Women in their mid-40s today are almost twice as likely to be childless as their parents' generation, new figures show.

The statistics look at how many children women have had by the age of 46 - when their childbearing days are considered over.

And they reveal one in five women who were born in 1969 are childless today - compared to one in nine women born in 1942.

Graph shows the number of women who remain childless by the age of 46 (blue line) has increased to 18 per cent for those born in 1969, compared to the previous generation of 11 per cent in 1942. The pink line shows how the number of 30-year-olds without children has steadily increased in recent years

Meanwhile two children remains the most common family size for middle-aged women today and the previous generation, according to figures released by the Office for National Statistics.

However whereas one in 10 women born in 1969 had four or more children, compared with around one in six women born in 1942.

There are no signs this trend is likely to reverse, with those who turned 30 last year typically having slightly fewer children than their parents and grandparents.

The decline of marriage, a rise in career-minded women and greater social acceptance for child-free mothers are some of the possible reasons less than half of today's 30-year-old's have become others to date.

The average family size has also decreased to less than two children while the previous generation usually had around 2.3 per household.

Just last week a report warned thousands of women are delaying having children for fear of not being the perfect mother.

Graphs shows the average number of children people are having by the time they finish childbearing (orange line) and aged 30 (purple line) by the year they were born (bottom axis)

Almost three-quarters of those surveyed by the British Pregnancy Advisory Service said the pressure of juggling a career and family life was putting them off trying to conceive.

Some worried about being labelled as a ‘part-time’ mother if they worked, or said they feared it would be ‘impossible’ to meet the expectations of their in-laws, friends and colleagues.

The report by the also found that one of the main reasons for women putting off starting a family was the struggle to find Mr Right.

Other concerns included not feeling ready for the responsibility a child, not owning their own home or simply not having enough money.

Official figures show that more than 40 per cent of births each year in England now are to women aged 30 and above.

This has led senior midwives to warn that older mothers who were more prone to complex births were placing a huge strain on maternity wards.

New Office for National Statistics figures show less than half of women have had a baby by 30 (file photo)

The BPAS report was based on a survey of 1,005 women aged 20 to 40, who hoped to have children.

A total of 71.3 per cent agreed with the statement that they were put off conceiving for fear of not being the ‘perfect mother’, This included 26.3 per cent who admitted they ‘strongly agreed’ with the statement.

The level of childlessness among women born in 1969 (18%) is higher than for women born in 1942 (11%). One in 10 women born in 1969 had 4 or more children, compared with around 1 in 6 women born in 1942. Office for National Statistics

The BPAS, which runs abortion and sexual health clinics, did not specify what was meant by the perfect mother but most women took it to mean being able to have it all and successfully juggle a career and family life.

One said: ‘I think women are expected to choose motherhood or career and that a woman attempting to do both is seen as a part-time mother and criticised by others.’

The survey also found that 46 per cent of women were delaying motherhood because they were not with the right partner.

A total of 50 per cent said they couldn’t afford a baby and 49 per cent admitted not being ready for the responsibility.

Clare Murphy, of the BPAS, said: ‘People take the decision to have a child extremely seriously indeed, and for the majority of women, finding the right person to do that with and ensuring that a child is being brought into a situation of financial stability is what matters most.

‘Rather than continually warning women about the risks of older motherhood, it would be more productive to push for policy measures that enable women to better combine paid work and motherhood, as many clearly want to do, while ensuring the healthcare services are in place to support the needs of those who wish to or need to wait.’