MOTHERS-TO-BE with lower levels of folic acid are more likely to have babies with lower, less healthy, birth weights, according to North-East scientists.

The health benefits of taking folic acid (vitamin B9) before and during pregnancy are already known, but this is the first time that folic acid levels in UK mothers have been linked with birth weight.

The NHS advises women to take folic acid at their first pregnancy check-up, but this means many women miss out in the crucial, early stages.

Dr Caroline Relton, from Newcastle University, said: "This evidence strengthens the argument for fortifying everyday foods like bread and cereals with folic acid."

Researchers who studied 1,000 women found higher levels of folic acid were linked with increased birth weights.

Expectant mothers who smoked were more likely to have lower levels of folic acid in their blood, which might explain why women who smoke often have smaller babies.

Seven per cent of all babies born are low birth weight (less than 2.4kg or 5.5lbs) and they have a 50 per cent chance of having a disabling condition.

Ruth Reckitt, from Hartlepool, who took folic acid supplements just before she became pregnant and during the first three months, gave birth to a boy, Jude, and a girl, Nell, six months ago. The twins each weighed more than 2.4 kilogrammes (5.5lb), which marks a healthy birth weight.

She said: "I knew folic acid was good for me and my babies, and I'd also had sisters who had taken folic acid during their pregnancies."