It would be interesting to know how much of this is because the same factors which trigger care proceedings are also likely to harm the mother, and how much is because the care proceedings cause the harm. Either way, it's a big number and clearly more support needs to be available.
I think we also have to remember that the care proceedings are there to protect the child, and in theory are already a last resort after support has failed. Though I'm sure there's work to be done to improve that in practice.