The number of births to older mothers has almost trebled in 20 years and is continuing to rise, figures have shown.
Some 26,976 babies were born to women aged 40 and over in 2009, compared with 9,336 in 1989 and 14,252 in 1999, figures for England and Wales show.
Among those aged 35 to 39 there were 114,288 births in 2009, a rise of 41% on the 81,281 in 1999.
The data, published by the Office for National Statistics, showed a 0.3% drop in the overall number of births.
The data means the typical age for a first-time mother has risen to 29.4 in 2009, compared with 29.3 in 2008 and 28.4 in 1999.
Compared with 2008, the birth rate for women under 35 has fallen. There was a 2.3% drop among women under 20, from 26 births per 1,000 women in 2008 to 25.4 in 2009.
Rates for women aged 20 to 24 and 25 to 29 fell by 1.6% and 1.4% respectively, while for women aged 30 to 34 there was a 0.4% decline.
But rates for women aged 35 to 39 and 40 to 44 continued to rise in 2009, by 1.2% and 2.4% respectively.
Women had an average of 1.95 children each in 2009, down from 1.97 children the previous year.
The figures also showed that the proportion of births to mothers born outside the UK continued to rise, from 24.1% in 2008 to 24.7% in 2009.
The proportion of births to overseas mothers has increased every year since 1990, when it was just under 12%. In 1999, the figure was 14.3%.
Louise Silverton, deputy general secretary of the Royal College of Midwives, said the small decline in the birth rate was "a tiny morsel of good news".
"The birth rate has gone up by 19% since 2001 yet the number of midwives has risen by only 11% over the same period.
"The figures also mask the fact that an increasing number of births are becoming more complicated, requiring more of midwives' time.
"This very small decrease in the birth rate should not be used as an excuse to stop or reduce the promised rise in the number of midwives."