Figures show that there was an increase in pregnancy rates among disadvantaged teenagers despite a £5.9 million initiative designed to cut numbers.
The government's Young People's Development Programme (YPDP) was introduced to 27 parts of England and ran between 2004 and 2007, but the results of the scheme, which was based on a similar model in New York, show that it failed to cut teenage pregnancy rates.
A report claims that young women who attended the programme, at a cost of £2,500 each, were "significantly" more likely to fall pregnant than those in a comparison group, despite support and education for those deemed at risk of exclusion from school, drug abuse and teenage pregnancy.
A total of 2,371 teenagers aged 13 to 15 took part in the programme, but figures show that 16% of the YPDP group fell pregnant compared with 6% in a youth group not receiving YPDP funds.
The study, published in the British Medical Journal, said: "Young women in the intervention group also more commonly reported early heterosexual experience (58% v 33%) and expectation of teenage parenthood (34% v 24%)."
Despite receiving education about sex and drugs, free condoms and being no more sexually active than the other group, the YPDP group were more likely to have not used contraception.