The fertility rate for women aged 40 increased by 3.4% and this rate has more than trebled since 1981.
Liz McLaren, head of vital statistics outputs at ONS, said: “The trend for women to have babies at older ages continued in 2015. 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.”
Women aged between 30 and 34 have had the highest fertility rate of any age group since 2004 and prior to this, women aged between 25 to 29 had the highest fertility.
In 2015, fertility rates decreased for women in all age groups under 25 and increased for all groups over 30. The fertility rate for women aged 25 to 29 remained unchanged.
As a result, it means the average age of mothers in the UK and Wales rose to 30.3 years in 2015 and there are a number of reasons for this rise according to the ONS.
The ONS attributed the rise to:
• Advances in fertility treatment.
• More women in higher education.
• Attitudes towards the importance of a career.
• Rising costs of child care.
The report by the ONS stated that there were 697,853 live births in England and Wales in 2015, an increase of 0.4% compared to 2014. This figure has fluctuated following the 4.3% decrease in live births between 2012 and 2013, which was the largest annual percentage decrease since 1975.
The report also found that the total fertility rate decreased to 1.82 children per women in 2015. This was a slight drop compared to the 2014 figures, which found that the total fertility rate was 1.83 children per women.