This is from Brook Advisory, sex/relationship education from very young age is not mentioned as a factor and in my opinion is something that can help...
Reasons for high rates in the UK
The Social Exclusion Unit report Teenage Pregnancy identified three major factors for the UK's failure to reduce its teenage conception rates alongside those of other European countries.
Low Expectations. Teenage pregnancy is more common among young people who have been disadvantaged and have poor expectations of education or the job market. The UK has more young people who see no prospect of a job and foresee a future on benefits. As the report said 'put simply, they see no reason not to get pregnant.'
Ignorance. Young people in the UK lack accurate knowledge about contraception and sexually transmitted infections, they are uncertain of what to expect from a relationship and have an unrealistic picture of parenthood. Contraceptive use is low compared to countries like Denmark and the Netherlands and young people tend to have a rosy view of what being a parent is about.
Mixed messages. Young people are surrounded by sexual images and messages which imply that sexual activity is the norm. Yet some parents and many public institutions are at best embarrassed about dealing with young people's sexuality or try to ignore it completely. This leads to the situation, described by one teenager quoted by the Teenage Pregnancy Report, where it seems as if sex is compulsory but contraception is illegal.