Neural tube defects in Costa Rica, 1987-2012: origins and development of birth defect surveillance and folic acid fortification

Orofacial clefts in Costa Rica, 1996-2021: Analysis of surveillance data

BACKGROUND

Orofacial clefts (OFCs) are among the most common birth defects (BD). In 2008, a series of improvements began in the Costa Rican Birth Defect Register Center (CREC). We aim to explore trends between 1996 and 2021.

METHODS

A trend analysis of OFCs from 1996 to 2021 and a descriptive analysis of OFCs from 2010 to 2021 were performed based on data from the CREC, the national BD surveillance system. Prevalence at birth was calculated according to the type: cleft palate (CP), cleft lip with or without CP (CL ± P), and presentation (isolated, multiple non-syndromic, or syndromes). We used joinpoint regression to identify if a significant change in trend occurred; the average annual percent change (AAPC) was determined. Marginal means and prevalence ratios by subperiod (1996-2009 as referent and 2010-2021) were estimated using Poisson regression and compared using Wald's chi-square tests (α ≤.05).

RESULTS

We found a significant AAPC for OFCs prevalence of +1.4: +0.6 for isolated, +2.9 for multiple non-syndromic, and +7.7 for syndromes (p < .05). When comparing the OFC's prevalence of the subperiod 2010-2021 (11.86 per 10,000) with 1996-2009 (9.36 per 10,000) the prevalence ratio was 1.3 (p < .01): 1.1 (p < .05) for isolated, 1.6 (p < .01) for multiple non-syndromic, and 3.3 (p < .01) for syndromes. The prevalence of OFCs from 2010 to 2021 was 9.1 for CL ± P and 2.8 for CP. Seventy-one percent of the OFCs were isolated, 22% multiple non-syndromic, and 7% syndromes.

CONCLUSION

The trend in OFCs' prevalence is toward increasing, mainly due to improvements in the surveillance system.

Tracking the Global Burden of Neural Tube Defects and Assessing Disparities Across World Health Organization Regions: A Scoping Literature Review

BACKGROUND AND OBJECTIVES

Neural tube defects (NTDs) are an important cause of global morbidity worldwide. Well-planned global neurosurgery and public health efforts can aid vulnerable communities, but there is a need to elucidate the global burden of NTDs and identify regions without available data to better target interventions.

METHODS

A scoping review to quantify worldwide NTD prevalence using the PubMed/Medline and birth defects surveillance registries was conducted. Data published after January 1, 1990, encompassing prevalence values of at least the 2 most prevalent NTDs-spina bifida and encephalocele-were abstracted. Average NTD prevalence rates were aggregated by World Health Organization (WHO) region and World Bank classification, and differences were determined using the analysis of variance test. Differences in availability of nationally representative data by WHO region and World Bank classification were determined using χ2 tests.

RESULTS

This review captured 140 studies from a total of 93 of 194 WHO member countries. The percentage of countries within a geographic region with available NTD prevalence data was highest in the Eastern Mediterranean (EMR) (85.7%) and lowest in Africa (AFR) (31.3%). The NTD prevalence range was 0.9-269.6 per 10 000 births. Statistically significant differences in reported NTD prevalence rates existed by WHO Region (P = .00027) and World Bank income level of study country (P = .00193). Forty countries (43%) had conducted national-level studies assessing NTD prevalence. There was a statistically significant difference in the availability of nationally representative prevalence data depending on the WHO region (P = .0081) and World Bank classification of study country (P = .0017).

CONCLUSION

There is a gap in availability of NTD prevalence data worldwide, with many WHO member states lacking national-level NTD prevalence estimates. These findings highlight the need for greater NTD surveillance efforts to identify the countries with the greatest need for targeted global intervention.

