Fertility rates higher among women in 40s than those under 20 for first time since 1947
Fertility rates among women in their 40s are higher than those in their 20s for the first time.
The number of women giving birth in their 40s has tripled since 1981, according to figures from the Office for National Statistics (ONS).
And there were 15.2 live births per 1,000 women aged 40 and over in 2015 compared to 14.5 for those aged under 20.
Elizabeth McLaren, from the ONS, said: "Over the last 40 years, the percentage of live births to women aged 35 and over has increased considerably.
"Women aged 40 and over now have a higher fertility rate than women aged under 20 - this was last recorded in the 1940s."
The report said in most developed countries women have been increasingly delaying childbirth to later in life.
"This may be due to a number of factors such as increased female participation in higher education and the labour force, the increasing importance of a career, the rising costs of childbearing, labour market uncertainty and housing factors," it said.
Women aged 30 to 34 have had the highest fertility of any age group since 2004, when it was 25 to 29.