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The team led by Babak Khoshnood, Inserm Research Director, set itself the goal of evaluating the long-term trends in the number of cases of defective neural tube closure in Europe.
They analysed data on over 11,000 cases of defects from 28 EUROCAT (European Surveillance of Congenital Anomalies) registries, which cover approximately 12.5 million births in 19 countries between 1991 and 2011. Mathematical models were used in order to compare the differences between the registries. They found that the total prevalence of neural tube defects in 2011 was generally comparable to that observed in 1991 (9 per 10,000 births). This was also true for the two main types of defect, anencephaly and spina bifida. Estimates from the models show a 4% annual increase from 1995 to 1999, and a 3% decrease between 1999 and 2003, followed by a stabilisation in the subsequent years.
Trends for spina bifida and anencephaly were comparable, and no substantial decrease was observed for these two defects.
The authors emphasise that this is an observational study, and that no definite explanation as to cause and effect can therefore be drawn from these results. However, they claim that their data make it possible to conclude that “Recommendations, voluntary fortification, or both have not been effective in decreasing the prevalence of neural tube defects.”
There is no plan in Europe to make it mandatory to add folic acid to some staple foods such as flour or cereals, which happens in many countries such as the United States and Canada. Moreover, studies suggest that this approach increases folic acid intake enough to halve the prevalence of neural tube defects, while no serious side effects have been observed to date.
According to the researchers, the conclusions of this new study “should encourage the relevant European authorities to take a closer look at mandatory fortification.”
Babak Khoshnood Inserm Research Director Inserm Unit 1153 “Sorbonne Paris Cité Research Center in Epidemiology and Biostatistics” Obstetrical, Perinatal, and Pediatric Epidemiology Research Team (EPOPé) Tel.: +33 (0)6 70 77 45 12 Email: babak.khoshnood@inserm.fr
Long term trends in prevalence of neural tube defects in Europe: population based study Babak Khoshnood, senior researcher 1, Maria Loane, lecturer in public health 2, Hermien de Walle, registry leader 3, Larraitz Arriola, epidemiologist 4, Marie-Claude Addor, medical geneticist 5, Ingeborg Barisic, professor 6, Judit Beres, senior researcher in genetics 7, Fabrizio Bianchi, epidemiologist and registry leader 8, Carlos Dias, head of the department of epidemiology 9, Elizabeth Draper, professor of perinatal and paediatric epidemiology 10, Ester Garne, neonatologist and registry leader 11, Miriam Gatt, consultant in public health 12, Martin Haeusler, professor 13, Kari Klungsoyr, professor 14, Anna Latos-Bielenska, professor 15, Catherine Lynch, specialist in public health medicine 16, Bob McDonnell, consultant in public health medicine 17, Vera Nelen, director 18, Amanda J Neville, registry leader 19, Mary T O’Mahony, specialist in public health medicine 20, Annette Queisser-Luft, senior physician 21, Judith Rankin, professor 22, Anke Rissmann, professor of paediatrics 23, Annukka Ritvanen, registry leader and chief physician 24, Catherine Rounding, acting registry leader 25, Antonin Sipek, medical geneticist and neonatologist 26, David Tucker, CARIS registry manager 27, Christine Verellen-Dumoulin, professor 28, Diana Wellesley, consultant in clinical genetics 29, Helen Dolk, professor of epidemiology and health services research 2 1 Obstetrical, Perinatal and Pediatric Epidemiology Research Team, Center for Biostatistics and Epidemiology, INSERM U1153, Maternité de Port-Royal, 75014 Paris, France; 2 EUROCAT Central Registry, Centre for Maternal, Fetal and Infant Research, Institute of Nursing Research, University of Ulster, Newtownabbey, UK; 3 EUROCAT Northern Netherlands Registry, University of Groningen, University Medical Center Groningen, Department of Genetics, Groningen, Netherlands; 4 Public Health Division of Gipuzkoa, Instituto BIO-Donostia Basque Government CIBER Epidemiología y Salud Pública - CIBERESP, San Sebatian, Spain; 5 Service de Genetique Medicale Maternite, CHUV, Lausanne, Switzerland; 6 Children’s University Hospital of Zagreb, Clinical Hospital Sisters of Mercy, Zagreb, Croatia; 7 National Institute of Health Development, Department of Hungarian Congenital Abnormality Registry and Surveillance, Budapest, Hungary; 8 CNR Institute of Clinical Physiology and Tuscany Registry of Congenital Defects, “Gabrielle Monasterio” Foundation, Pisa, Italy; 9Instituto Nacionale de Saude Dr. Ricardo Jorge, Lisbon, Portugal; 10 Departmentof Health Sciences, University of Leicester, Leicester, UK; 11 Hospital Lillebaelt, Kolding, Denmark; 12 Department of Health Information and Research,Guardamangia, Malta; 13 Medical University of Graz, Graz, Austria; 14 Medical Birth Registry of Norway, Norwegian Institute of Public Health and Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway; 15 Department of Medical Genetics, University of Medical Sciences, Poznan, Poland; 16 Public Health Department, HSE South, Lacken, Kilkenny, Ireland; 17 Health Service Executive, Dublin, Ireland; 18 Provincial Institute for Hygiene, Antwerp, Belgium; 19 Registro IMER - IMER Registry (Emilia Romagna Registry of Birth Defects), Center for Clinical and Epidemiological Research, University of Ferrara, Ferrara, Italy; 20 Department of Public Health, Health Service Executive - South, Ireland; 21 Birth Registry Mainz Model, Childrens Hospital, University Medical Center, Johannes Gutenberg-University, Mainz, Germany; 22 Institute of Health and Society, Newcastle University, Newcastle, UK; 23 Malformation Monitoring Centre Saxony-Anhalt, Medical Faculty Otto-von-Guericke University, Magdeburg, Germany; 24 National Institute for Health and Welfare, Helsinki, Finland; 25 National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK; 26 National Registry of Congenital Anomalies of the Czech Republic, Department of Medical Genetics, Thomayer University Hospital, Prague, Czech Republic; 27 Public Health Wales, Swansea, UK; 28 Center for Human Genetics, Institut de Recherche Scientifique en Pathologie et en Génétique, Charleroi, Belgium; 29 University Hospitals Southampton, Faculty of Medicine and Wessex Clinical Genetics Service, Southampton, UK The British Medical Journal