Implementation factors of non-communicable disease policies and programmes for children and youth in low-income and middle-income countries: a systematic review

INTRODUCTION

Despite declared life-course principles in non-communicable disease (NCD) prevention and management, worldwide focus has been on older rather than younger populations. However, the burden from childhood NCDs has mounted; particularly in low-income and middle-income countries (LMICs). There is limited knowledge regarding the implementation of paediatric NCD policies and programmes in LMICs, despite their disproportionate burden of morbidity and mortality. We aimed to understand the barriers to and facilitators of paediatric NCD policy and programme implementation in LMICs.

METHODS

We systematically searched medical databases, Web of Science and WHOLIS for studies on paediatric NCD policy and programme implementation in LMICs. Screening and quality assessment were performed independently by researchers, using consensus to resolve differences. Data extraction was conducted within the WHO health system building-blocks framework. Narrative thematic synthesis was conducted.

RESULTS

93 studies (1992-2020) were included, spanning 86 LMICs. Most were of moderate or high quality. 78% reported on paediatric NCDs outside the four major NCD categories contributing to the adult burden. Across the framework, more barriers than facilitators were identified. The most prevalently reported factors were related to health service delivery, with system fragmentation impeding the continuity of age-specific NCD care. A significant facilitator was intersectoral collaborations between health and education actors to deliver care in trusted community settings. Non-health factors were also important to paediatric NCD policies and programmes, such as community stakeholders, sociocultural support to caregivers and school disruptions.

CONCLUSIONS

Multiple barriers prevent the optimal implementation of paediatric NCD policies and programmes in LMIC health systems. The low sociopolitical visibility of paediatric NCDs limits their prioritisation, resulting in fragmented service delivery and constraining the integration of programmes across key sectors impacting children, including health, education and social services. Implementation research is needed to understand specific contextual solutions to improve access to paediatric NCD services in diverse LMIC settings.

Population-based prevalence and trend of birth defects in Costa Rica from 2000 to 2019

BACKGROUND

We aimed to analyze the prevalence and trend of birth defects (BDs) in Costa Rica, where BDs are the second leading cause of infant and under-five mortality.

METHODS

A descriptive analysis of selected BDs prevalence and trends from 2000 to 2019 was performed, based on data from the Costa Rican Birth Defects Register Center, the national BDs surveillance system with coverage of 98% of live births in the country. We used Joinpoint regression to identify any calendar year where a significant change in trend occurred; the annual percent change (APC) and the average annual percent change (AAPC) were determined. Marginal means and prevalence ratios by subperiod (2000-2009 as referent and 2010-2019) were estimated using Poisson regression, and compared using Wald's chi-square tests (alpha ≤0.05).

RESULTS

From 2000 to 2019, BDs occurred in 2.3% of live births (95% CI: 2.3-2.4); 73% of which were major BDs. Males presented a significantly higher prevalence (sex ratio 1.13 males/females). The trend showed an AAPC of +3.7 (p < .05) with two joinpoints, 2005 and 2013. A significant APC (+11.3) was observed during 2005-2013, within the context of improvements in the surveillance system, such as the increase in the reporting age, and the incorporation of other data sources in addition to maternity hospitals. Most of the BDs groups presented a significant upward trend. The highest AAPC was observed for the respiratory system (+11.7), congenital heart defects (+9.5), and nervous system (+8.5).

CONCLUSIONS

The BDs present a clear upward trend in the last two decades due, among other things, to a significant improvement in the surveillance system.

Global strategies for the prevention of neural tube defects through the improvement of folate status in women of reproductive age

INTRODUCTION

Neural tube defects represent a global public health problem, mainly in countries where effective prevention strategies are not yet in place. The global prevalence of neural tube defects is estimated at 18.6/10,000 (uncertainty interval: 15.3-23.0) live births, where ~ 75% of cases result in under-five mortality. Most of the mortality burden is in low- and middle-income countries. The main risk factor for this condition is insufficient folate levels in women of reproductive age.

METHODS

This paper reviews the extent of the problem, including the most recent global information on folate status in women of reproductive age and the most recent estimates of the prevalence of neural tube defects. Additionally, we provide an overview of the available interventions worldwide to reduce the risk of neural tube defects by improving folate status in the population, including dietary diversification, supplementation, education, and fortification.

