One in five of all children born in a single year in England was referred to social services before they reached age five, research suggests.
A study of children born in 2009-10 suggests up to 150,000 pre-school children were reported over fears of abuse or neglect, most unnecessarily.
Only 25% of referrals were formally investigated while 10% led to protection plans, the study said.
The University of Central Lancashire report said staff were wasting time.
The researchers said while public and professional vigilance was welcome, the number of alerts received by social services meant staff were wasting their time on innocent families, and making it harder to find the children who are at risk.
It follows a series of high profile cases where serious child abuse was missed by social workers.
The researchers used data from Freedom of Information Act requests to 150 councils, with 114 responding.
They found half a million children were born in those areas and 115,735 were referred to social services by last year.
When that was extrapolated across England, it suggested more than 150,000 children born that year had been brought to the attention of child protection teams by the age of five.
The report said its findings show the full extent of children's involvement in children's social care before the age of five.
Social workers are under intense pressure to make sure they do not miss any child at risk, and end up checking up more of the warnings they receive than is necessary, the research suggests.
It said: "Whilst some children needed to be protected, there is little evidence to support this scale of statutory involvement or the growing focus on early, and increasingly investigative, interventions alongside increases in removal of children from families into long-term care, special guardianship and adoption."
Lead researcher Professor Andy Bilson said other data showed how much time referrals took up.
'Needle in haystack'
He told BBC Radio 4's Today Programme that the majority of these concerns probably were not ones that were founded.
One example of a referral that did not make it beyond an initial assessment included a call from a neighbour who said a father was yelling at his children and might be taking drugs.
"Many of these lead to nothing," he said.
"We have this mantra that says it's everybody's job to safeguard children but what we are doing doesn't actually safeguard children.
"Creating these huge numbers of referrals of concern is like creating a huge, extra big haystack in which we are trying to find the needle of the children who are really at risk."
He added: "If you are a parent and someone has logged a complaint about you, it doesn't matter if you aren't formally investigated, you will still feel that you are under threat."
A Department for Education spokesperson said: "Ensuring children are safe and well looked after is our top priority - where there are concerns about a child's safety or welfare, it is only right that the appropriate people are informed and where needed, action is taken.
"We have introduced a new Social Care Bill that will continue to reform the care system so that we increase the quality of our social workers and ensure children receive the highest quality care and support.
"We are also enabling councils to look at innovative ways in caring for vulnerable children, backed by £100m of government funding."