Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention

Demographic variations and temporal trends in prenatal use of multiple micronutrient supplements in Beijing, 2013-2017

OBJECTIVE

To provide updated information about demographic variations and temporal trends in the prenatal use of multiple micronutrient (MMN) supplements in the metropolitan areas of China.

DESIGN

Descriptive analysis of routine prenatal healthcare data between 2013 and 2017.

SETTING

Chaoyang District, Beijing, China.

PARTICIPANTS

A total of 197 346 pregnant women who attended their first prenatal care visit and provided information about MMN supplementation during the periconceptional period.

RESULTS

Of these pregnant women, 60·6 % reported consuming prenatal MMN supplements. In multivariate-adjusted models, there were significant gradients of age, education and parity in prenatal MMN supplementation, with the highest likelihood of MMN use among the oldest, the most highly educated and nulliparous women (Pfor trend < 0·001). Compared with that among unemployed women, prenatal MMN supplementation was more common among the employed, especially those engaged in business (adjusted relative risks (95 % CI): 1·08 (1·06, 1·10)) and management (1·10 (1·08, 1·12)). The proportion of prenatal MMN supplementation was 57·0 % in 2013, which increased to 63·5 % in 2017 (Pfor trend < 0·001). The trends varied by age, education and parity (Pfor heterogeneity < 0·001), whereas no significant difference was observed in trends across subgroups of ethnicity or occupation. The greatest magnitude increase in MMN supplement use occurred in women of age < 25 years (annual percent change: 5·7 %), less than high school education (9·6 %), parity ≥ 2 (6·8 %) or unemployment (6·1 %).

CONCLUSION

Approximately two-thirds of women consumed prenatal MMN supplements during the periconceptional period in the central area of Beijing and the proportion increased over time, indicating a need to evaluate the effectiveness and safety and to develop a guideline for relatively well-nourished women.

Weekly iron-folic acid supplements containing 2.8 mg folic acid are associated with a lower risk of neural tube defects than the current practice of 0.4 mg: a randomised controlled trial in Malaysia

INTRODUCTION

Weekly iron-folic acid (IFA) supplements are recommended for all menstruating women in countries where anaemia prevalence is >20%. Anaemia caused by folate deficiency is low worldwide, and the need to include folic acid is in question. Including folic acid might reduce the risk of a neural tube defect (NTD) should a woman become pregnant. Most weekly supplements contain 0.4 mg folic acid; however, WHO recommends 2.8 mg because it is seven times the daily dose effective in reducing NTDs. There is a reluctance to switch to supplements containing 2.8 mg of folic acid because of a lack of evidence that this dose would prevent NTDs. Our aim was to investigate the effect of two doses of folic acid, compared with placebo, on red blood cell (RBC) folate, a biomarker of NTD risk.

METHODS

We conducted a three-arm double-blind efficacy trial in Malaysia. Non-pregnant women (n=331) were randomised to receive 60 mg iron and either 0, 0.4, or 2.8 mg folic acid once weekly for 16 weeks.

RESULTS

At 16 weeks, women receiving 0.4 mg and 2.8 mg folic acid per week had a higher mean RBC folate than those receiving 0 mg (mean difference (95% CI) 84 (54 to 113) and 355 (316 to 394) nmol/L, respectively). Women receiving 2.8 mg folic acid had a 271 (234 to 309) nmol/L greater mean RBC folate than those receiving 0.4 mg. Moreover, women in the 2.8 mg group were seven times (RR 7.3, 95% CI 3.9 to 13.7; p<0.0001) more likely to achieve an RBC folate >748 nmol/L, a concentration associated with a low risk of NTD, compared with the 0.4 mg group.

CONCLUSION

Weekly IFA supplements containing 2.8 mg folic acid increases RBC folate more than those containing 0.4 mg. Increased availability and access to the 2.8 mg formulation is needed.

TRAIL REGISTRATION NUMBER

This trial is registered with the Australian New Zealand Clinical Trial Registry (ACTRN12619000818134).

Neural Tube Defects and Associated Anomalies before and after Folic Acid Fortification

OBJECTIVE

To examine the prevalence and types of neural tube defects and the types of anomalies co-occurring with neural tube defects in 6 years before fortification of cereal grain flour with folic acid (1992-1998) and 20 years after fortification (1999-2018) in South Carolina, a state with a historically high prevalence of these birth defects.

STUDY DESIGN

The prevalence of neural tube defects was determined by active and passive surveillance methods in South Carolina since 1992. The types of neural tube defects and co-occurring malformations were determined by prenatal ultrasound and post-delivery examination.

RESULTS

In the 6 prefortification years, 363 neural tube defects were identified among 279 163 live births and fetal deaths (1/769), 305 (84%) of which were isolated defects of the calvaria or spine. In the 20 fortification years, there were significant reductions in the prevalence and percentage of isolated defects: 938 neural tube defects were identified among 1 165 134 live births and fetal deaths (1/1242), 696 (74.2%) of which were isolated. The current prevalence of neural tube defects in South Carolina (0.56/1000 live births and fetal deaths) is comparable with that nationwide.

CONCLUSIONS

The continued occurrence of neural tube defects, the majority of which are isolated, after folic acid fortification of cereal grain flours suggests that additional prevention measures are necessary to reduce further the prevalence of these serious defects of the brain and spine.

A 2019 global update on folic acid-preventable spina bifida and anencephaly

BACKGROUND

Mandatory folic acid fortification of staples is a proven intervention to prevent spina bifida and anencephaly, two life-threatening and disabling neural tube defects. We estimated the global proportion of folic acid-preventable spina bifida and anencephaly (FAP SBA) prevented through mandatory folic acid fortification of wheat and/or maize flour in 2019.

METHODS

Using data from the Global Fortification Data Exchange, we identified countries with mandatory fortification policies that required at least 1.0 ppm folic acid be added to wheat and/or maize flour and had information on percentage of industrially milled flour that is fortified. We built FAP SBA prevention models assuming mandatory folic acid fortification at 200 μg/day of folic acid fully protects against FAP SBA and would lower the prevalence neural tube defects to 0.5 per 1,000 live births.

RESULTS

In 2019, 56 countries met our criteria for mandatory folic acid fortification of wheat (n = 56 countries) and/or maize (n = 15 countries) flour and with complete data for our modeling. Overall, our prevention model estimated that 65,380 FAP SBA cases were prevented in 2019 through folic acid fortification of wheat and/or maize flour. We estimated the current global prevention proportion of all preventable FAP SBA cases worldwide to be at 23% of total possible prevention.

CONCLUSION

Global prevention efforts for FAP SBA are slow and have stalled. Mandatory fortification should be urgently implemented in all countries to prevent epidemics of FAP SBA, and to achieve health-related Sustainable Development Goals for year 2030 by reducing child mortality due to preventable FAP SBA.

Periconceptional surveillance for prevention of anaemia and birth defects in Southern India: protocol for a biomarker survey in women of reproductive age

INTRODUCTION

Women of reproductive age (WRA) are a high-risk population for anaemia and micronutrient deficiencies. Evidence supports the role of periconceptional nutrition in the development of adverse pregnancy complications. However, in India, there are limited population-based data to guide evidence-based recommendations and priority setting. The objective of this study is to conduct a population-based biomarker survey of anaemia and vitamin B₁₂ and folate status in WRA as part of a periconceptional surveillance programme in Southern India.

