Teenagers living in the poorest areas of Britain are more likely to get pregnant, but much less likely to have an abortion, according to a report yesterday from the office for national statistics.

It found the London borough of Southwark had the highest teenage conception rate, with 85 pregnancies per 1,000 women aged 15-18. This was more than five times the figure in Chiltern, with the lowest rate of 15.4 per 1,000.

For the most part, poorer areas in coalfields, manufacturing centres and ports tended to have higher teenage pregnancy rates than more prosperous and rural authorities.

Young women who became pregnant in areas with a high level of under-18 conceptions were more likely to have the baby than an abortion. But in parts of the country where teenage pregnancies were uncommon, up to two thirds ended with an abortion.

Manchester had the highest teenage conception rate in the north west region and the lowest percentage of abortions in England. Between 1992 and 1997 the city had an under-18 conception rate of 74.2 per 1,000 and 25.7% of these pregnancies ended in abortion.

By contrast, East Dorset had the lowest rate of teenage conceptions in the south west region (18.9 per 1,000) and the highest proportion of teenage terminations in that region, with 66% having an abortion.

The figures suggested that girls were more likely to keep a baby if they lived in parts of the country where teenage pregnancies were regarded as more socially acceptable.

London was an exception to the national trend, with above average conception rates and a high percentage of abortions.

The study showed that, nationally, Wales had the highest under-18 conception rate and England had the highest percentage leading to abortion. Scotland had low rates of teenage pregnancies and abortion.

The UK has the highest rate of teenage pregnancies in western Europe, with 95,000 conceptions last year, resulting in 58,000 live births. The government's target is to halve these figures by 2010.

Other findings in the ONS report on population trends included a decline in the divorce rate in England and Wales to the lowest figure for 10 years. Last year's 144,600 divorces affected 12.9 married people per 1,000, compared to 13.1 in 1990.

The average age of people divorcing rose, from 40.2 for men and 37.7 for women in 1997, to 40.9 and 38.4 respectively last year. The ONS said this was attributable to people marrying at a later age.

More people are divorcing for at least the second time, with one in five people who split last year having been through divorce before, compared with only one in 10 in 1981.