Prevalence of neural tube defects in England prior to the mandatory fortification of non-wholemeal wheat flour with folic acid: a population-based cohort study

Jennifer M Broughan; Danielle Martin; Thomas Higgins; Gillian Swan; Adrienne Cullum; Jennifer J Kurinczuk; Elizabeth S Draper; Karen Luyt; Diana G Wellesley; Sarah Stevens; Alison Tedstone; Judith Rankin

doi:10.1136/archdischild-2023-325856

Prevalence of neural tube defects in England prior to the mandatory fortification of non-wholemeal wheat flour with folic acid: a population-based cohort study

Arch Dis Child. 2024 Jan 22;109(2):106-112. doi: 10.1136/archdischild-2023-325856.

Authors

Affiliations

¹ National Disease Registration Service (NDRS), NHS England, Redditch, UK jennifer.broughan@nhs.net.
² National Disease Registration Service (NDRS), NHS England, Redditch, UK.
³ Office for Health Improvement and Disparities, United Kingdom Department of Health and Social Care, London, UK.
⁴ National Perinatal Epidemiology Unit, University of Oxford, Oxford, UK.
⁵ Health Sciences, University of Leicester, Leicester, UK.
⁶ Translational Health Sciences, University of Bristol Medical School, Bristol, UK.
⁷ Psychology, Southampton University Hospitals Trust, Southampton, UK.
⁸ Institute of Health & Society, Newcastle University, Newcastle, UK.

Abstract

Objectives: To determine the baseline trends in the total birth prevalence of neural tube defects (NTDs) in England (2000-2019) to enable the impact of folic acid fortification of non-wholemeal wheat flour to be monitored.

Design: Population-based, observational study using congenital anomaly (CA) registration data for England curated by the National Congenital Anomaly and Rare Disease Registration Service (NCARDRS).

Setting: Regions of England with active registration in the time period.

Participants: Babies that were liveborn or stillborn and pregnancies that resulted in a termination of pregnancy or a late miscarriage (20-23 weeks' gestation) with an NTD.

Main outcome measures: Total birth prevalence of anencephaly, spina bifida and all NTDs in England. Poisson regression analysis was used to evaluate time trends with regional register as a random effect. The progress of national registration across England was assessed.

Results: There were 4541 NTD pregnancies out of 3 637 842 births in England; 1982 anencephaly and 2127 spina bifida. NTD prevalence was 12.5 (95% CI 12.1 to 12.9) per 10 000 total births. NTD prevalence per 10 000 total births was significantly higher in 2015-2019 (13.6, 95% CI 12.9 to 14.4) compared with 2010-2014 (12.1, 95% CI 11.7 to 12.5). An increasing trend in NTDs overall was detected (incidence rate ratio (IRR) 1.01, 1.00 to 1.02), although further analysis determined this effect was confined to 2015-2019 (compared against 2000-2004, IRR 1.14, 1.04 to 1.24). The birth prevalence of anencephaly reflected this pattern. The prevalence of spina bifida remained relatively stable over time.

Conclusions: Baseline NTD prevalence for England has been established. National and standardised CA registration is in place, facilitating the systematic and consistent monitoring of pre-fortification and post-fortification NTD trends and evaluating the impact of fortification on NTD prevalence.

Keywords: Child Health; Epidemiology; Paediatrics.

Publication types

Observational Study

MeSH terms

Anencephaly* / epidemiology
Anencephaly* / prevention & control
Cohort Studies
Female
Flour
Folic Acid
Food, Fortified
Humans
Neural Tube Defects* / epidemiology
Neural Tube Defects* / prevention & control
Pregnancy
Prevalence
Spinal Dysraphism* / epidemiology
Spinal Dysraphism* / prevention & control
Triticum

Substances

Folic Acid