Anxieties over staff attitudes and embarrassment at discussing personal issues were also concerns of young people about visiting sex advice services,

The study, commissioned by Brook Advisory Centres, said limited opening times and lack of publicity were also found to be bothersome.

Teenagers' fears about visiting centres could be leading to unprotected sex, a spokesperson for Brook warned.

Confidentiality

The law allows under 16-year-olds to receive treatment or advice in confidence.

However, the study confirmed previous research showing 25-50% of teenagers mistrust the confidentiality of their GPs and sex advice centres, the organisation said.

"For many young people, the fear that their parents will be told far outweighs any concerns about the results of unprotected sex and acts as a powerful deterrent to seeking early advice."

Young people expressed fears of being belittled, appearing stupid, or being made to feel "like a slag".

Young gays and lesbians seeking sex advice did not feel their needs were fully understood or catered for.

Younger teenagers were embarrassed both about being seen entering a sex advice centre and discussing personal issues with staff. Dealing with the receptionist was seen as a major hurdle.

Barriers

Alison Hadley is national policy officer for Brook Advisory Centres, which offer free, confidential advice on sex and contraception to young people.

She said: "As adults we often forget how difficult it is for young people to ask for sex advice and contraception.

"This research is a powerful reminder of the anxieties and apprehensions that all too often deter teenagers from visiting services.

"International research confirms that easy access to confidential contraceptive services is crucial in reducing teenage pregnancy rates, but for services to be used they must be trusted by young people.