METHODS

WRA (15-40 years) who are not pregnant or lactating and reside within 50 km² of our community research site in Southern India will be screened and invited to participate in the biomarker survey at our research facility at Arogyavaram Medical Centre. After informed consent/assent, structured interviews will be conducted by trained nurse enumerators to collect sociodemographic, dietary, anthropometry, health and reproductive history data. Venous blood samples will be collected at enrolment; whole blood will be analysed for haemoglobin. Plasma, serum and red blood cells (RBCs) will be processed and stored <-80°C until batch analysis. Vitamin B₁₂ concentrations will be measured via chemiluminescence, and RBC and serum folate concentrations will be evaluated using the World Health Organisation (WHO)-recommended microbiological assay at our laboratory in Bangalore. A WHO surveillance system will also be established to determine the baseline prevalence of birth defects in this setting.

ETHICS AND DISSEMINATION

This study has obtained clearance from the Health Ministry Screening Committee of the Indian Council of Medical Research. The study protocol was reviewed and approved by the Institutional Review Board at Cornell University and the Institutional Ethics Committees at Arogyavaram Medical Centre and St. John's Research Institute. Findings from this biomarker survey will establish the burden of anaemia and micronutrient deficiencies in WRA and directly inform a randomised trial for anaemia and birth defects prevention in Southern India. The results of this study will be disseminated at international research conferences and as published articles in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

Clinical trials registration number NCT04048330, NCT03853304 and Clinical Trials Registry of India (CTRI) registration number REF/2019/03/024479.

Neural tube defects in the Free State province from 2012 to 2016. Is there an increase?

Background

Neural tube defects (NTDs) are anomalies of the central nervous system caused by the defective closure of the neural tube during early embryogenesis. A significant decline in the incidence of NTDs after folic acid fortification of food in South Africa was previously shown. Recently, clinical geneticists have voiced concerns that there is a possible resurgence in the number of NTDs.

Objectives

The aim of this study was to determine the incidence of NTDs at a South African Hospital from 2012 to 2016.

Methods

This is a retrospective cross-sectional study where all babies with NTDs born in, or referred to Universitas Hospital were included as study participants. Information was collected for both the mother and the baby from hospital records and data forms.

Results

Seventy-seven cases of NTDs were captured from 2012 to 2016. The incidence of NTDs was 0.34/1000 births in the Free State province, and 1.21/1000 births if only the data for babies born in Universitas Hospital and Pelonomi Hospital were used. Further analysis showed a male: female ratio of 1:1. Open spina bifida was the most common defect at 71.4%.

Conclusion

The incidence of NTDs in the Free State province was low compared to other South African and international studies. The incidence for the metropolitan hospitals is comparable to that of previous studies. This discrepancy is a marker of poor data recording and will impact healthcare planning. A statistically significant increase in NTDs could not be proven.

Prevalence of Spina Bifida among Newborns in Africa: A Systematic Review and Meta-Analysis

Spina bifida is an abnormal closure of the neural tube during the fourth week of development. It is the major cause of fetal loss and considerable disabilities in newborns. The aim of this review is to determine the pooled prevalence of spina bifida among newborns in Africa. PubMed/Medline, Google Scholar, Science Direct, Joanna Briggs Institute (JBI) Library, Cochrane Library, Web of Science, African Journals Online, and Embase databases were systematically searched. Cochran Q test and I 2 test statistics were applied to assess heterogeneity across studies. A random-effect model was applied to calculate the pooled prevalence of spina bifida. Forest plot and Galbraith's plot were used to visualize heterogeneity. Subgroup, sensitivity, meta-regression, and meta-cumulative analyses were performed. All essential data were extracted using a standardized data extraction format, and the JBI quality appraisal checklist was used to assess the quality of studies. Egger's test and Begg's test were used in order to detect the publication bias. In the present systematic review and meta-analysis, 6,587,298 births in twenty-seven studies were included. The pooled birth prevalence of spina bifida in Africa was 0.13% with a range between 0.12% and 0.14%. In Africa, the highest burden of spina bifida was detected in Algeria (0.43%), Ethiopia (0.32%), Tanzania (0.26%), Cameron (0.12%), Egypt (0.10%), and South Africa (0.10%). The lowest burden of spina bifida was detected in Libya (0.006%) and Tunisia (0.009%). The high birth prevalence of spina bifida was detected in Africa. There was a significant variation in the prevalence of spina bifida among study countries in Africa. The authors recommend that special awareness creation with the help of health education intervention should be provided for mothers to focus on prevention in order to reduce the burden of spina bifida.

Genomic profiling of bacterial and fungal communities and their predictive functionality during pulque fermentation by whole-genome shotgun sequencing

Pulque is a culturally important 4,000-year-old traditional Mexican fermented drink. Pulque is produced by adding fresh aguamiel (agave sap) to mature pulque, resulting in a mixture of microbial communities and chemical compositions. We performed shotgun metagenomic sequencing of five stages of pulque fermentation to characterize organismal and functional diversity. We identified 6 genera (Acinetobacter, Lactobacillus, Lactococcus, Leuconostoc, Saccharomyces and Zymomonas) and 10 species (Acinetobacter boissieri, Acinetobacter nectaris, Lactobacillus sanfranciscensis, Lactococcus lactis, Lactococcus piscium, Lactococcus plantarum, Leuconostoc citreum, Leuconostoc gelidum, Zymomonas mobilis and Saccharomyces cerevisiae) that were present ≥ 1% in at least one stage of pulque fermentation. The abundance of genera and species changed during fermentation and was associated with a decrease in sucrose and increases in ethanol and lactic acid, suggesting that resource competition shapes organismal diversity. We also predicted functional profiles, based on organismal gene content, for each fermentation stage and identified an abundance of genes associated with the biosynthesis of folate, an essential B-vitamin. Additionally, we investigated the evolutionary relationships of S. cerevisiae and Z. mobilis, two of the major microbial species found in pulque. For S. cerevisiae, we used a metagenomics assembly approach to identify S. cerevisiae scaffolds from pulque, and performed phylogenetic analysis of these sequences along with a collection of 158 S. cerevisiae strains. This analysis suggests that S. cerevisiae from pulque is most closely related to Asian strains isolated from sake and bioethanol. Lastly, we isolated and sequenced the whole-genomes of three strains of Z. mobilis from pulque and compared their relationship to seven previously sequenced isolates. Our results suggest pulque strains may represent a distinct lineage of Z. mobilis.

Maternal weight as an additional first trimester spina bifida screening marker

OBJECTIVE

To evaluate first trimester maternal weight as a spina bifida screening marker.

METHODS

Case-control study of spina bifida and unaffected pregnancies; cases were from national records and controls from women referred to prenatal screening centers in the Ukraine. The median and inter-quartile range of weight, body mass index (BMI) and the obesity rate (BMI ≥ 30 kg/m²) were compared. Discriminatory power was assessed by logistic regression. Gaussian modeling was used to predict the additional spina bifida detection when weight was included as a screening marker risk in addition to first trimester biparietal diameter (BPD) and serum α-fetoprotein (AFP).

