What is the story in Europe?

Neural Tube Defects (NTD) (anencephaly, spina bifida and encephalocele) affect approximately one in a thousand pregnancies in Europe (equating to over 5,000 pregnancies annually). Anencephaly is always lethal. Spina bifida and encephalocele 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 Global Fortification Data Exchange). 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 countries2-5.

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. As of July 2023, Moldova was the only European country with mandatory folic acid fortification6. The UK plans to fortify non-wholemeal wheat flour with folic acid by the end of 2026.

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 termination8.

What does EUROCAT data on NTDs tell us?

  • Countries vary in total prevalence of NTD, from comparatively low prevalence in the south of Europe, to higher prevalence in the north of Europe. Folic acid fortification will have greatest value in countries with high prevalence of NTD.
  • 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 stable9,10.
  • 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 Indicators11. 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.
  • Had folic acid fortification been implemented in EU member states in 1998 (at the same time as the USA), an estimated 19,500 neural tube defects could have been prevented as of 202112.

“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.”

 

Relevant EUROCAT reports and publications

References

 

  1. MRC Vitamin Study Research Group (1991), "Prevention of Neural Tube Defects: Results of the Medical Research Council Vitamin Study", Lancet, Vol 338, No 8760, pp 131-137.

  2. De Wals, Tairou F, van Allen MI, Lowry SH, Sibbald B, Evans JA, van den Hof MC, Zimmer P, Crowley M, Fernandez B, Lee NS, Niyonsenga T (2007), "Reduction in Neural Tube Defects after Folic Acid Fortification in Canada", N Engl J Med, Vol 357, No 2, pp 135-142.

  3. Botto LD, Lisi A, Bower C, Cranfield MA, Dattani N, de Vigan C, de Walle H, Halliday J, Irgens LM, Lowry RB, McDonnell R, Metneki J, Poetzsch S, Ritvanen A, Robert-Gnansia E, Siffel C, Stoll C, Mastrioacovo P (2006), "Trends of Selected Malformations in Relation to Folic Acid Recommendations and Fortification: An International Assessment", Birth Defects Res A Clin Mol Teratol, Vol 76, No 1, pp 693-705.

  4. Williams LJ, Mai CT, Edmonds LD, Shaw GM, Kirby RS, Hobbs CA, Sever LE, Miller LA, Meaney FJ, Levitt M (2002), "Prevalence of Spina Bifida and Anencephaly During the Transition to Mandatory Folic Acid Fortification in the United States", Teratology, Vol 66, No 1, pp 33-39.

  5. Lopez-Camelo JS, Orioli IM, de Graca Dutra M, Nazer-Herrera J, Rivera N, Ojeda ME, Canessa A, Wettig E, Fontannaz AM, Mellado C, Castilla EE (2005), "Reduction of Birth Prevalence Rates of Neural Tube Defects After Folic Acid Fortification in Chile", Am J Med Genet A, Vol 135, No 2, pp 120-125.

  6. Quinn M, Halsey J, Sherliker P, Pan H, Chen Z, Bennet D, Clarke R (2024), “Global heterogeneity in folic acid fortification policies and implications for prevention of neural tube defecs and stroke: a systematic review”, eClinicalMedicine, Vol 67, pp 102366

  7. Scientific Advisory Committee on Nutrition (2017), "Update on Folic Acid", London, UK.

  8. Garne E, Urhoj SK, Bakker M, et al. (2023), " The quality and the accuracy of codes for terminations of pregnancy for fetal anomalies recorded in hospital databases in three countries in northern Europe.", Birth Defects Res. Vol 115, No 3, pp 405-12.

  9. Morris JK, Addor M-C, Ballardini E, et al. (2021), "Prevention of Neural Tube Defects in Europe: A Public Health Failure.", Frontiers in Pediatrics, Vol 9

  10. Khoshnood B, Loane M, de Walle H, et al. (2015), " Long term trends in prevalence of neural tube defects in Europe: population based study", BMJ, Vol 351

  11. Khoshnood B, Greenlees R, Loane M, Dolk H. (2011), "Paper 2: EUROCAT public health indicators for congenital anomalies in Europe", Birth Defects Res Clin Mol Teratol, 91 Suppl 1(Suppl 1):S16-22.

  12. Morris JK, Addor M-C, Ballardini E, et al. (2021), "Prevention of Neural Tube Defects in Europe: A Public Health Failure.", Frontiers in Pediatrics, Vol 9