Scotland is seeking to force producers to add folic acid to flour to stem an increase in birth defects - leading to a UK-wide change.

Folic acid helps to protect babies against a range of congenital malformations, including neural tube defects such as spina bifida, and pregnant women are advised to take supplements before and after conception.

But 85 per cent of women either do not take adequate amounts or do not take it at all either before or after conceiving a child.

The UK Department of Health, which has the final say on fortification, has said it is still “considering the matter” despite its advisors calling for the move for the past 16 years.

It is believed any decision taken in Scotland would have an effect throughout the UK, as commercial bakers would simply add folic acid to flour produced across the country.

The Scottish Government said it would prefer a UK-wide approach, but could not afford to wait for London to act, due to the high level of unplanned pregnancies north of the Border.

Public Health Minister Maureen Watt said: "The Scottish government has been convinced of the case for mandatory fortification for some time. Folate levels are a concern across the UK, but particularly so in Scotland and Northern Ireland.

"We are disappointed that, despite repeated lobbying from a number of sources, there has been no progress at UK level on mandatory fortification of flour with folic acid.

"I have recently written again to the UK government to press for a decision on this important issue.

"I, along with my counterparts in Wales and Northern Ireland, will consider how we might progress this should a decision not be forthcoming from the UK government."

Charity Spina Bifida Hydrocephalus Scotland cautiously welcomed the Scottish Government’s call.

Chief executive Andy Wynd said: “It is important someone takes the lead on this. There is absolutely no doubt that folic acid fortification is the right way to go. All the evidence indicates that an increase in folic acid will reduce the incidents of neural tube defects, of which spina bifida is the most severe.

“That is particularly important in Scotland as we have a higher level than the rest of the UK and recent studies are suggesting the folate levels of women in Scotland are slightly lower than the rest of the UK and the only way to deal with that is to take supplements.

“Over 50 per cent of pregnancies in Scotland are unplanned. The folic acid supplementation route has to be taken 12 weeks prior to conception. So supplementation on its own is not going to resolve the issue. Whereas fortification would ensure at least the levels went up and that would certainly make a difference.”

The charity believes adding folic acid to flour could reduce the incidents of neural tube defects by up to 70 per cent.

Around 80 countries already fortify their flour with folic acid and there is confusion as to why the UK Government is delaying a decision, despite its own advisors recommending the move.

There are concerns the change could be considered an extension of the “nanny-state”, but proponents of the move point out white flour currently contains added vitamins and calcium.

Experts have also pointed out only white flour will have folic acid added, ensuring consumers continue to have the choice of non-supplemented flour.

Current advice states pregnant women should take folic acid supplements three months before conception and throughout the pregnancy.

Folic acid naturally occurs in a range of foods including dark green leafy vegetables, fruit, nuts and beans. Avocado, spinach, and asparagus are among the foods with the highest folate levels.