Pregnancy rates among teenagers are at their lowest level for almost 30 years but have risen dramatically among women in their 30s and 40s. Data from the Office for National Statistics (ONS) reveals a 5.9 per cent decline in rates among under-18s between 2008 and 2009, to 38.3 per 1,000 teenagers aged 15 to 17.

Overall, there were 38,259 pregnancies in this age group in 2009 compared with 41,361 in 2008, a decline of 7.5 per cent. Among under 16s, there were 7,158 in 2009, compared with 7,586 in 2008, a 5.6 per cent drop. Some 60 per cent of these pregnancies led to an abortion.

The biggest increase in conception rates was among women aged 30 to 34 - a 3.5 per cent  leap between 2008 and 2009. And in 1990, 89.7 per 1,000 women in this age group fell pregnant, rising to 125.9 per 1,000 in 2009.

Overall, 213,300 women in this age group fell pregnant in 2009, up from 161,400 in 1990. The data for England and Wales showed a big jump among women aged 35 to 39, from 33.6 conceptions per 1,000 women in 1990 to 60.1 in 2009.

Some 116,500 women aged 35 to 39 fell pregnant in 2009, compared with 56,000 in 1990. Among women aged 40 and over, rates almost doubled from 6.6 per 1,000 in 1990 to 12.8 in 2009. In 1990, 12,000 women in this age group fell pregnant, more than doubling to 26,800 in 2009.