RESULTS

Large-scale food fortification with folic acid is the most successful and effective intervention to reduce the prevalence of neural tube defects and associated infant mortality. This strategy requires the coordination of several sectors, including governments, the food industry, health services providers, the education sector, and entities that monitor the quality of the service processes. It also requires technical knowledge and political will. An international collaboration between governmental and non-governmental organizations is essential to succeed in saving thousands of children from a disabling but preventable condition.

DISCUSSION

We propose a logical model for building a national-level strategic plan for mandatory LSFF with folic acid and explain the actions needed for promoting sustainable system-level change.

Pre and postnatal care characteristics and management features of children born with myelomeningocele in the post-folate fortification era of staple foods in Costa Rica (2004-2022)

PURPOSE

To describe the clinical characteristics of pre- and postnatal care of children born with myelomeningocele in Costa Rica from 2004 to 2022 after the introduction of mandatory fortification of four major staple foods, describing the clinical features of this cohort including the size of the meningomyelocele, neurological level, presence of symptomatic Chiari II at birth, kyphosis, and the severity of hydrocephalus requiring cerebrospinal fluid (CSF) shunting. These results were compared against the pre-fortification historical data to determine favorable outcomes from this health policy.

METHODS

We performed a retrospective review of the clinical records of patients with myelomeningocele at the spina bifida clinic from the National Children's Hospital of Costa Rica who were born between 2004 and 2022, a period when staple food fortification was implemented in the country for four food staples (wheat and corn flour, rice, and dairy products). Pre and postnatal care data pertaining to the number of obstetric ultrasound studies, the trimester in which they were performed, the detection of myelomeningocele and associated hydrocephalus, gestational age and route of delivery, neurological level, myelomeningocele defect size, associated kyphosis and symptomatic Chiari II malformation at birth, time periods of myelomeningocele repair, and CSF shunting were examined. A descriptive comparative frequency analysis between myelomeningocele (MMC) defect size, CSF shunt insertion, symptomatic Chiari II, and kyphosis between the different functional levels was performed with the estimation of the Fisher's exact chi-square test by contingency tables, and 0.05 was set as significance level. Additionally, the postnatal features of this cohort were compared against pre-fortification historical data obtained from 100 live-born patients between 1995 and 1996.

RESULTS

A total of 215 patients that were live born between 2004 and 2022 were eligible for analysis with a follow up ranging from 1 to 19 years (median follow up: 7.9 years). Among 99.1% of the mothers of patients who had prenatal consultations, 95.8% had an average of 3.8 obstetric ultrasound studies which led to a 59% prenatal detection rate of myelomeningocele. The pre and post fortification features showed a male/female ratio that changed from 0.92 to 1.25 respectively. Among these newborns, there was an increase from 54 to 64% cesarean sections as method for delivery. Only 26% of the pre fortification patients had the MMC defect repaired in the first 24 h, 32% from 24 to 72 h, 20% from 72 h to 1 week, and 22% later than 10 days respectively which deeply contrasted with the post fortification cohort where 7.5% had the MMC defect repaired in less than 8 h, 12.2% from 8 to 12 h, 66.5% 12-24 h, and 12.7% from 24 to 48 h and 1% later than 48 h, respectively (P < 0.01). Regarding the post fortification myelomeningocele anatomic and functional characteristics, defect size was measured as less than 3 cm in 7% of cases, 3 to 5 cm in 50% of cases, 5 to 7 cm in 42% of cases, and greater than 7 cm in 1% of cases. Thirteen percent of the cases had paraplegia due to a thoracic level, 10% had a high lumbar level, 58% had a middle lumbar level, 13% a lower lumbar level, and 6% only sacral compromise. When the data from the pre and post fortification cohorts were adjusted and compared, there was a reduction from thoracic/high lumbar cases from 26 to 23% (P < 0.56), with an increase of middle lumbar cases from 43 to 58% and a reduction from 25 to 13% of low lumbar cases (P < 0.01) while there was no change in the 6% percentage of sacral cases respectively. Lesions that were considered too extensive or larger than 7 cm decreased from 7 to 1% while associated kyphotic deformities decreased from 6 to 1.4% (P < 0.01); symptomatic Chiari II malformation at birth also decreased from 7 to 2% in the pre- and post-fortification cohorts respectively with all these changes being statistically significant (P < 0.01). Seventy-nine percent and 80% of the pre and post FAF cohorts required CSF VP shunting with a mean time for insertion of 10 days after spinal defect closure with no significant statistical change between the two groups.

