Prof Michael Turner Addresses Oireachtas Committee on Health
Full statement by Professor Michael Turner, UCD Professor of Obstetrics and Gynaecology and Director, UCD Centre for Human Reproduction, Coombe Women and Infants University Hospital:
Chairperson, Members of the Committee I thank you for the invitation to discuss the pregnancy complication of Neural Tube Defects which is a major public health issue of national importance.
Neural Tube Defects (NTDs) are a group of serious congenital neurodevelopment malformations due to the incomplete closure of the neural tube within a month of conception. The reported prevalence varies from 0.05 to 6.0 per thousand births with regional and population specific variations (EUROCAT Network 2008-12, McKeating et al, 2015).
Anencephaly is incompatible with life. Death before birth is common and survival beyond the first week of life rare. Spina bifida and encephalocoele both have a high perinatal and infant mortality. Although 80% of infants with spina bifida survive, the condition is associated with varying degrees of disability. NTDs carry a high a heavy burden of illness for the individual, their parents and families and, incidentally, for the health services.
Some NTDs are genetic in origin but landmark studies from the 1990’s have shown that about two thirds are preventable by increasing the mother’s consumption of folic acid (FA) before and during the early days of pregnancy.
There are three possible sources of folate.
Folate is found naturally in a wide variety of foods, including vegetables (especially dark green leafy vegetables), fruits and fruit juices, nuts, beans, peas, dairy products, poultry and meat, eggs, seafood and grains (NIH Office of Dietary Supplements, 2015). Spinach, liver, yeast, asparagus and Brussels sprouts are among the foods with the highest levels of folate.
The bioavailability of folate from food is limited and it is strongly influenced by various methods of cooking which degrade the natural forms of the vitamin (McKillop et al, 2002). For example, typical boiling times half the folate content of spinach and broccoli whereas steaming is associated with markedly greater folate retention.
While there are methodological challenges estimating accurately dietary folate intake, the bioavailability of folate from food is 50-98% of that for synthetic Folic Acid (Obeid et al, 2014). During pregnancy, demands for folate increase due its role in nucleic acid synthesis and, therefore, the Recommended Daily Allowance (RDA) is increased by 50%. It is difficult even for any woman on a healthy diet cooked appropriately to achieve the RDA through dietary means alone (NIH, 2015).
B. Folic acid supplements
Based on scientific evidence gathered over the last twenty years, it is recommended that the optimum dose of supplemental FA for the presentation of NTDS is 400µg orally per day which is readily available in all pharmacists over the counter (Cawley et al, in press).
However, women who are at increased risk of NTDs should take a dose of 5mg orally per day which requires a prescription before it is dispensed.
C. Food fortification.
This may be mandatory or voluntary. In North America, food fortification with FA is mandatory and this has been associated with a decrease in the incidence of NTDs, albeit the reduction has been less than had been hoped. In Ireland and the rest of the European Union food fortification with FA is voluntary. As the incidence of NTDs had been falling, the Irish Government decided not to mandate fortification following a report from the Food Safety Authority of Ireland in 2008.
A. Ireland has a higher rate of NTDs than other European countries, although rates have fallen over recent decades. However, a recent comprehensive national study found that the incidence in the Republic of Ireland had increased significantly from 0.92/1000 in 2005-6 to 1.17/1000 in 2009-11 (McDonnell et al, 2015). Of the 236 cases over three years, 49% (n=115) had spina bifida, 45% (n=106) had anencephaly and 6% (n=15) had an encephalocoele. Of the 94 babies born with spina bifida, 90.4% survived the neonatal period. The incidence of NTDs was lower in Dublin compared with other regions. The increase in the incidence may be explained by better case ascertainment in the recent study. However, more recent publications from Dublin suggest otherwise.
B. Except Sweden, food fortification with FA by manufacturers in European countries including Ireland is voluntary. Three audits were conducted of fortified foods available in supermarkets in the Republic of Ireland (Kelly et al, 2015). Researchers visited six of the top supermarkets by market share in Dublin and obtained the FA levels from nutrition levels in 2004, 2008 and 2013/4. They identified 650 food items and found that the percentage of foods fortified with FA has decreased and that bread, milk and spreads no longer contain as much FA as in 2004 and 2008.