RESULTS

There were 97 cases and 274 controls. The distribution of maternal weight was increased in cases by 3 kg, on average, about 5% (p < .05); BMI was increased about 8% (p < .005). Some 15% of cases were obese compared with 6.9% of controls (p < .02). In logistic regression including BMI and maternal age, 29% cases and 9.8% controls had high risk of spina bifida. Modeling predicted that incorporating weight would increase the detection rate compared with BPD and AFP alone by 3% and BMI would increase it by 4%.

CONCLUSION

Incorporating maternal weight into first trimester spina bifida screening protocols will increase detection.

Effect of folic acid combined with docosahexaenoic acid intervention on mild cognitive impairment in elderly: a randomized double-blind, placebo-controlled trial

PURPOSE

This study aimed to assess the effects of folic acid (FA) combined with a docosahexaenoic acid (DHA) intervention on the cognitive function and inflammatory cytokines in elderly subjects with mild cognitive impairment (MCI).

METHODS

This randomized, double-blind, placebo-controlled trial recruited 240 individuals with MCI in Tianjin, China, and randomly allocated into 4 groups: FA + DHA (FA 800 μg/d + DHA 800 mg/d), FA (FA 800 μg/d), DHA (DHA 800 mg/d), and placebo. Cognitive function, serum folate and homocysteine (Hcy), plasma DHA and inflammatory cytokines levels were measured at baseline and 6 months.

RESULTS

Daily oral FA, DHA and their combined use for 6 months significantly improved the full-scale intelligence quotient (FSIQ) and some subtests of Wechsler Adult Intelligence Scale compared to the placebo. The increases of FSIQ, arithmetic, picture completion scores in the FA group and picture completion, block design scores in the DHA group were significantly less than that in the FA combined DHA group (P < 0.05). Meanwhile, daily oral FA, DHA and their combined use for 6 months significantly decreased plasma inflammatory cytokines compared to the placebo. The changes of interleukin-1β levels in the FA group and interleukin-6 levels in the DHA group were significantly less than that in the FA + DHA group (P < 0.05).

CONCLUSIONS

Daily oral FA, DHA and their combined use for 6 months can significantly improve cognitive function and decrease plasma inflammatory cytokines in MCI individuals. The combination of FA and DHA was more beneficial than each individual nutrient on their own.

Physical Activity, Step Counts, and Grip Strength in the Chinese Children and Families Cohort Study

Objectives: This paper describes the development of a physical activity questionnaire (PAQ) designed for Chinese adolescents and their mothers in urban and rural settings, and reports on results of the PAQ, pedometry, and hand grip dynamometry from the Chinese Children and Families Cohort Study pilot investigation (CFCS). Methods: As part of a pilot investigation to evaluate the feasibility to follow-up and obtain detailed nutrition, dietary, physical activity, and ultraviolet radiation (UVR) data from CFCS participants, data were collected in 2013 for 93 adolescent/mother pairs from a rural (n = 41) and an urban site (n = 52) in two provinces. Respondents were asked to wear a pedometer for seven days (Omron HJ-151), use a Takei Digital Grip Strength Dynamometer on (each hand; three trials; two separate days), and complete a 39 item, eight domain PAQ covering the past year. Self-reported physical activity (PA) was linked to metabolic equivalent of task (MET) scores in kcal/kg/hr and used to calculate METs for different domains of PA and intensity categories. Results: Compliance was high (95%) in this measurement protocol administered by health staff during a series of data collection efforts at home and local clinics or health centers. Step counts were highly variable, averaging between 5000 and 10000 per day with somewhat higher step counts in rural adolescent boys. Maximum grip strength (Kgs) was greater in children (Mean = 36.5, SE = 0.8) than mothers (Mean = 28.8, SE = 0.8) and similar in the urban (Mean = 29.6, SE = 0.6) compared to the rural (Mean = 29.6, SE = 0.5) communities overall. Grip strength, step counts, and measures of time spent in different activities or activity intensities were uncorrelated. Conclusion: Device and question-based measurement of PA and strength were readily accepted in these Chinese urban and rural populations. The PAQ on physical activity in the past year produced some plausible population averages, but individual responses suggested recall challenges. If data about specific activities are required, future studies should explore use of standardized survey questions concerning such fewer specific activities or instruments examining shorter time periods such as one, three, or seven day recalls.

Effectiveness of community-based folate-oriented tertiary interventions on incidence of fetus and birth defects: a protocol for a single-blind cluster randomized controlled trial

BACKGROUND

Birth defects are the main cause of fetal death, infant mortality and morbidity worldwide. However, the etiology of birth defects remains largely unknown. Maternal folate status during periconception plays an important role in organogenesis and folic acid supplement reduces the risk of neural tube defects, congenital heart diseases, and several other birth defects. This trial seeks to evaluate the effectiveness of folate-oriented tertiary interventions during periconception on the incidence of fetus and birth defects.

METHODS

This is a single-blind, two-arm cluster randomized controlled trial in Shanghai, China. Eligible women from 22 clusters are recruited at pre-pregnancy physical examinations clinical settings. Compared to the routine perinatal care group (control arm), folate-oriented tertiary interventions will be provided to the intervention arm. The core interventions consist of assessments of folate status and metabolism, folate intake guidance, and re-evaluation of folate status to ensure red blood cell folate level above 400 ng/ml (906 nmol/L) before pregnancy. Screening and consulting of fetus and birth defects, and treatments of birth defects during pregnancy and afterward will be provided to both arms. The primary outcome is a composite incidence of fetus defects, stillbirth, and neonatal birth defects identified from the confirmation of pregnancy to 28 days after birth. Secondary outcomes include maternal and offspring adverse complications and cost-effectiveness of folate-oriented tertiary interventions. This protocol adheres to the SPIRIT Checklist.

DISCUSSION

To achieve the recommended folate status before or during pregnancy is still a challenge worldwide. This community-based cluster-randomized controlled intervention trial will evaluate the effectiveness of a package of interventions aiming at achieving recommended maternal folate status covering pre- and during pregnancy in reducing fetus and birth defects. Our study has the potential to improve the community-based practice of reducing modifiable risk factors of disease and improving primary prevention of the defects in China. The procedures would formulate the policy on folic acid supplementation during periconception against birth defects in primary care settings.

TRIAL REGISTRATION

Clinical Trial Registry, NCT03725878 . Prospectively registered on 31 October 2018.

[Maternal periconceptional folic acid supplementation and its effects on the prevalence of fetal neural tube defects]

OBJECTIVE

To find out the status of folic acid supplementation among women, to evaluate the prevention effects on neural tube defects (NTDs), and to explore the factors impact on folic acid supplementation compliance.

METHODS

Based on the routine data of 92 121 women in prenatal health care and birth defect surveillance system in Tongzhou District of Beijing from 2013 to 2018, we described the prevalence of periconceptional folic acid supplementation, pre-pregnancy folic acid supplementation and regularly folic acid supplementation (compliance supplementation). Trend χ² tests were used to evaluate the change of folic acid supplementation prevalence. The prevalence difference among the women with folic acid supplementation and without supplementation were tested with Fisher's exact test. Factors asso-ciated with folic acid supplementation compliance rate were analyzed with univariate and multivariate Logistic regression model.

