Over-40s now having more babies than under-20s
The fertility rate for women aged 40 and over has risen above that for the under-20s for the first time since 1947.
A new report from the Office for National Statistics (ONS) for England and Wales found 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.
In 1981 the rate was 4.9 for women aged 40 and over compared to 28.1 for women under 20.
This means the fertility rate among older women has more than trebled since 1981.
The report also said more than a quarter (27.5%) of births in 2015 were to mothers born outside the UK - the highest level on record. This percentage has increased every year since 1990, when it was 11.6%.
The long-term rise in babies being born outside marriage or civil partnership has also continued, the ONS said, with 47.7% of all babies in 2015 born outside marriage or a civil partnership, up slightly on the previous year.
On the trend of older mothers, the report said: "In most developed countries, women have been increasingly delaying childbearing to later in life, which has resulted in rising fertility rates among older women.
"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."
There were 697,852 live births in England and Wales in 2015, an increase of 0.4% from 2014.