The Office for National Statistics (ONS) said the conception rate in England and Wales rose between 2005 and 2006 for all women aged 19 and over.
But the rate for women aged 40 and over increased fastest, by more than 6% from 11.5 per 1,000 women aged 40-44 in 2005, to 12.2 in 2006.
Julie Bentley, chief executive officer of the fpa, formerly known as the Family Planning Association, said: “Every woman has to make her own decision about the right time to have a baby.
“As long as women are aware that their fertility naturally declines over the age of 35, and that it will probably take a bit longer to get pregnant, late motherhood is a valid choice.
“These figures illustrate that the traditional approach of ‘get married young and have children’ isn’t the reality for many British women.
“Improved education and career opportunities, different lifestyle choices and expectations mean their lives may take a different path.”
There were an estimated 866,800 conceptions in England and Wales in 2006, compared with 841,800 in 2005.