Record numbers of youngsters in Scotland have been placed on child protection registers, according to new figures.

Social service professionals and opposition politicians said the 13% increase reflected a worrying rise in the number of unborn children, babies and toddlers whose lives were endangered by their parents' drug addiction and followed a series of major scandals.

At March 2007, 2593 children were on the national child protection register - up from 2288 the previous year.

The biggest rise was among unborn babies, up from 18 to 31, a 72% increase.

Growing numbers of youngsters were registered at risk of emotional abuse - up by 26% from 438 to 550.

The Scottish Government said that, while any rise was concerning, the increases were a sign of improved reporting procedures bringing help to more children.

Adam Ingram, Minister for Children and Early Years, said: "I believe child protection is everyone's business. Being on the child protection register reduces the risks a child faces by making sure that services work together to meet the child's needs.

"The increased referrals to the register tell us that more people understand this and are taking action to report their concerns, meaning that more children are in a position to get the help they need when they need it."

He added that the government was determined to continue improving services for children at risk.

That work is badly needed, according to frontline child protection workers.

Christina Burnett, head of support for children, young people and families at Edinburgh City Council's social services department, said: "The rise is partly due to improved reporting but I think we need to look at the underlying issues as well.

"In Edinburgh we are seeing an increasing number of children under five who are registered (as at-risk) because of their parents' drug misuse. It is very concerning.

"These children will need long-term fostering and adopting and we need more people to do that - and more resources."

Liz Smith MSP, Shadow Minister for Children, Schools and Skills, said putting the rise solely down to a better reporting system "doesn't wash. Until we get to grips with tackling addictions and until we give our social work departments the staff they need then more lives will continue to be blighted," she said.

Anne Houston, chief executive of Children 1st, said: "There needs to be ongoing support both financially in terms of resources and also in terms of improving services.

"In the instances of concerns about unborn children, there needs to be a solid assessment to see if it is safe for children to stay with their parents."

Child protection services have been heavily criticised in a series of damning reports. Eleven-week-old Caleb Ness was shaken to death by his brain-damaged father in Edinburgh in 2001 after social workers decided it was safe to send him home with his recovering drug addict mother.

In December 2005, two-year-old Derek Doran died in East Lothian after drinking methadone in his parents' home.