Health visitors can pick up problems in families with young children
There is a "clear North-South divide" and "huge variations" in the access English children and parents have to health visitors, campaigners have said.
The Family and Parenting Institute says County Durham Primary Care Trust's ratio of one health visitor for every 165 children is the country's best.
But it says in some London PCTs there is just one for every 800 children.
The union Unite, due to meet Department of Health officials next week, says the "crisis" must be addressed.
Lord Laming, who carried out inquiries into the Victoria Climbie and Baby P cases, has already published recommendations saying the number of health visitors needs to be increased.
The Family and Parenting Institute (FPI) has been campaigning for more health visitors since 2007.
It is calling for three changes to improve the way the service is organised.
- A universal health visitor service with an intensive service for parents who will benefit most
- A preventative health visitor service to help support the most vulnerable families
- Better training and career structures for health visitors
But it warns there is a "clear North-South divide" in the health visiting service.
The top three performing PCTs, when it comes to health visitors, in England were County Durham, Darlington and Bournemouth.
Of the 10 PCTs with the lowest number of health visitors, eight of them were in London.
The Community Practitioners and Health Visitors Association (CPHVA), now part of Unite, which represents health visitors, recommends each should have a case load of no more than 250 children.
The FPI says only 15 of the 136 respondents meet that target.
Chief executive Mary MacLeod said: "The value of health visitors is unquestionable. Parents tell us they are a lifeline.
"Health visitors respond to parents' worries and concerns, and their unique relationship and position of visiting families in their home means that they can detect problems that parents may not talk about - such as post natal depression, domestic violence or child abuse.
"This postcode lottery is unacceptable. We need a universal health visitor service so that all parents can have the support they want and need and children's wellbeing can be safeguarded."
Karen Reay, Unite national officer for health said: "The FPI findings reinforce Unite/Community Practitioners' and Health Visitors' Association's long-standing demands that an extra 4,000 health visitors are employed and that training budgets for the next generation of health visitors are immediately restored.
"We look to the Department of Health 'summit' on health visiting on 5 May to formulate a practical programme of action over the next two years to address the crisis in the profession."
A Department of Health spokeswoman said: "We are aware of the need to encourage greater investment in health visitors, and in February 2009 introduced the Child Health Strategy, which emphasised the importance of health visitors in delivering healthcare to children.
"We are also ensuring that healthcare and children's services are better integrated so that children and families have stronger and better joined up support during the crucial early years of life.
"The government response to the Laming Report emphasised the importance of health visitors leading high quality children's services and we expect to see the numbers of health visitors rise significantly in future years."