RESULTS

The prevalence of periconceptional folic acid supplementation during the six years was 90.08% and it was increased from 2013 to 2018, but the rate of pre-pregnancy and regular supplementation was only 41.5% and declined from 2013 to 2018, especially 2013 to 2015. The prevalence of NTDs among the fetuses whose mothers took folic acid during periconceptional period was 5.5/10 000, while the prevalence for the fetuses whose mothers did not take folic acid was 19.7/10 000 (P < 0.001), the rates ratio was 27.9% (χ²=23.74, P < 0.001). The difference between the prevalence of NTDs among the fetuses whose mothers took folic acid only and multiple micronutrients was not statistically significant. After controlling the confounding factors, it was found that the compliant folic acid supplementation rates in women, whose household registrations were outside Beijing and whose education levels were junior high school or below, and who were younger than 25 years old, and who were multiparas and who were pre-pregnancy underweight or obese, were lower than those of the corresponding control groups (P < 0.05).

CONCLUSION

The rate of folic acid supplementation among women in Tongzhou District of Beijing was relatively high, but their compliance was poor. Women who did not take folic acid during periconception seriously affected the prevention effect of NTDs. We should focus on women who are younger than 25 years old, lower educated, pre-pregnancy underweight or obese, multiparas and nonlocal household registers, in order to improve the periconceptional folic acid supplementation compliance and improve the effects of NTDs prevention.

Effect of periconceptional folic acid supplementation on the risk of neural tube defects associated with a previous spontaneous abortion or maternal first-trimester fever

STUDY QUESTION

Does maternal periconceptional no folic acid supplementation have an increased risk of neural tube defects (NTDs) associated with previous spontaneous abortion or first-trimester fever?

SUMMARY ANSWER

Maternal periconceptional no folic acid supplementation can increase the risk of NTDs associated with previous spontaneous abortion or first-trimester fever, independent of known confounding factors.

WHAT IS KNOWN ALREADY

Maternal periconceptional folic acid deficiency can increase the risk of NTDs. However, whether an interaction between periconceptional no folic acid supplementation and history of spontaneous abortion or first-trimester fever may have an increased risk of NTDs remains unknown.

STUDY DESIGN, SIZE, DURATION

A population-based case-control study was performed including 104 nuclear families with offspring with NTDs and 100 control families with normal offspring between 1993 and 2002.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We investigated the potential interaction between periconceptional no folic acid use and a maternal history of spontaneous abortion or first-trimester fever in the risk for NTDs. Information on exposure factors was obtained at the onset of pregnancy, and pregnancy outcomes were collected during the first week after delivery or at the time of termination of the pregnancy. A multivariate logistic regression analysis was performed.

MAIN RESULTS AND THE ROLE OF CHANCE

The interaction between periconceptional no folic acid use and a maternal history of spontaneous abortion markedly increased the risk of NTDs (adjusted odds ratio (aOR) 18.68, 95% CI, 4.43-78.76) after adjusting for potential confounding factors. The interaction coefficient was found to be 2.08, higher than 1, indicating that there is a significant interaction between two factors. Mothers who did not take periconceptional folic acid and had first-trimester fever had an increased risk of NTDs (aOR 21.81, 95% CI, 8.81-80.73). However, the interaction coefficient was found to be 0.62, less than 1, indicating that there is no significant interaction between two factors.

LIMITATIONS, REASONS FOR CAUTION

A potential limitation was that the interval between the previous spontaneous abortion and the beginning of the subsequent pregnancy could not be estimated accurately, but was at least 1 year or more.

WIDER IMPLICATIONS OF THE FINDINGS

We emphasize that a previous spontaneous abortion may represent a first occurrence of NTDs rather than be the cause of NTDs. Our findings indicate that mothers with a history of spontaneous abortion are ideal candidates for periconceptional folic acid supplementation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by National Natural Science Foundation of China (41871360) and Danone Nutrition Center for Dietary Nutrition Research and Education Foundation (DIC2015-05). There are no competing interests to declare.

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.

Folic acid supplementation and risk for congenital limb reduction defects in China

BACKGROUND

Folic acid (FA) supplementation prevents neural tube defects, but there are mixed results for its ability to prevent limb reduction defects. We examined whether a preventive effect of FA supplementation exists for congenital limb reduction defects in a large population in China.

METHODS

Data from a large population-based cohort study in China were used to evaluate the effects of FA supplementation on birth defects. All births at 20 complete gestational weeks, including live births, stillbirths and pregnancy terminations, and all structural congenital anomalies, regardless of gestational week, were recorded. A total of 247 831 singleton live births delivered at gestational ages of 20-42 weeks to women from northern and southern China with full information on FA intake were included. Limb reduction defects were classified by subtype and maternal FA supplementation.

RESULTS

The prevalence of limb reduction defects was 2.7 per 10 000 births among women who took FA compared with 9.7 per 10 000 births among those who did not take FA in northern China; the prevalence was 4.5 and 3.8 per 10 000 births, respectively, in southern China. In both unadjusted and adjusted analyses, the estimated relative risk for upper limb reduction defects [odds ratio (OR) = 0.17, 95% confidence interval (CI): 0.04, 0.63] and total limb reduction defects (OR = 0.24, 95% CI: 0.08, 0.70) in northern China, but not for lower limb reduction defects ,was significantly decreased in association with FA supplementation in northern China. There was no association between FA supplementation and either an increased or decreased risk for limb reduction defects in southern China.

CONCLUSIONS

FA supplementation successfully reduces the prevalence of limb reduction defects in northern China, whose population has low folate concentrations.

First-Trimester Maternal Folic Acid Supplementation Reduced Risks of Severe and Most Congenital Heart Diseases in Offspring: A Large Case-Control Study

Background Maternal folic acid supplementation (FAS) reduces the risk of neural tube defects in offspring. However, its effect on congenital heart disease (CHDs), especially on the severe ones remains uncertain. This study aimed to assess the individual and joint effect of first-trimester maternal FAS and multivitamin use on CHDs in offspring. Methods and Results This is a case-control study including 8379 confirmed CHD cases and 6918 controls from 40 healthcare centers of 21 cities in Guangdong Province, China. Adjusted odds ratios (aORs) of FAS and multivitamin use between CHD cases (overall and specific CHD phenotypes) and controls were calculated by controlling for parental confounders. The multiplicative interaction effect of FAS and multivitamin use on CHDs was estimated. A significantly protective association was detected between first-trimester maternal FAS and CHDs among offspring (aOR, 0.69; 95% CI, 0.62-0.76), but not for multivitamin use alone (aOR, 1.42; 95% CI, 0.73-2.78). There was no interaction between FAS and multivitamin use on CHDs (P=0.292). Most CHD phenotypes benefited from FAS (aORs ranged from 0.03-0.85), especially the most severe categories (ie, multiple critical CHDs [aOR, 0.16; 95% CI, 0.12-0.22]) and phenotypes (ie, single ventricle [aOR, 0.03; 95% CI, 0.004-0.21]). Conclusions First-trimester maternal FAS, but not multivitamin use, was substantially associated with lower risk of CHDs, and the association was strongest for the most severe CHD phenotypes. We recommend that women of childbearing age should supplement with folic acid as early as possible, ensuring coverage of the critical window for fetal heart development to prevent CHDs.

