A 12-YEAR-OLD schoolgirl and her 13-year-old boyfriend are believed to have become Britain's youngest parents.

She became pregnant at the age of 11 and gave birth to a girl weighing 7lb 4oz on Sunday. Being 12 years and three months old makes her five months younger than the previous youngest mother, Tressa Middleton, who gave birth in Edinburgh in 2006, according to The Sun.

A source told the newspaper: "The baby's mum and dad have been in a relationship for more than a year, so this isn't a fleeting romance. They intend to stick together and bring their daughter up together.

"They're very into each other, totally in love. She's in Year 7, he's in Year 9 at a different school."

April Webster and Nathan Fishbourne, the previous youngest parents, were 14 when their son Jamie was born in Caerphilly, South Wales, in 2010.

The new mother was 10 when she met her boyfriend. The pair, from north London, cannot be named for legal reasons. The schoolgirl lives with her mother, who is 27, and is supportive of the couple.

Yesterday, the new mother went to a register office to register the birth with her own mother and another woman.

Her classmates were "shocked" when they heard she had had a baby as she did not look pregnant right up until last month when she was still going to school, the Sun was told.

Hilary Pannack, chief executive of teenage pregnancy charity Straight Talking, said: "I know girls who've been pregnant at 13 and have had the baby, and I've heard of 12-year-olds before.

"It costs £100,000 to the taxpayer to support the average teenage mother in the first five years - it is a reason but is not the primary reason to stop teenage pregnancy, which is that we are talking about young people's lives.

"We need to stop the cycle of teenage parents having children who are more likely to become teenage parents themselves."

On youngsters having sex at such an early age, she said: "In the same way that young people understand how to smoke a cigarette, they may not necessarily be concerned with the implications. They do not necessarily think they could get cancer, they think they are immortal and it will not happen to them.They just do not understand the implications of early parenthood and they do not understand the responsibilities.

"It is not the end of their lives but they will be dependent on their parents for a long time and the state in the future because they do not have the qualifications and they may not stay together."