One in five women has not had a baby by the time she is 40 years of age, official figures reveal.

A report published by the Office for National Statistics also shows that those with families are having far fewer children.

The number of 40-year-old women without children is now twice as high as it was 20 years ago while the number of women with larger families has halved over the same period.

Individuals have more options in their lives than ever before

FPA spokeswoman

The figures highlight the growing trend among many women to put off having children to concentrate on their careers.

Growing trend

The statistics suggest this trend is set to continue in the years ahead.

According to this latest report, two out of three women born in the 1970s have yet to have children.

This compares to those born in the early 1960s, half of whom had families by the time they were 25.

The average birth rate is now just 1.64 children. This is the lowest level recorded since statistics were first collected in 1924.

Women are now older when they give birth. In 2001, the average age of new mothers was 29 years. This compares to an average age of 26 in 1972.

Women are also opting for smaller families. Among current 40-year-olds, just one in 10 has four or more children. Twenty years ago, that figure was one in five.

Outside marriage

The report also shows that more women are choosing to have children without getting married.

Two out of every five births are now outside marriage - up one third in 10 years. In 1977, just one in 10 babies was born outside marriage.

The figures suggest that the UK will have to look towards immigration if the overall population is to grow.

On the basis of this report, the population would fall as deaths outpace births.

A spokeswoman for the Family Planning Association said the figures reflected changes in British society.

Speaking to BBC News Online, she said: "Individuals have more options in their lives than ever before and the social trends are clear - women are choosing to have fewer children, have them later in life or remain child free - but we make those choices in a social and economic context."