The number of women giving birth in their 40s has trebled in the past 20 years, new statistics have revealed.
According to research by the Office of National Statistics (ONS), there has been a surge in couples putting off starting families because of financial reasons, or the greater availability of fertility treatment.
The figures show that in 2011, 29,350 women aged 40 or over had a baby, compared with just 9,835 in 1991.
Despite repeated warnings from doctors that fertility declines rapidly after the age of 35, the number of women aged 35 to 39 who gave birth last year increased by 3.4 per cent from 2010, proving that the trend is growing in popularity.
Experts claim that other factors, including a desire to make career progress and get on the housing ladder, have also persuaded many women to delay having children.
Justine Roberts, founder of parenting advice website Mumsnet, told the Metro: "There are lots of different reasons why parents are getting older - some want to live a bit before having their career wings clipped by motherhood, others are just saving up to be able to afford it."
Meanwhile, the findings claim that almost half of all babies are now born to unmarried parents.
The ONS says that last year alone, 47.2 percent of the 723,913 new babies in England and Wales were born to parents who were not married or in a civil partnership.
A spokesman for the ONS said: "The rise in 2011 represents a continuation of the increasing age of motherhood since 1975.
"These trends reflect the increasing numbers of women delaying childbearing to later ages. This may be due to a number of factors such as increased participation in higher education, the desire to establish a career, getting on the housing ladder and ensuring financial stability before starting a family."