A 15-year-old schoolgirl who only found she had HIV when she became pregnant has given birth at a hospital in Swansea, it has emerged.
The disease was detected during a routine ante-natal clinic check
The girl, who has not been named, had no idea she had the infection until she was screened at an ante-natal clinic.
Doctors were able to treat her and the baby has so far tested negative but needs another test in three months.
Campaigners said the case highlighted a growing HIV problem among heterosexuals in Wales, especially the young.
The new mother, thought to have had only two sexual partners, was infected by an older man who was also the baby's father.
Swansea's Singleton Hospital, in common with many throughout the UK, routinely offers the test to all pregnant women who give birth there.
HIV consultant Kathir Yoganathan, said the girl's case was "shocking".
He added: "If she hadn't become pregnant she would not have known that she was HIV positive. In young people it takes 10 to 15 years before symptoms appear.
"If we know that a woman is HIV positive before the baby is born there is a very high chance - 99% - that the child will be OK."
The girl was given anti-retroviral drugs, advised not to breast feed and the baby was delivered by caesarean section.
Of the young mother, Mr Yoganathan said: "She may not need treatment for some time yet.
"HIV is a terrible disease, one which needs life-long treatment, but people can live a normal life span.
The baby was born at Singleton Hospital in Swansea
"The sad thing is that there are still people who know they are at risk and refuse to accept it and get tested."
Lynda Bevan, of the Swansea based Aids Cymru Trust, said more needed to be done in Wales to highlight the risks of contracting HIV.
"I'm not surprised that 15-year-olds are in danger of contacting the virus because the communities at large in Wales are not aware of the dangers surrounding unprotected sex," she said.
"People think that someone else is going to get it and not them. Anyone and everyone can catch the HIV virus.
"It is no longer a gay issue. It's a heterosexual issue.
"This young girl has been fortunate really that it's been found out so soon."
Sexual health charity The Terrence Higgins Trust said infection rates for the virus, which can lead to Aids, has risen 45% in two years in Wales.
It released figures late last year showing there were 575 new cases in Wales in 2003 compared to 398 in 2001.
Dr Yoganathan said that last year he had seen 32 new HIV patients at his clinic in Swansea, but there had been 36 new cases so far this year.