Vulnerable children in the north of England are almost twice as likely to end up in care as their peers in the south, according to new research.
In London, just a quarter of applications resulted in a child going into a foster home or being placed for adoption.
But the figure compared to almost half (46 per cent) in the North West, which had the highest rate of care orders and the lowest for supervision orders (nine per cent).
But there was a reverse in the capital which had the most supervision orders (28 percent).
Scientists said the North-South divide in the way children are dealt with by local authorities and the Family Courts was a surprise.
Overall, vulnerable children facing being taken into care are 70 per cent more likely to end up in proceedings if they live in north-west or north-east England than those living in London or the south-east.
Study leader Professor Judith Harwin, of the University of Lancaster, said: "The finding of a north-south divide in the use of supervision orders and care orders was unexpected.
"Deciding on whether children should return home is one of the hardest decisions a court can make and risk appears to be weighed up differently in the north and south.
"Of course we need to explore the dynamics behind these statistics but it raises questions about the fairness of the system."
She added: "Our finding that children living in the north have significantly higher risk of ending up in care proceedings says to me children's vulnerabilities to risk are unequal, and children are bearing that risk.
"The north-east and north-west account for 27 per cent of all children, but also for more than a third (35 per cent) of all care proceedings. That forces the question: why?"
The study was presented at a conference at the university to explore care demand and enable professionals from all over the North to hear and debate the issues, highlighting regional differences.
North East children are at greater risk of being subject to Family Court proceedings than in any other area, with more than 4,000 care and supervision proceedings in 2015/16. This compared to fewer than 3,000 in the South West and London.
The likelihood of a child ending up in care proceedings also depends on where they live with incidence in the north-east 34 per 10,000, compared to outer London where it was about 13 per 10,000.
The findings come amidst what has been described as 'a looming crisis' in care demand, putting the courts and children's services under massive strain.
The research, funded by the Nuffield Foundation, analysed recurrent care proceedings, supervision orders and special guardianship with extended family or friends, and was prompted by a the President of the Family Division, Sir James Munby.
Local authority and court cultures have a marked effect on the likelihood of a child returning home to the family, under the supervision of the local authority responsible.
This is less likely to happen with children in the North and Midlands than in the South, meaning more of the latter return to court for fresh proceedings because reunification has broken down.
Special guardianship has increased nationally whilst placement orders, which sever family ties, have gone down.
The findings have important implications for policy and practice, according to the researchers.
They have called for the north to receive priority attention with more resource allocation and preventive family support strategies to help reduce the risk of children becoming the subject of care proceedings.
They also want a better understanding of regional patterns and trends to help inform local decision-making beyond, what they describe, as the current narrow range of indicators.
They say the crucial question is the issue of fairness which should be at the heart of any justice system.
Co author Prof Karen Broadhurst added: "Courts and local authorities need to be able to share and compare practices to increase consistency and fairness for all children and families. At present there are insufficient opportunities for regions to do this."
She added: "We have been concerned about the disproportionate removal of children from poor areas since the 1980s, so why aren't we doing anything about it - and why is resource allocation not more closely aligned to deprivation?"