Male-to-female ratios among NTDs and women's periconceptional intake of folic acid

BACKGROUND

About a decade ago, a hypothesis was put forward to explain the preponderance of females among neural tube defect (NTD) fetuses. That hypothesis predicts that a woman's higher levels of early gestational intake of methyl groups, such as folic acid, will be associated with lesser male-to-female ratio differences in NTD-affected births, specifically less preponderance of females. We explored this hypothesis in four distinct studies that investigated human NTDs, obtained information on folic acid, and capitalized on timing of folic acid fortification by investigating data that were collected both prior to and after the 1998 initiation of U.S. mandatory folic acid fortification of grains.

METHODS

We analyzed data from four population-based case control studies conducted in California for birth years spanning 1987-2011. Two studies were conducted before folic acid fortification of the U.S. food supply. Each of the four studies included interviews of women who either had NTD-affected pregnancies (cases) or who did not have a pregnancy affected by a birth defect (controls). In each study, information on periconceptional supplement use was elicited. We explored male-to-female ratios and 95% binomial confidence limits in each data set.

RESULTS

Our analyses of two case-control studies performed prior to and two performed post mandatory folate fortification in the United States showed that more NTD-affected fetuses were female in the first two studies. In the studies done before fortification, the frequency of females was even greater among those pregnancies without folic acid supplementation.

CONCLUSION

Our findings suggest folic acid may differentially reduce risk of NTDs among female fetuses.

Red Blood Cell Folate Likely Overestimated in Australian National Survey: Implications for Neural Tube Defect Risk

In 2009, the Australian government mandated the addition of folic acid to bread flour to reduce the incidence of neural tube defects (NTD)-affected pregnancies. In 2011-2012, the Australian Health Measures Survey (AHMS) reported a mean red blood cell (RBC) folate in women of reproductive age (16-44 y) of 1647 nmol/L. Over 99% of women had an RBC folate ≥ 906 nmol/L, a concentration consistent with a very low risk of NTDs if a woman became pregnant. However, RBC folate was measured using an immunoassay, which is not a recommended method due to questionable accuracy. The microbiological assay is the preferred method for RBC folate measurement. To determine whether the immunoassay method may have led to spurious conclusions about the folate status of Australian women, we collected fasting blood samples from 74 healthy non-pregnant, non-lactating women (18-44 y) and measured RBC folate using both the immunoassay and microbiological methods. Mean RBC folate (95% confidence interval) concentration measured with the immunoassay method was 1735 (1666, 1804) nmol/L compared with 942 (887, 1012) nmol/L using the microbiological method. No woman had an RBC folate < 906 nmol/L using the immunoassay method, whereas 46% of women had an RBC folate < 906 nmol/L using the microbiological method. The NTD risk was estimated to be 0.06% using the immunoassay method and 0.14% using the microbiological method. RBC folate using AHMS survey may have underestimated NTD risk in Australian women.

Mouse Models of Neural Tube Defects

During embryonic development, the central nervous system forms as the neural plate and then rolls into a tube in a complex morphogenetic process known as neurulation. Neural tube defects (NTDs) occur when neurulation fails and are among the most common structural birth defects in humans. The frequency of NTDs varies greatly anywhere from 0.5 to 10 in 1000 live births, depending on the genetic background of the population, as well as a variety of environmental factors. The prognosis varies depending on the size and placement of the lesion and ranges from death to severe or moderate disability, and some NTDs are asymptomatic. This chapter reviews how mouse models have contributed to the elucidation of the genetic, molecular, and cellular basis of neural tube closure, as well as to our understanding of the causes and prevention of this devastating birth defect.

Preconception blood pressure and risk of gestational hypertension and preeclampsia: a large cohort study in China

Our objective was to examine whether high blood pressure in the preconception period was associated with gestational hypertension and preeclampsia in Chinese women. Data were obtained from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. We included 45,628 women who were registered before pregnancy in seven counties in South China. Blood pressure was measured during registration by trained health care workers, and other health-related information was recorded prospectively. We used logistic regression to evaluate the associations between preconception blood pressure and the risk of gestational hypertension and preeclampsia, adjusting for potential confounders. The prevalence of hypertension in the preconception study population was 4.57% (2083/45,628). The incidences of gestational hypertension and preeclampsia were 11.95% and 4.08%, respectively, in the hypertension group and 8.60% and 2.28%, respectively, in the nonhypertension group. Compared with the nonhypertension group, the hypertension group showed a significantly increased risk for gestational hypertension [adjusted risk ratio (RR) = 1.40, 95% confidence interval (CI): 1.22-1.60] and preeclampsia [adjusted RR = 1.75, 95% CI: 1.39-2.19]. When participants with normal blood pressure were used as the reference, the adjusted ORs for gestational hypertension were 1.48 (95% CI: 1.37-1.59), 1.70 (95% CI: 1.44-2.01), and 1.29 (95% CI: 1.02-1.64), and for preeclampsia, the adjusted ORs were 1.55 (95% CI: 1.35-1.78), 1.95 (95% CI: 1.46-2.60), and 1.99 (95% CI: 1.39-2.85) for the participants with prehypertension, stage 1 hypertension, and stage 2 hypertension, respectively. Our results support an association between hypertension or higher blood pressure prior to pregnancy and an increased risk of gestational hypertension and preeclampsia.

Maternal folic acid supplementation and more prominent birth weight gain in twin birth compared with singleton birth: a cross-sectional study in northwest China

OBJECTIVE

To investigate the association of folic acid (FA) supplementation with birth weight, the risk of small for gestational age (SGA) and low birth weight (LBW) in singleton and twin pregnancy.

DESIGN

A population-based cross-sectional survey.

SETTING

Twenty counties and ten districts in Shaanxi Province of northwestern China, 2013.

PARTICIPANTS

28 174 pregnant women with their infants, covering 27 818 single live births and 356 twin live births.

RESULTS

The prevalence of FA supplementation in singletons and twins was 63·9 and 66·3 %. The mean birth weight was 3267 (sd 459·1) g, 2525 (sd 534·0) g and 2494 (sd 539·5) g; the prevalence of SGA was 14·3, 51·4 and 53·4 %; the prevalence of LBW was 3·4, 42·4 and 46·6 % among singleton, twin A and twin B, respectively. Compared with non-users, women with FA supplementation were (β 17·3, 95 % CI 6·1, 28·4; β 166·3, 95 % CI 69·1, 263·5) associated with increased birth weight, lower risk of SGA (OR 0·85, 95 % CI 0·80, 0·92; OR 0·45, 95 % CI 0·30, 0·68) and LBW (OR 0·82, 95 % CI 0·71, 0·95; OR 0·50, 95 % CI 0·33, 0·75) in singletons and twins, and more prominent effects in twins. Moreover, there were significant interactions between FA supplementation and plurality on birth weight, SGA and LBW.

CONCLUSIONS

The present study suggests the association of periconceptional 0·4 mg/d FA supplementation with increased birth weight and reduced risk of SGA and LBW in both singletons and twins, and this association may be more prominent in twins.

Associations between prenatal sunshine exposure and birth outcomes in China

This paper is one of the first to examine the associations between prenatal sunshine exposure and birth outcomes, specifically the incidence of low birth weight (LBW) and small for gestational age (SGA), based on a nationally representative birth record dataset in China. During the sample period in the 1990s, migration was limited in rural China, allowing us to address the identification challenges, like residential sorting and avoidance behaviors. We found a nonlinear relationship between the length of sunlight and birth outcomes. In particular, prenatal exposure to increasing sunshine was associated with a reduction in the incidence of LBW and SGA, especially in the second trimester during pregnancy. This finding was consistent with the clinical evidence suggesting positive effects of sunshine on birth outcomes via obtaining vitamin D or relieving maternal stress.

