Image copyright PA Image caption Experts suggest teen pregnancy rates are falling as girls choose to drink less alcohol and socialise online

The number of teenage girls getting pregnant in England and Wales is continuing to fall, figures show.

There were about 23 conceptions per 1,000 15 to 17-year-old girls in 2014, compared to a high of 55 in 1971, the Office of National Statistics said.

That means that a target, set in 1998 by the then Labour government, to halve teen pregnancies by 2010 has finally been met, six years late.

Alison Hadley, who led the government's strategy, warned the job was not over.

Ms Hadley, from the University of Bedfordshire, said it was "an extraordinary achievement", given that many thought the goal was unattainable and high rates were "an intractable part of English life".

Easy-to-use contraceptive

Education programmes and easier access to contraception played a part in bringing down rates, even in deprived areas. But she added: "Despite the big reduction, the job is not done.

"England continues to lag behind comparable western European countries, teenagers continues to be at greatest risk of unplanned pregnancy and outcomes for some young parents and their children remain disproportionately poor," she said.

She highlighted the differences between regions, with girls in the north east of England more likely to get pregnant than those living in the South East and South West.

"It is vital to keep a focus on teenage pregnancy to sustain the progress made and narrow inequalities," she said.

"Universal, high quality sex and relationships education, well-publicised, easy-to-use contraceptive and sexual health services, a youth-friendly workforce and good support for young parents, all need to be in place so successive generations of young people have the knowledge, skills and confidence to make choices.

"Disinvestment now risks an upturn in the rates," she added.

Areas with highest conception rates among under-18s in England and Wales Local authority 2014 2013 1998 1. Nuneaton and Bedworth 43 29.7 48.8 2. Stoke-on-Trent 42.4 43.9 68.5 3. Tamworth 42 44 55.7 4. North East Lincolnshire 40.8 43.3 69.8 5. Kingston-upon-Hull 39.3 35.9 84.6 6. Preston 38.6 35.7 49.7 7. Sandwell 38.3 36.6 69.1 8. Norwich 38.1 31.4 53.7 9. Walsall 37.5 36.8 67.2 10. Blackpool 37.3 41.7 64.8

Clare Murphy, from the British Pregnancy Advisory Service, said shifts in teenage behaviour may also be factors in the falling number of pregnancies, together with better access to contraception and sex education.

"The plummeting level of teenage drinking, for example, may be reducing the likelihood of unprotected sex, and teenagers are also increasingly socialising online, limiting the opportunities for sexual activity," she said.

The ONS research also found:

• The estimated number of conceptions to girls under 18 fell to 22,653 in 2014 compared with 24,306 in 2013, a decrease of 6.8%

• An estimated 4,160 girls under 16 got pregnant in 2014, compared with 4,648 in 2013, a fall of 10%

• There were some 871,038 conceptions to women of all ages in 2014, compared with 872,849 in 2013, a slight decrease of 0.2%

• Conception rates in 2014 increased for women aged 25 and over, and decreased for women under 25