Over a third of babies (34.4 percent) born in Australia in 2008 were to mothers who were not married, registering a whopping rise in such births from 8.3 percent in 1970.
"For many children it's been a good revolution, but it depends on the extent to which they are in safe and stable homes," said the director of the Australian Institute of Family Studies, Alan Hayes, after a study.
The big rise in ex-nuptial births was to cohabiting couples, he said. However, the proportion of babies born to single women on their own remained stable since the early 1990s, The Age reported.
"It's difficult to generalise about the effects on the children," Hayes said. "It depends on whether the cohabiting relationship is long-term and stable, whether it leads to marriage, or whether it is fragile and part of a series of relationships."
Rebecca Huntley, director of Ipsos Mackay Research, said for many members of the cohabiting young generation, the sign of commitment was the decision to have children and to buy a house together. But later, when they could afford it, the couple splashed out on a big, ostentatious wedding.
"They see the wedding as a party with 150 friends," she said. "For their parents' generation a wedding was the licence to buy a house and have the children."
The proportion of couples who have lived together before marrying reached 78 percent in 2008, compared with 23 percent in 1980.
The percentage of working parents has also increased, with 63 percent of mothers of dependent children in jobs (mostly part-time) compared with 43 percent in 1981.