CONCLUSIONS

This study describes a four-staple folate fortified population of live-born patients with myelomeningocele lesions whose neurological level, defect size, and associated deformities such as spinal kyphosis and symptomatic Chiari II at birth suggest that folate fortification could have diminished the severity of this congenital disease.

Folic Acid and the Prevention of Birth Defects: 30 Years of Opportunity and Controversies

For three decades, the US Public Health Service has recommended that all persons capable of becoming pregnant consume 400 μg/day of folic acid (FA) to prevent neural tube defects (NTDs). The neural tube forms by 28 days after conception. Fortification can be an effective NTD prevention strategy in populations with limited access to folic acid foods and/or supplements. This review describes the status of mandatory FA fortification among countries that fortify (n = 71) and the research describing the impact of those programs on NTD rates (up to 78% reduction), blood folate concentrations [red blood cell folate concentrations increased ∼1.47-fold (95% CI, 1.27, 1.70) following fortification], and other health outcomes. Across settings, high-quality studies such as those with randomized exposures (e.g., randomized controlled trials, Mendelian randomization studies) are needed to elucidate interactions of FA with vitamin B12 as well as expanded biomarker testing.

Neural tube defect prevalence does not increase after modification of the folic acid fortification program in Chile

BACKGROUND

In 2000, Chile's Ministry of Health mandated fortification of wheat flour with folic acid at a concentration of 2.2 mg/kg to prevent neural tube defects (NTDs), resulting in a 50% reduction in NTD prevalence. Concerns about possible collateral effects of high folic acid intake led, in 2009, to decrease the folic acid fortification to 1.8 mg/kg of flour. Our study evaluated the impact of this modification on the prevalence of NTDs in Santiago.

METHODS

This study measured the prevalence of NTDs in live births and stillbirths born in Santiago. We calculated prevalence ratios (PR) and 95% confidence intervals (CI) between pre-folic acid fortification (1999-2000), post-folic acid fortification (2001-2009), and post-modified folic acid fortification (2010-2015) periods for all NTDs and their specific types. We used chi-square tests to analyze proportions, and a Joinpoint regression to visualize prevalence time trends.

RESULTS

The NTD prevalence for the period 2001-2015 was 8.9 per 10,000 births, which represents a 48% reduction (PR = 0.52; 95% CI = 0.45-0.61; p < .001) from the pre-folic acid fortification period. During 2010-2015, the NTD prevalence was 9.5/10,000 births, which was higher, but not statistically significantly different from 2001 to 2009 prevalence of 8.6/10,000 (PR = 1.11; 95% CI = 0.96-1.30, p = .17).

CONCLUSIONS

Decreasing the concentration of folic acid fortification was not associated with a statistically significant change in the prevalence of NTDs. Mandatory folic acid fortification continues to be a safe and highly effective policy to prevent NTDs. Future studies should evaluate the prevalence of NTDs across Chile and adherence to folic acid fortification mandates.

