Folic Acid and Neural Tube Defects

What is the story in Europe?

Neural Tube Defects (NTD) (anencephaly, spina bifida and encephalocoele) affect approximately one in a thousand pregnancies in Europe (equating to over 5,000 pregnancies annually). Anencephaly is always lethal. Spina bifida and encephalocoele cause serious disability in survivors. Over 70% of NTD affected pregnancies are prenatally diagnosed and terminated in most European countries, which represents a major tragedy for the parents.

In 1991 the Medical Research Council (MRC) Vitamin Study results confirmed that the majority of NTDs could be prevented if the mother took folic acid supplements prior to conception and in the first trimester of pregnancy¹. Folic Acid is a synthetic form of folate, which is a water soluble B vitamin most commonly found in green vegetables. Women are advised to take 0.4 milligrams of folic acid daily prior to conception and for the first three months of pregnancy.

However, most women do not take supplements prior to conception. This has led many countries worldwide to introduce mandatory fortification of flour with folic acid (to see a global and country specific overview of fortification, access the Food Fortification Initiative website). Three of the first countries to introduce mandatory fortification were the USA and Canada in 1998 and Chile in 2000. Studies following fortification showed reductions in the NTD rates in those countries ^2-5.

While voluntary fortification of some foods is available in much of Europe and the majority of European countries have policies to encourage periconceptional folic acid supplementation, European countries have been reluctant to introduce mandatory fortification. Reluctance has centered on fears that there would be adverse effects. The fears have mainly concerned the possibility of an association between folic acid and colorectal cancer, and the possibility of higher blood folate levels masking Vitamin B₁₂ deficiency in the elderly. In the UK in 2017, the Scientific Advisory Committee on Nutrition, having considered the available evidence on adverse effects, supported a recommendation for mandatory fortification ⁶. Following a public consultation, the UK government announced in 2021 that non-wholemeal wheat flour would be fortified with folic acid.

What does EUROCAT monitor about NTDs and Why?

Birth defects registries are vital to monitor the impact of strategies to raise the folic acid status of women periconceptionally in order to prevent NTDs.
Total prevalence of NTDs includes live births, stillbirths and fetal deaths from 20 weeks gestation with an NTD, and terminations after a prenatal diagnosis of an NTD. The total prevalence measure is used to track progress in primary prevention.
The live birth prevalence is used to inform EU Member States regarding the need to provide high quality health and other services for children living with an NTD and their families.
Birth defect registries are essential to monitor the prevalence of terminations of pregnancies with an NTD, as routine health care databases in Europe do not accurately record this information and over 70% of NTD diagnoses result in a termination ⁷.

What does EUROCAT data on NTDs tell us?

Countries vary in total prevalence (see EUROCAT Prevalence Tables)
Low total prevalence rates of NTD may indicate:
- better folic acid acid/vitamin status through supplementation and/or voluntary food fortification and diet;
- a lesser genetic predisposition for NTD;
- less exposure to other environmental risk factors;
- incomplete data.
There has been no real progress in preventing NTDs in Europe since folic acid supplementation was shown to be an effective preventive measure. NTD prevalence has remained relatively stable ^8,9.
The existence of EUROCAT registries in the UK for over 20 years will enable accurate monitoring of any changes in the prevalence of NTDs following the introduction of mandatory folic acid fortification.
Total prevalence of NTD (per 1,000 births) is one of EUROCAT’s six Key Public Health Indicators ¹⁰. Because many countries have focused their primary preventive efforts on prevention of NTD by folic acid supplementation, this indicator allows the success of these preventive programs to be measured.

“The potential for preventing NTDs by periconceptional folic acid supplementation is still far from being fulfilled in Europe. In order to achieve a reduction in NTD prevalence, new efforts are needed in all countries to implement a combined strategy to increase folate status by dietary means, increase uptake of folic acid supplements periconceptionally, and to increase availability and identification of fortified foods.”

“Member States should ensure that their registries are adequately resourced and supported to produce high quality data.”