Maternal Cotinine Levels and Red Blood Cell Folate Concentrations in the Periconceptual Period

OBJECTIVES

Studies have examined the association between tobacco use and folate levels in pregnancy, yet few have assessed this relation using objective and accurate measures of both smoking and folate. In this study, we evaluated the association between maternal cotinine levels and periconceptional red blood cell (RBC) folic acid reserves in a cohort of low-income pregnant mothers.

METHODS

Smoking information, based on salivary cotinine, a highly sensitive and specific tobacco smoke exposure biomarker, was used. Furthermore, folate was assessed using RBC folate, an indicator of long-term folate storage. Participants were early to mid-trimester pregnant women who received antenatal care between 2011 and 2015 at the Genesis Clinic of Tampa (Florida). A total of 496 women were enrolled in the study. Associations between smoking status/maternal salivary cotinine concentrations, sociodemographic factors, and folate concentrations were investigated using Tobit regression analyses.

RESULTS

The mean folate level of the participants was 718.3 ± 183.2 ng/mL, and only 2 (0.4%) participants were deficient in folate. We observed no significant difference in folate levels by smoking status. In contrast, salivary cotinine levels were significantly associated with decreased RBC folate concentrations (β -11.43, standard error 5.45, P = 0.032). Prepregnancy maternal body mass index, gestational age, stress, and depression also were associated with folate levels.

CONCLUSIONS

Low RBC folate is associated with perinatal factors, including high maternal cotinine levels, body mass index, stress, and depression. The effect of low folate levels among smokers cannot be overemphasized, considering that tobacco products not only reduce folate levels but also decrease the bioutilization of folate.

Maternal folate levels during pregnancy and children's neuropsychological development at 2 years of age

OBJECTIVE

To explore the relationship between maternal folate levels during pregnancy and children's neuropsychological development at 2 years of age.

METHODS

In the birth cohort MKFOAD, maternal serum folate concentrations at 12-14, 22-26, and 34-36 weeks of gestation were measured, as well as red blood cell (RBC) folate at 12-14 weeks. Neurodevelopment of 2-year-old children was assessed by Gesell Development Scale (GDS), which contained subscales of gross motor, fine motor, language, adaptive behavior, and social behavior. Linear regression models were applied to investigate the association of maternal folate levels with children's developmental quotients (DQs).

RESULTS

One hundred and eighty singleton children participated the GDS assessment, of whom 97 (53.9%) were boys. Median RBC folate concentration was 1002.8 (IQR = 577.6) nmol L^-1 in early pregnancy and median serum folate concentrations were, respectively, 33.9 (IQR = 9.2) nmol L^-1, 26.3 (IQR = 14.3) nmol L^-1, and 26.7 (IQR = 18.9) nmol L^-1. Maternal serum folate concentration in late pregnancy was significantly associated with children's language development, where language DQ increases by 3.1 (95% CI 0.6, 5.5) for every 10 nmol L^-1 increment of serum folate concentration. And maternal serum folate in early pregnancy was significantly associated with children's fine motor development, with 2.0 (95% CI 0.1, 4.0) DQ decrease for 10 nmol L^-1 increase of serum folate.

CONCLUSIONS

Maternal serum folate in late pregnancy was significantly associated with children's language development at age 2, which supports the importance of remaining folic acid supplementation across the entire gestation. However, maternal serum folate in early pregnancy was also inversely associated with children's fine motor development.

External validation of a new classification of spinal lipomas based on embryonic stage

OBJECTIVE

Contention exists regarding appropriate classification and management of spinal lipomas (SLs). Given the heterogeneity of SLs, omissions and overlap between surgically incomparable groups exist in conventional classification systems. The new classification of spinal lipoma (NCSL) recently proposed by Morota et al. delineates morphology by embryological pathogenesis and the resultant operative difficulty. Here, the authors aimed to validate the NCSL by applying it to patients who had been operated on at their institution.

METHODS

All children who had undergone resection for SL between 2014 and 2018 were included in this analysis. MRI studies were independently reviewed and classified by three adjudicators. Baseline characteristics, inter-adjudicator agreement, coexisting anomalies and/or malformations, and postoperative outcomes and complications were analyzed.

RESULTS

Thirty-six patients underwent surgical untethering for SL: NCSL type 1 in 5 patients (14%), type 2 in 14 patients (39%), type 3 in 4 patients (11%), and type 4 in 13 patients (36%). All classification was agreed on first assignment by the adjudicators. Radical or near-radical resection, which was attempted in all patients, was always possible in those with type 1 and 4 SL, but never in those with type 2 and 3 SL. Neurological stabilization and/or improvement were observed in all patients at the last follow-up.

CONCLUSIONS

The NCSL was found to be a logical and reproducible system to apply in this SL population. All cases were successfully classified with a high degree of inter-assessor agreement. Widespread establishment of a commonly adopted and clinically useful classification system will enable clinicians to improve patient selection as well as discussion with patient representatives during the decision-making process.

Potential effects of alginate-pectin biocomposite on the release of folic acid and their physicochemical characteristics

Potential effects of folates on the treatment of several human diseases like cognitive function, neural tube defects, coronary heart disease and certain kinds of cancers have been discovered. However, the stability of folic acid against adverse conditions is a great concern. The present study investigates various alginate (A)-pectin (P) gastrointestinal-resistant hydrogel to immobilize folic acid. This involves evaluating different compositions of alginate-pectin to achieve higher encapsulation efficiency and stability during simulated gastric (SG) and simulated intestinal (SI) conditions. Coated alginate hydrogels with pectin resulted significant (p < 0.05) better protection of folic acid compared to non-coated alginate hydrogel when exposed to SG condition and when exposed to SI condition, sustained release behavior obtained with the ratio of A70-P30. The structural and physicochemical properties of blended A-P hydrogel were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffractometer, indicating the presence of folic acid into the matrix and signified no covalent reaction between components. Therefore, this adequate composition of alginate-pectin showed to be a potential carrier for folic acid stability.

Effects of Preconception Care and Periconception Interventions on Maternal Nutritional Status and Birth Outcomes in Low- and Middle-Income Countries: A Systematic Review

Pregnancy in adolescence and malnutrition are common challenges in low- and middle-income countries (LMICs), and are associated with many complications and comorbidities. The preconception period is an ideal period for intervention as a preventative tactic for teenage pregnancy, and to increase micronutrient supplementation prior to conception. Over twenty databases and websites were searched and 45 randomized controlled trials (RCTs) or quasi-experimental interventions with intent to delay the age at first pregnancy (n = 26), to optimize inter-pregnancy intervals (n = 4), and supplementation of folic acid (n = 5) or a combination of iron and folic acid (n = 10) during the periconception period were included. The review found that educational interventions to delay the age at first pregnancy and optimizing inter-pregnancy intervals significantly improved the uptake of contraception use (RR = 1.71, 95% CI = 1.42-2.05; two studies, n = 911; I2 = 0%) and (RR = 2.25, 95% CI = 1.29-3.93; one study, n = 338), respectively. For periconceptional folic acid supplementation, the incidence of neural tube defects were reduced (RR = 0.53; 95% CI = 0.41-0.77; two studies, n = 248,056; I2 = 0%), and iron-folic acid supplementation improved the rates of anemia (RR = 0.66, 95% CI = 0.53-0.81; six studies; n = 3430, I2 = 88%), particularly when supplemented weekly and in a school setting. Notwithstanding the findings, more robust RCTs are required from LMICs to further support the evidence.