C. In a retrospective analysis of trends in FA supplementation among women booking for antenatal care between 2009 and 2013, a study from the UCD Centre of Human Reproduction at the Coombe found that the periconceptual rate of FA supplementation decreased significantly from 45.1% in 2009 to 43.1% in 2013 (McKeating et al, 2015). The decrease over the five years was more likely to occur in women who had children before, who were aged 30-39 years, who were obese and who had been born in Ireland.
D. In a prospective study from the UCD Centre of 564 women booking for antenatal care at the Coombe, only one in four took FA for greater than 12 weeks before pregnancy as is ideal (Cawley et al, 2015). Women who planned their pregnancy or who were having their first baby baby were more likely to take prepregnancy FA.
E. In a review from the UCD Centre which has been accepted for publication, we found that there is inconsistency across national and international guidance given to women about FA supplementation and that European guidelines, in particular, need to updated in the light of more recent scientific evidence (Cawley et al, in press).
The UCD Centre has recently received a research grant from Safefood to conduct an all-island study to measure red cell folate levels in women booking for antenatal care in Dublin, Cork and Belfast.
The Food Safety Authority of Ireland is presently preparing a report for the Minister of Health on food fortification with FA.
What needs to happen next?
1. The national guidance to women of childbearing age needs to be updated.
All women who could potentially become pregnant within the next year should be taking FA supplements every day (and not just women who are planning to become pregnant). Ideally women should start FA at least three months before they conceive and continue for three months after they conceive.
Women who are at increased risk of NTDs should be taking high dose FA as prescribed by their doctor (and not just over-the-counter low dose FA). This includes women with a history of NTDS, obese women, women with diabetes mellitus, and women on certain medications.
2. We need a renewed public health campaign to increase awareness about the potential of FA to prevent NTDs. This campaign needs to prioritise groups of women who are particularly vulnerable.
Healthcare professionals nationally and internationally need to be consistent in their communications and to highlight the importance of prepregnancy supplementation.
Women of childbearing age use smart phones extensively to access pregnancy-related information. Thus, future campaigns should use social media as well as traditional communication channels.
3. The issue of mandatory food fortification with FA needs to be reviewed urgently by the Government and this has implications for different Departments. As food and food ingredients are now sourced globally this issue would benefit, in my view, from a pan-European approach to the regulation and subsequent monitoring of all food fortification. In the meantime, I recommend that there is an improvement in communications about voluntary FA fortification between the food industry and both women and healthcare professionals.
Professor Michael Turner
UCD Professor of Obstetrics and Gynaecology
Director, UCD Centre for Human Reproduction
Coombe Women and Infants University Hospital
McKeating A, Farren M, Cawley S, Daly N, McCartney D, Turner MJ.
Maternal folic acid supplementation trends 2009 – 2013.
Acta Obstet Gynecol Scand 2015; 94: 727–733.
Cawley S, Mullaney L, Mc Keating A, Farren M, McCartney D, Turner MJ
An analysis of folic acid supplementation in women presenting for antenatal care.
J Public Health 2015 doi: 10.1093/pubmed/fdv019
Cawley S, Mullaney L, McKeating A, Farren M, McCartney D, Turner MJ.
A review of European guidelines on periconceptional Folic Acid supplementation.
EU J Clin Nutr (in press)
Kelly F, Gibney ER, Boilson A, Staines A, Sweeney MR.
Folic acid levels in some food staples in Ireland are on the decline: implications for passive folic acid intakes.
J Public Health (Oxf) 2015 [Epub ahead of print].
McDonnell R, Delany V, O’Mahony MT, Mullaney C, Lee B, Turner MJ.
Neural tube defects in the Republic of Ireland in 2009–11.
J Public Health (Oxf) 2015;37:57-63.
McKillop DJ, Pentieva K, Daly D, McPartlin JM, Hughes J, Strain JJ, Scott JM, McNulty H.
The effect of different cooking methods on folate retention in various food that are amongst the major contributors to folate intake in the UK diet.
Br J Nutri 2002;88:681-8.
Obeid R, Koletzko B, Pietrzik K.
Clin Nutr 2014;33:252-9.
Report of the Implementation Group on Folic Acid Food Fortification to the Department of Health and Children.
Food Safety Authoriy of Ireland www.fsai.ie