Food Fortification With Folic Acid for Prevention of Spina Bifida and Anencephaly: The Need for a Paradigm Shift in Evidence Evaluation for Policy-Making

Context-specific evidence evaluation is advocated in modern epidemiology to support public health policy decisions, avoiding excessive reliance on experimental study designs. Here we present the rationale for a paradigm shift in evaluation of the evidence derived from independent studies, as well as systematic reviews and meta-analyses of observational studies, applying Hill's criteria (including coherence, plausibility, temporality, consistency, magnitude of effect, and dose-response) to evaluate food fortification as an effective public health intervention against folic acid-preventable (FAP) spina bifida and anencephaly (SBA). A critical appraisal of evidence published between 1983 and 2020 supports the conclusion that food fortification with folic acid prevents FAP SBA. Policy-makers should be confident that with mandatory legislation, effective implementation, and periodic evaluation, food fortification assures that women of reproductive age will safely receive daily folic acid to significantly reduce the risk of FAP SBA. Current evidence should suffice to generate the political will to implement programs that will save thousands of lives each year in over 100 countries.

Evaluating an intervention for neural tube defects in coal mining cites in China: a temporal and spatial analysis

BACKGROUND

Neural tube defects (NTDs) are congenital birth defects of the central nervous system that affect 0.5-2 per 1000 pregnancies worldwide. Therefore effective interventions for birth defects, especially NTDs, are very important.

METHODS

Yuanping City is a coal mining city in Shanxi Province, China, with a high incidence of NTDs. This study evaluates the effects of NTD interventions in this city after adjusting for covariates that characterize the native environment. The number of NTD cases and births for the 18 towns in Yuanping City from 2007 to 2014 were included in the study. A shared-component zero-inflated Poisson regression was applied to analyse the temporal-spatial variance among the incidence rates of NTDs in Yuanping City before and after the interventions.

RESULTS

The results showed that existing interventions to mitigate birth defects, such as folic acid supplementation, reduced the incidence of NTDs by 53.5% in coal mining areas in Yuanping City. However, the NTD risk in areas near coal mines, especially unrestored coal mines, was still high, even after the intervention.

CONCLUSIONS

The government should focus on health hazards related to mining and agricultural production and should provide education and resources to reduce environmental exposure. Reducing environmental risks should be regarded as an early intervention strategy to mitigate birth defects.

Incidence of neural tube defects and their risk factors within a cohort of Moroccan newborn infants

Background

Neural tube defects (NTDs) are a group of birth defects that result from a partial or complete failure of the neural tube to close during embryogenesis. Their prevalence varies between 0.5 to 2 per 1000 births in countries without folic acid supplementation. The aim of our study is to assess the NTDs incidence and describe the risk factors within Moroccan newborn infants.

Method

This is a descriptive study over a period of 5 and a half years including all births at “Les Orangers” Maternity and Reproductive Health Hospital of Rabat with notification of NTD cases, whether isolated or combined with other anomalies. Data were reported on pre-established sheets and on the teratovigilance registry. Statistical analysis was performed with SPSS version 18 statistical software.

Results

During the study period, 43,923 births were recorded including 44 cases of neural tube defects, an incidence rate of 1 per 1000 births, with a female predominance; sex ratio = 0.8. These defects included anencephaly (50%), spina bifida (38.6%) and encephalocele (11.4%). The risk factors detected during this study include consanguinity (34%), consumption of fenugreek or other plants (36%), diabetes (4.5%) and medication (2.2%). A family history of malformation was reported in 6.8% of cases and among siblings in 4.5% of cases. The average maternal age was 30.38 ± 6.88 and the average gestational age was 36.80 ± 5.11. A quarter of mothers did not benefit from any medical monitoring during pregnancy while 59% did not take folic acid supplementation during the first trimester of pregnancy and none of them took B9 vitamin during the periconceptional period. The antenatal diagnosis was performed in 63% of cases. The mortality rate was 3.8 per 10,000 and 16% of cases evolved positively.

Conclusion

NTDs require high intensity and multidisciplinary care which stresses the importance, in our context, of strengthening and optimizing acid folic supplementation strategies during the periconceptional period.

