Women are being urged to take folic acid supplements before they become pregnant.

Women are being urged to take folic acid supplements three months before getting pregnant, after the Scottish Spina Bifida Association (SSBA) reported a substantial rise in the amount of cases.

The SSBA has seen 15 cases of babies born in the country with the condition this year – which is about twice the normal number.

Spina bifida is a fault in the spinal column in which one or more vertebrae (the bones which form the backbone) fail to form properly, leaving a gap or split, causing damage to the nervous system and often paralysis from the waist down.

Much research has shown that folic acid supplements help prevent the condition – it is believed that up to 75% of cases could be prevented by the mother taking folic acid three months before conception, and during pregnancy.

The charity is warning, however, that factors such as unplanned pregnancies can mean the vitamin is taken too late – hence is urging all women of child-bearing age to take extra folic acid.

SSBA Chairman and consultant geneticist Dr Margo Whiteford told the BBC: “Ladies do know about folic acid preventing spina bifida but they wait until they’ve missed a period before they start taking it.

“The spinal cord develops within the first four weeks of pregnancy so by that stage it’s too late - if the baby’s going to have spina bifida it will already have developed it.”

Scotland has the highest rate of children born with spina bifida in the UK because Scottish mothers are less likely to abort the foetus once the condition is diagnosed. Half of affected pregnancies are terminated in Scotland, compared with 90% in the rest of the UK.

In 2007 the Food Standards Agency (FSA) recommended that folic acid should be added to bread or flour. At this time, however, the recommendation is under review following new research which suggested it could increase the risk of colorectal cancer.

Folic acid, vitamin B9 or folate as it is known in its natural form, is present in leafy green vegetables, dried or fresh beans and peas, fortified breakfast cereals, sunflower seeds, liver products and baker’s yeast.