Effect of once weekly folic acid supplementation on erythrocyte folate concentrations in women to determine potential to prevent neural tube defects: a randomised controlled dose-finding trial in Malaysia

INTRODUCTION

Folic acid (0.4 mg) taken prior to and during early pregnancy reduces the risk of neural tube defects (NTDs). Because these birth defects occur early in pregnancy, before women may know they are pregnant, many countries have mandated the addition of folic acid to food staples. In countries where fortification is not possible, and weekly iron folic acid programmes exist to reduce anaemia, the WHO recommends that 2.8 mg (7×0.4 mg) folic acid be given instead of the current weekly practice of 0.4 mg. Currently, there is a lack of evidence to support if the 2.8 mg folic acid per week dose is sufficient to raise erythrocyte folate concentrations to a level associated with a reduced risk of a NTD-affected pregnancy. We aim to conduct a three-arm randomised controlled trial to determine the effect of weekly folic acid with iron on erythrocyte folate, a biomarker of NTD risk.

METHODS AND ANALYSIS

We will recruit non-pregnant women (n=300; 18-45 years) from Selangor, Malaysia. Women will be randomised to receive either 2.8, 0.4 or 0.0 (placebo) mg folic acid with 60 mg iron weekly for 16 weeks, followed by a 4-week washout period. The primary outcome will be erythrocyte folate concentration at 16 weeks and the mean concentration will be compared between randomised treatment groups (intention-to-treat) using a linear regression model adjusting for the baseline measure.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the University of British Columbia (H18-00768) and Universiti Putra Malaysia (JKEUPM-2018-255). The results of this trial will be presented at scientific conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

ACTRN12619000818134 and NMRR-19-119-45736.

Maternal hypertension, preeclampsia, and risk of neonatal respiratory disorders in a large-prospective cohort study

BACKGROUND

Possible impact of maternal hypertension and preeclampsia on neonatal respiratory disorders was unknown. We investigated the association of maternal hypertension and preeclampsia with neonatal respiratory disorders in preterm and full-term newborns.

METHOD

In this study, we used a large Chinese population-based study which includes 185,687 singleton livebirths with gestational weeks between 28 and 42 weeks. The "exposure" was maternal hypertension and preeclampsia. The outcome was neonatal respiratory disorders including neonatal respiratory distress syndrome (NRDS), pneumonia and low Apgar scores. Logistic regression was used to examine the association between the maternal hypertensive disorders and the risk for neonatal respiratory disorders. We further evaluated the association in preterm and full-term infants.

RESULTS

As a result, the incidence of neonatal RDS, pneumonia, and low Apgar score in hypertensive group was higher than that in normotensive group. Preeclampsia was associated with RDS [(adjusted relative risk (aRR): 1.85, 95% confidence interval (CI): 1.22-3.05)]. Both maternal hypertension and preeclampsia increased risks for neonatal pneumonia (aRR: 1.79, 95%CI: 1.48-2.17; aRR: 1.81, 95%CI: 1.36-2.40, respectively), for low Apgar score at 1 min (aRR: 1.20, 95%CI: 1.13-1.27; aRR: 1.53, 95%CI: 1.41-1.67, respectively), and for low Apgar score at 5 min (aRR: 1.30, 95%CI: 1.17-1.45; aRR: 1.70, 95%CI: 1.46-1.99, respectively). The risk for neonatal respiratory disorders increased with severity of maternal hypertension. The observed associations were present in both full-term and preterm birth.

CONCLUSION

Maternal hypertension and preeclampsia are risk factors for neonatal respiratory disorders in full-term and preterm newborns.

Periconceptional folic acid supplementation and risk of parent-reported asthma in children at 4-6 years of age

BACKGROUND

Folic acid supplementation is universally recommended for women of child-bearing age to prevent fetal neural tube defects (NTDs). Concerns have arisen over the potential risk for childhood allergy and asthma due to folic acid supplementation. We examined whether periconceptional supplementation with low-dose folic acid only was associated with an increased risk for allergy symptoms or asthma in offspring at 4-6 years of age.

METHODS

Out of 247 831 participating women enrolled in 1993-1996, 9090 were randomly selected and their children were followed up in 2000-2001. Information on mothers' demographic characteristics, folic acid supplementation and allergic diseases among children was collected. We used logistic regression to evaluate the association between folic acid intake and risk for allergic disease while adjusting for potential confounding factors.

RESULTS

The rate of allergy symptoms was 1.54% among children whose mothers had taken folic acid compared with 2.04% among those whose mothers had not taken folic acid, and the rate of asthma was 0.92% and 0.88%, respectively. Maternal folic acid supplementation was not associated with risk for allergy symptoms or asthma, with odds ratios (95% CI) of 0.80 (0.58-1.11) and 1.04 (0.67-1.61), respectively. No differences in the occurrence of allergy symptoms or asthma were observed when data were analysed by timing of supplementation or compliance with folic acid supplementation.

CONCLUSIONS

Supplementation with low-dose folic acid only during the periconceptional period did not increase risk for allergy symptoms or asthma in children at 4-6 years of age in a population without staple fortification with folic acid.

Cannabis Consumption Patterns Explain the East-West Gradient in Canadian Neural Tube Defect Incidence: An Ecological Study

While a known link between prenatal cannabis exposure and anencephaly exists, the relationship of prenatal cannabis exposure with neural tube defects (NTDs) generally has not been defined. Published data from Canada Health and Statistics Canada were used to assess this relationship. Both cannabis use and NTDs were shown to follow an east-west and north-south gradient. Last year cannabis consumption was significantly associated (P < .0001; cannabis use-time interaction P < .0001). These results were confirmed when estimates of termination for anomaly were used. Canada Health population data allowed the calculation of an NTD odds ratio) of 1.27 (95% confidence interval = 1.19-1.37; P < 10-11) for high-risk provinces versus the remainder with an attributable fraction in exposed populations of 16.52% (95% confidence interval = 12.22-20.62). Data show a robust positive statistical association between cannabis consumption as both a qualitative and quantitative variable and NTDs on a background of declining NTD incidence. In the context of multiple mechanistic pathways these strong statistical findings implicate causal mechanisms.

Low folate concentration impacts mismatch repair deficiency in neural tube defects

Aim: To know the cause of sequence variants in neural tube defect (NTD). Materials & methods: We sequenced genes implicated in neural tube closure (NTC) in a Chinese cohort and elucidated the molecular mechanism-driving mutations. Results: In NTD cases, an increase in specific variants was identified, potentially deleterious rare variants harbored in H3K36me3 occupancy regions that recruits mismatch repair (MMR) machinery. Lower folate concentrations in local brain tissues were also observed. In neuroectoderm cells, folic acid insufficiency attenuated association of Msh6 to H3K36me3, and reduced bindings to NTC genes. Rare variants in human NTDs were featured by MMR deficiency and more severe microsatellite instability. Conclusion: Our work suggests a mechanistic link between folate insufficiency and MMR deficiency that correlates with an increase of rare variants in NTC genes.