Folate fortification and supplementation in prevention of folate-sensitive neural tube defects: a systematic review of policy

OBJECTIVE

Neural tube defects (NTDs) are common congenital neurological defects, resulting in mortality, morbidity, and impaired quality of life for patients and caregivers. While public health interventions that increase folate consumption among women who are or plan to become pregnant are shown to reduce folate-sensitive NTDs, public health policy reflecting the scientific evidence lags behind. The authors aimed to identify the types of policies applied, associated outcomes, and impact of folate fortification and supplementation on NTDs worldwide. By identifying effective legislation, the authors aim to focus advocacy efforts to more broadly effect change, reducing the burden of NTDs in neurosurgery.

METHODS

A systematic review was conducted exploring folate fortification and supplementation policies using the PubMed and Scopus databases. Titles and abstracts from articles identified were read and selected for full-text review. Studies meeting inclusion criteria were reviewed in full and analyzed for study design, aim, population, interventions, and outcomes.

RESULTS

Of 1637 resultant articles, 54 were included. Mandatory folate fortification was effective at reducing folate-sensitive NTDs. Mandatory fortification also decreased hospitalization rates and deaths after discharge and increased 1st-year survival for infants with NTDs. Recommended folate supplementation also resulted in decreased NTDs; however, issues with compliance and adherence were a concern and impacted effectiveness. Folate fortification and/or supplementation resulted in decreased NTD prevalence, although more change was attributed to fortification. Dual policies may hold the most promise. Furthermore, reductions in NTDs were associated with significant cost savings over time.

CONCLUSIONS

Both mandatory folate fortification and recommended supplementation policies were found to effectively decrease folate-sensitive NTD rates when applied. A comprehensive approach incorporating mandatory folate fortification, appropriate folate supplementation, and improved infrastructure and access to prenatal care may lead to decreased NTDs worldwide. This approach should be context-specific, emphasize education, and account for regional access to healthcare and social determinants of health. With wide implications for NTDs, associated health outcomes, quality of life of patients and caregivers, and economic impacts, policy changes can drastically improve global NTD outcomes. As caretakers of children with NTDs, the authors as neurosurgeons advocate for a comprehensive policy, the engagement of stakeholders, and a broader global impact.

Modeling shows high potential of folic acid-fortified salt to accelerate global prevention of major neural tube defects

BACKGROUND

We estimated the global proportion of folic acid-preventable spina bifida and anencephaly (FAP SBA) potentially prevented through mandatory double fortification of iodized salt with folic acid.

METHODS

Using United Nations Children's Fund (UNICEF) and Global Fortification Data Exchange (GFDx) data sets, we modeled country-specific number of FAP SBA cases prevented annually using (a) current coverage of the salt in households worldwide and (b) expected daily amount of folic acid intake from folic acid-fortified iodized salt. Our evidence-based modeling strategy assumed mandatory folic acid fortification of salt at 20 ppm, and that at 200 μg/day intake of folic acid through fortified salt, should achieve 100% prevention of all FAP SBA in countries.

RESULTS

One hundred countries that have data on percent of households consuming iodized salt globally were examined; 55 of them have ≥80% households consuming iodized salt. Our model estimated approximately 180,000 cases of FAP SBA could be prevented in these 100 countries through folic acid-fortified iodized salt, and 150,000 of them would be in countries where ≥80% households consuming iodized salt that can be potentially fortified with folic acid. Salt fortification with folic acid could contribute to the prevention of about 65% global FAP SBA cases annually.

CONCLUSIONS

Our evidence-based model shows that there is high potential to prevent FAP SBA using folic acid-fortified iodized salt. Prevention will reach countries where there is a limited reach of centrally processed folic acid-fortified wheat or maize flour. If this intervention is made feasible by the salt industry, it can accelerate the prevention of FAP SBA significantly.

Genetic variants in GRHL3 and risk for neural tube defects: A case-control and case-parent triad/control study

BACKGROUND

Neural tube defects (NTDs) are the most common severe birth defects with complex etiologies. Previous studies conducted on animals have suggested that the Grhl3 gene is essential for closure of the spinal neural tube, but little evidence from human studies on the variants of GRHL3 gene has been provided, especially the common genetic variants.

