection in hospitals are also needed, the team added.

Dr Grandey said the study, involving 37 maternity units in the region, was the most comprehensive since 1993 but probably failed to reflect the true scale of the problem.

He said women are using "harder and more dangerous drugs", which increase the potential harm to the mother and child.

Fran Toller, maternity services manager at the James Cook University Hospital in Middlesbrough, where 3,200 babies are born every year, said that when she took up her post eight years ago there were hardly any drug misusers going through the unit.

"That has changed. The numbers we are seeing are creeping up," she said.

Mrs Toller said she was pleased that so many women were willing to admit they were using drugs as this helped health professionals to give the help they needed.

"Some women fear that their baby will be taken away from them if they are on drugs. Our priority is to get the best outcome.