Vulnerable children are being damaged by long delays in family courts to decide if it is safe for them to stay with their parents, a charity says.
Barnardo's claims some children in Wales are waiting up to 59 weeks in unstable family homes or emergency foster care before a court rules if they will be taken into care.
The charity says it wants cases to be "fast tracked" through the courts.
A Ministry of Justice said a review into the issue is under way.
Court data from HM Courts Service (HMCS) shows that at the end of 2009 there were 836 care cases still waiting to be dealt with in Welsh courts.
That is 71% more than at the end of 2008, when there were 488 unresolved care proceedings cases, the charity said.
It added that new applications accounted for less than half of this increase, indicating that the courts are taking longer to close a "significant number" of cases.
In doing so the courts were increasing the risk that the children would be damaged long-term, Barnardo's said, with research suggesting they would have problems adjusting to jobs, relationships and money management in the future.
Yvonne Rodgers, director Barnardo's Cymru, said the problems had been caused by "insecurity" in the family courts, with additional expert assessments being routinely ordered.
"This paired with the evident lack of credence given to social workers, is causing unnecessary delay," she said.
"The courts need to reflect urgently on the damage these delays are having on extremely vulnerable children."
The data published by Barnardo's also uncovers a "postcode lottery"' governing the fate of children waiting for court decisions throughout Wales.
Barnardo's Cymru assistant director David Beard said the charity had established that in mid and west Wales, county court cases, which can be the most complex, were taking some 47 weeks, while in south east Wales they were taking 59 weeks.
He said: "That's somewhere around a year in the life of a child."
The charity is calling for a "radical culture shift in court practice" and wants the government to consider its recommendations, including:
- Ensuring all cases are dealt with in less than 30 weeks (seven months) with a tiered, fast track target of 12 weeks for children under 18 months
- Training for all court staff to improve understanding of the impact of delay on child development
- Improving links between legal staff and social workers to ensure there is greater confidence in social workers' professional expertise
Cardiff South and Penarth MP Alun Michael chaired the Cardiff juvenile court, a forerunner to the modern youth court, before he entered parliament.
He said the care proceedings system was "not geared to being timely and quick in the way it deals with things".
He said the degree of uncertainty was bad for the children and families, while the delays with the courts was "extremely worrying".
Mr Michael said he had come across examples of a failure to listen to the children because some professionals, including social workers and police officers, did not have the training and experience to handle difficult cases.
He said: "There is a need for certainty and that means we need to gear the whole system as we did when we tackled delays in the youth justice system, to ensure that decisions are taken much, much more quickly."
The Ministry of Justice said it is working to improve the situation in both England and Wales.
"A Family Justice Review is currently under way gathering evidence on problems in the current system and proposals for change," a spokeswoman said.
"The panel leading the review shares Barnardo's' concerns and has met their representatives to discuss suggestions for reform.
"Four thousand extra sitting days were added to the family courts earlier in 2010 to deal with care cases and the government will continue to monitor the situation."