METHODS

To investigate the relationship between common genetic variants of GRHL3 and the risk for NTDs, we performed a case-control study and a case-parent triad/control study. Fast-target enrichment sequencing was performed to screen exon regions from 503 NTD cases, and three tag SNPs (single nucleotide polymorphisms, including rs12030057, rs2486668, and rs545809) were selected according to the sequencing results. Then, Sequenom MassARRAY genotyping was performed in 757 case parents and 519 controls to obtain genotype information of the target variant sites among all NTD triads and controls.

RESULTS

The genotype distributions of all SNPs were in accordance with Hardy-Weinberg Equilibrium (HWE) in the control population. In the case-control study, significant associations were found between C27G genetic variants on rs2486668 and risk for spina bifida and encephalocele, respectively, under different genetic models. Consistently, in the case-parent triad/control study, GG genotype on rs2486668 was associated with increased risk for spina bifida, with a RR of 2.15 (95% CI: 1.20-3.83). However, no parent-of-origin effect was found for any tag SNPs.

CONCLUSION

The GRHL3 C67G missense variant may increase the risk for spina bifida and encephalocele phenotypes.

Modelling the impact of mandatory folic acid fortification of bread or flour in Ireland on the risk of occurrence of NTD-affected pregnancies in women of childbearing age and on risk of masking vitamin B12 deficiency in older adults

PURPOSE

The rate of neural tube defects (NTDs) in Europe has remained similar since the 1990s despite folic acid supplement recommendations (400 µg/day) for women of childbearing age. Mandatory folic acid fortification of staple foods has proved effective for reducing the prevalence of NTDs in over 80 countries. This study estimated the impact of addition of folic acid to bread or flour in the Republic of Ireland on reducing the risk of occurrence of NTD-affected pregnancies and the possible risk of masking (undiagnosed) vitamin B₁₂ deficiency in older adults.

METHODS

Analyses were based on the Irish National Adult Nutrition Survey (2008-2010). Folic acid fortification was modelled using DaDiet© software. Estimates were made of the increase in average daily folic acid intake in women (18-50 years) and the risk of exceeding the tolerable upper intake level (UL) of 1000 µg for folic acid in adults over 50 years of age.

RESULTS

The fortification scenarios examined would reduce the risk of NTD-affected pregnancies by 8-32%, corresponding to an increase of 39-152 μg in the mean daily folic acid intake of WCBA. The risk of masking anaemia associated with vitamin B₁₂ deficiency in older adults would be negligible as the probability of exceeding the UL for folic acid, even by a small amount, is very low (≤ 0.2%).

CONCLUSIONS

These levels of addition of folic acid to bread or flour would effectively reduce the risk of NTDs while allowing safe consumption of folic acid at current levels from other fortified foods and supplements.

Who Should Be Targeted for the Prevention of Birth Defects? A Latent Class Analysis Based on a Large, Population-Based, Cross-Sectional Study in Shaanxi Province, Western China

Background

The wide range and complex combinations of factors that cause birth defects impede the development of primary prevention strategies targeted at high-risk subpopulations.

Methods

Latent class analysis (LCA) was conducted to identify mutually exclusive profiles of factors associated with birth defects among women between 15 and 49 years of age using data from a large, population-based, cross-sectional study conducted in Shaanxi Province, western China, between August and October, 2013. The odds ratios (ORs) and 95% confidence intervals (CIs) of associated factors and the latent profiles of indicators of birth defects and congenital heart defects were computed using a logistic regression model.

