There were an estimated 866,800 conceptions in England and Wales, compared with 841,800 in 2005 / AP

A record number of women of 40 and over are becoming pregnant, figures from the Office of National Statistics show.

Julie Bentley, chief executive officer at the Family Planning Association, said better education, career opportunities and different lifestyle choices were behind the figures. She added: "As long as women are aware that their fertility naturally declines after 35, and it will probably take a bit longer to get pregnant, late motherhood is a valid choice."

Sue Jacob, of the Royal College of Midwives, said the trend was generally positive. "The evidence is leaning towards greater risks for pregnancies in women at that age," she said. "But today's women are healthier, and there are advantages to having children later: you are more informed, more in control emotionally and psychologically, and most importantly, you've planned it."

The report showed the number of conceptions for women between 15 and 44 rose by nearly 3 per cent. For every 1,000 women in this group, the number of pregnancies rose from 76 to 78.

There was a slight fall in teenage pregnancies, with the under-18 rate falling from 41.4 to 40.7 conceptions per 1,000 girls aged 15 to 17. Gill Frances of the Teenage Pregnancy Independent Advisory Group said there was a firm downward trend and predicted bigger falls in future. Britain still has the highest teenage pregnancy rates in western Europe.

Overall there were an estimated 866,800 conceptions in England and Wales, compared with 841,800 in 2005. Nearly four fifths resulted in birth or births. Fifty-six per cent of conceptions were outside marriage. Women aged between 25 and 29 had the highest rate of conception, at 129 per 1,000.