The UK has the highest teenage pregnancy rate in Europe
A multi-million pound project to reduce pregnancies among youngsters deemed at risk has been abandoned after research showed it was not cutting conceptions.
The £5.9m Young People's Development Programme (YPDP) offered support and advice to disadvantaged teenagers in 27 parts of England between 2004 and 2007.
But teenagers who took part were actually more likely to fall pregnant than those in comparable groups.
The research appears in the British Medical Journal.
The YPDP was modelled on a similar programme implemented in the US, and was one of a number of measures in recent years aimed at reducing Britain's doggedly high teenage pregnancy rate.
Figures released this year show the numbers of conceptions among the under-18s have increased, dealing a blow to government plans to halve rates by 2010.
Mixing and matching
A total of 2,371 teenagers deemed at risk of exclusion from school, drug abuse and teenage pregnancy took part in the YPDP over the three years it ran, at a cost of £2,500 each.
Of these, some 16% fell pregnant.
This compared with 6% in other groups of youths deemed vulnerable but which were not taking part in the YPDP. These included for instance teenagers from Pupil Referral Units, who were being educated for various reasons outside of mainstream school.
The YPDP group had sex earlier, and reported a higher expectation of becoming a teenage parent.
The young women in the group were more likely not to have used contraception when they most recently had sex.
However researchers acknowledged that it was difficult to match precisely YPDP groups with similar groups, and that this could account for the significant differences between the two.
"We tried very hard to adjust for differences but there may be factors that we didn't take into account," said Meg Wiggins, lead researcher from the Institute of Education at the University of London.
"But one of our theories is that YPDP pulled together vulnerable teenagers sometimes from across a wide area - being brought together in this way may have had an effect on their behaviour that you wouldn't see in groups more rooted in the local community.
"There is also the issue of time spent - YPDP involved a few hours a week in addition to other commitments, whereas some of the other groups were much more intense."
The research did suggest that these pupils were less likely to be playing truant from school at the end of the 18 month evaluation, and the young people themselves rated the programme highly.
A spokeswoman for the Department of Health said: "Overall, teenage pregnancy rates have been going down for the last 10 years.
"It's right that we continue to look for new ways of reaching out to young girls to prevent them from getting pregnant.
"This pilot was based on a successful American programme. It didn't appear to reduce teenage pregnancy so we will not be taking it any further."
Simon Blake, national director of sexual health services provider Brook, said it would be wrong "to dismiss all youth development programmes as ineffective as a result of these findings - achieving positive success in reducing teenage pregnancy amongst disadvantaged young people is an important and ongoing responsibility.
"We must take the learning from this programme to inform future, rigorously evaluated work in the UK."