Results

Five discrete subpopulations of participants were identified as follows: No folic acid supplementation in the periconceptional period (reference class, 21.37%); low maternal education level + unhealthy lifestyle (class 2, 39.75%); low maternal education level + unhealthy lifestyle + disease (class 3, 23.71%); unhealthy maternal lifestyle + advanced age (class 4, 4.71%); and multi-risk factor exposure (class 5, 10.45%). Compared with the reference subgroup, the other subgroups consistently had a significantly increased risk of birth defects (ORs and 95% CIs: class 2, 1.75 and 1.21–2.54; class 3, 3.13 and 2.17–4.52; class 4, 5.02 and 3.20–7.88; and class 5, 12.25 and 8.61–17.42, respectively). For congenital heart defects, the ORs and 95% CIs were all higher, and the magnitude of OR differences ranged from 1.59 to 16.15.

Conclusions

A comprehensive intervention strategy targeting maternal exposure to multiple risk factors is expected to show the strongest results in preventing birth defects.

Describing the Prevalence of Neural Tube Defects Worldwide: A Systematic Literature Review

BACKGROUND

Folate-sensitive neural tube defects (NTDs) are an important, preventable cause of morbidity and mortality worldwide. There is a need to describe the current global burden of NTDs and identify gaps in available NTD data.

METHODS AND FINDINGS

We conducted a systematic review and searched multiple databases for NTD prevalence estimates and abstracted data from peer-reviewed literature, birth defects surveillance registries, and reports published between January 1990 and July 2014 that had greater than 5,000 births and were not solely based on mortality data. We classified countries according to World Health Organization (WHO) regions and World Bank income classifications. The initial search yielded 11,614 results; after systematic review we identified 160 full text manuscripts and reports that met the inclusion criteria. Data came from 75 countries. Coverage by WHO region varied in completeness (i.e., % of countries reporting) as follows: African (17%), Eastern Mediterranean (57%), European (49%), Americas (43%), South-East Asian (36%), and Western Pacific (33%). The reported NTD prevalence ranges and medians for each region were: African (5.2-75.4; 11.7 per 10,000 births), Eastern Mediterranean (2.1-124.1; 21.9 per 10,000 births), European (1.3-35.9; 9.0 per 10,000 births), Americas (3.3-27.9; 11.5 per 10,000 births), South-East Asian (1.9-66.2; 15.8 per 10,000 births), and Western Pacific (0.3-199.4; 6.9 per 10,000 births). The presence of a registry or surveillance system for NTDs increased with country income level: low income (0%), lower-middle income (25%), upper-middle income (70%), and high income (91%).

CONCLUSIONS

Many WHO member states (120/194) did not have any data on NTD prevalence. Where data are collected, prevalence estimates vary widely. These findings highlight the need for greater NTD surveillance efforts, especially in lower-income countries. NTDs are an important public health problem that can be prevented with folic acid supplementation and fortification of staple foods.

Folate status and health: challenges and opportunities

Each year approximately 2400 pregnancies develop folic acid-preventable spina bifida and anencephaly in Europe. Currently, 70% of all affected pregnancies are terminated after prenatal diagnosis. The prevalence of neural tube defects (NTDs) has been significantly lowered in more than 70 countries worldwide by applying fortification with folic acid. Periconceptional supplementation of folic acid also reduces the risk of congenital heart diseases, preterm birth, low birth weight, and health problems associated with child mortality and morbidity. All European governments failed to issue folic acid fortification of centrally processed and widely eaten foods in order to prevent NTDs and other unwanted birth outcomes. The estimated average dietary intake of folate in Germany is 200 μg dietary folate equivalents (DFE)/day. More than half of German women of reproductive age do not consume sufficient dietary folate to achieve optimal serum or red blood cell folate concentrations (>18 or 1000 nmol/L, respectively) necessary to prevent spina bifida and anencephaly. To date, targeted supplementation is recommended in Europe, but this approach failed to reduce the rate of NTDs during the last 10 years. Public health centers for prenatal care and fortification with folic acid in Europe are urgently needed. Only such an action will sufficiently improve folate status, prevent at least 50% of the NTD cases, reduce child mortality and morbidity, and alleviate other health problems associated with low folate such as anemia.