Couples who get married before having children are more likely to stay together, new research suggests.
The study, conducted by Marriage Foundation, showed that 76 per cent of mothers who were married before giving birth stayed with the child's father, compared to 44 per cent of those who married later, and 31 per cent of those who never married.
The report also suggests that a mother's level of education does not play as large a factor as previously thought.
Marriage Foundation used data from the Understanding Society study, a regular survey of 40,000 British households, and analysed a sample of about 1,800 mothers with at least one child aged 14 or 15.
Among couples who are still together who have teenage children, 81 per cent were married before their child was born, and 12 per cent got married later.
Whereas, of the mothers who were living with their partner at the time of their first child's birth but never got married, only 31 per cent had remained with their partner by the time the child was sitting their GCSEs.
The analysis also showed that the mothers who were married before having their child were on average four years older and more likely to have a degree, but this did not materially affect the stability of their relationship.
Among women who married before their first child, 82 per cent of those with a degree stayed with their husbands, in comparison with the 74 per cent of those without a degree.
Research director at Marriage Foundation, Harry Benson, said: "It barely seems to matter if women are younger or older, degree educated or not; so long as they make a plan for their future and marry before starting a family, they have a really good chance of making that relationship last.
"It stands to reason that there's one system that works best. It's one that worked for years," Benson added. "While it is right that we have done away with the social shame of having children outside marriage, we should not lose confidence in the value of crystallising commitment before starting a family," he said.
Sir Paul Coleridge, who is a former high court judge in the family courts, set up Marriage Foundation in 2012 to help build stronger families.
The report cites the £47 billion annual cost to the taxpayer of the effects of family breakdown. The think tank is launching a manifesto, calling on the government to "overcome their trepidation in championing marriage as the best chance families have to stay together."
Coleridge said: "The next government has a real chance to reduce the marriage gap between the haves and the have-nots. There is a serious and growing cause of real social inequality.
"The myths and misperceptions, such as that cohabitation is as stable as marriage should be eradicated by clear public statements and education."
The foundation also wants to see the government introduce a cabinet minister for families and support a tax benefit system that supports marriage.
"Governments cannot legislate directly for stronger families but they can foster the right environment and so make a real difference," Coleridge said.
"They spend £46 billion a year on family breakdown, mostly due to the increased tax credits and benefits awarded to single parents, and even more on the increased rates of truancy, juvenile delinquency and crime among people from broken homes."