Women aged 25 are now more likely to have had a child than to be married. The latest landmark in the decline of marriage was uncovered yesterday in Social Trends, the annual snapshot of the nation by the Office for National Statistics.

Until recently more women had married by the age of 25 than had had a child.

In the 1970s nearly 80 per cent of women were married by 25, compared with 25 per cent now. About 50 per cent of 25-year-old females in the late 1970s had given birth. Although the figure has now fallen to 30 per cent, that is still more than the number getting married.

The ONS report also showed that the number of people getting married has dropped to its lowest level since 1895. Only 237,000 marriages took place in England and Wales in 2006 and the proportion of people who marry is now lower than when the rate was first calculated in 1862.

Both men and women are leaving marriage until later in life, with the average age of a man marrying for the first time rising from 29 ten years ago to 32 in 2006. For women, the average age of marriage has also increased from 27 to just under 30 — 29.7 — over the past ten years.

The biggest decrease in the numbers marrying was among those aged between 20 and 24, which has fallen from almost a fifth of all marriages to 11 per cent in ten years. The report also showed that many women are delaying starting a family until they are older. In 1971 the average age for a woman to have her first child was just under 24. In 2007 it was 27.5.

However, women who are not married are more likely to have a child younger: the average age for an unmarried woman in Britain to give birth was 27 in 2007, compared with 31.5 for married mothers.

The survey also noted a significant increase in the number of people living on their own, which has doubled since 1971. Nearly seven million people, 12 per cent of adults, live on their own, with the largest increase among adults of working age.

One quarter of households in Great Britain in 2008 consisted of couples who did not have children — a 6 per cent increase since 1971, when the figure was 19 per cent.

The survey also showed that the number of pensioners outnumbered the number of children under 16 for the first time in 2007. There has been a threefold increase in the number of people aged 90 and above since 1971, with the number now approaching 500,000.

The expected increase in the number of pensioners is also potentially worrying for healthcare providers and social services: the report showed that council spending on older people rose from £4.5 billion in 1997 to £8.66 billion in 2007, the largest expenditure on any one group.

The survey of key events in women’s lives before they turned 25 was carried out between 2001 and 2003, and asked women under 60 if they had been married or had a child by the time they were aged 25.

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