Cellular mechanisms underlying Pax3-related neural tube defects and their prevention by folic acid

Neural tube defects (NTDs), including spina bifida and anencephaly, are among the most common birth defects worldwide, but their underlying genetic and cellular causes are not well understood. Some NTDs are preventable by supplemental folic acid. However, despite widespread use of folic acid supplements and implementation of food fortification in many countries, the protective mechanism is unclear. Pax3 mutant (splotch; Sp2H ) mice provide a model in which NTDs are preventable by folic acid and exacerbated by maternal folate deficiency. Here, we found that cell proliferation was diminished in the dorsal neuroepithelium of mutant embryos, corresponding to the region of abolished Pax3 function. This was accompanied by premature neuronal differentiation in the prospective midbrain. Contrary to previous reports, we did not find evidence that increased apoptosis could underlie failed neural tube closure in Pax3 mutant embryos, nor that inhibition of apoptosis could prevent NTDs. These findings suggest that Pax3 functions to maintain the neuroepithelium in a proliferative, undifferentiated state, allowing neurulation to proceed. NTDs in Pax3 mutants were not associated with abnormal abundance of specific folates and were not prevented by formate, a one-carbon donor to folate metabolism. Supplemental folic acid restored proliferation in the cranial neuroepithelium. This effect was mediated by enhanced progression of the cell cycle from S to G2 phase, specifically in the Pax3 mutant dorsal neuroepithelium. We propose that the cell-cycle-promoting effect of folic acid compensates for the loss of Pax3 and thereby prevents cranial NTDs.

National population-based estimates for major birth defects, 2010-2014

BACKGROUND

Using the National Birth Defects Prevention Network (NBDPN) annual data report, U.S. national prevalence estimates for major birth defects are developed based on birth cohort 2010-2014.

METHODS

Data from 39 U.S. population-based birth defects surveillance programs (16 active case-finding, 10 passive case-finding with case confirmation, and 13 passive without case confirmation) were used to calculate pooled prevalence estimates for major defects by case-finding approach. Fourteen active case-finding programs including at least live birth and stillbirth pregnancy outcomes monitoring approximately one million births annually were used to develop national prevalence estimates, adjusted for maternal race/ethnicity (for all conditions examined) and maternal age (trisomies and gastroschisis). These calculations used a similar methodology to the previous estimates to examine changes over time.

RESULTS

The adjusted national birth prevalence estimates per 10,000 live births ranged from 0.62 for interrupted aortic arch to 16.87 for clubfoot, and 19.93 for the 12 critical congenital heart defects combined. While the birth prevalence of most birth defects studied remained relatively stable over 15 years, an increasing prevalence was observed for gastroschisis and Down syndrome. Additionally, the prevalence for atrioventricular septal defect, tetralogy of Fallot, omphalocele, and trisomy 18 increased in this period compared to the previous periods. Active case-finding programs generally had higher prevalence rates for most defects examined, most notably for anencephaly, anophthalmia/microphthalmia, trisomy 13, and trisomy 18.

CONCLUSION

National estimates of birth defects prevalence provide data for monitoring trends and understanding the impact of these conditions. Increasing prevalence rates observed for selected conditions warrant further examination.

The antagonism of folate receptor by dolutegravir: developmental toxicity reduction by supplemental folic acid

OBJECTIVE

Maternal folate (vitamin B9) status is the largest known modifier of neural tube defect risk, so we evaluated folate-related mechanisms of action for dolutegravir (DTG) developmental toxicity.

DESIGN

Folate receptor 1 (FOLR1) was examined as a target for DTG developmental toxicity using protein and cellular interaction studies and an animal model.

METHODS

FOLR1 competitive binding studies were used to test DTG for FOLR1 antagonism. Human placenta cell line studies were used to test interactions with DTG, folate, and cations. Zebrafish were selected as an animal model to examine DTG-induced developmental toxicity and rescue strategies.

RESULTS

FOLR1 binding studies indicate DTG is a noncompetitive FOLR1 antagonist at therapeutic concentrations. In-vitro testing indicates calcium (2 mmol/l) increases FOLR1-folate interactions and alters DTG-FOLR1-folate interactions and cytotoxicity. DTG does not inhibit downstream folate metabolism by dihydrofolate reductase. Early embryonic exposure to DTG is developmentally toxic in zebrafish, and supplemental folic acid can mitigate DTG developmental toxicity.

CONCLUSION

Folates and FOLR1 are established modifiers of risk for neural tube defects, and binding data indicates DTG is a partial antagonist of FOLR1. Supplemental folate can ameliorate increased developmental toxicity due to DTG in zebrafish. The results from these studies are expected to inform and guide future animal models and clinical studies of DTG-based antiretroviral therapy in women of childbearing age.

Impact of gestational hypertension and preeclampsia on fetal gender: A large prospective cohort study in China

BACKGROUND

Recent studies suggested an association between fetal sex preponderance and hypertensive disorders during pregnancy, but the conclusions were inconsistent. Our objective was to investigate whether the occurrence of gestational hypertensive disorders would affect the possibility of delivering boys.

METHODS

Data were obtained from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. We included participants who were registered in 2 southern Chinese provinces, and whose information of blood pressure and sex delivery were recorded in detailed. Blood pressure was measured during pregnancy by trained health care workers and other health-related information was recorded prospectively. We used log-binomial regression to evaluate the association between gestational hypertension or preeclampsia and the chance of male delivery.

RESULTS

Among 205,605 singleton pregnancy women, the overall incidences of gestational hypertension and preeclampsia were 9.5% and 2.4%, respectively. The prevalence of male delivery was 51.1% and 50.2% in the groups of gestational hypertension and preeclampsia, while in the normotension group was 52.0%. After adjustment for the effects of the main potential confounders, women with gestational hypertension and preeclampsia both showed significantly decreased probability of giving birth to a boy. The adjusted risk ratios (RRs) were 0.98 (95% confidence interval (CI): 0.97-0.99) and 0.96 (95% CI: 0.94-0.99), respectively.

CONCLUSIONS

Our results support a slight but significant association between gestational hypertension or preeclampsia and decreased likelihood of male delivery.

Reducing inequities in preventable neural tube defects: the critical and underutilized role of neurosurgical advocacy for folate fortification

Neural tube defects (NTDs) are one of the greatest causes of childhood mortality and disability-adjusted life years worldwide. Global prevalence at birth is approximately 18.6 per 10,000 live births, with more than 300,000 infants with NTDs born every year. Substantial strides have been made in understanding the genetics, pathophysiology, and surgical treatment of NTDs, yet the natural history remains one of high morbidity and profound impairment of quality of life. Direct and indirect costs of care are enormous, which ensures profound inequities and disparities in the burden of disease in countries of low and moderate resources. All indices of disease burden are higher for NTDs in developing countries. The great tragedy is that the majority of NTDs can be prevented with folate fortification of commercially produced food. Unequivocal evidence of the effectiveness of folate to reduce the incidence of NTDs has existed for more than 25 years. Yet, the most comprehensive surveys of effectiveness of implementation strategies show that more than 100 countries fail to fortify, and consequently only 13% of folate-preventable spina bifida is actually prevented. Neurosurgeons harbor a disproportionate, central, and fundamental role in the management of NTDs and enjoy high standing in society. No organized group in medicine can speak as authoritatively or convincingly. As a result, neurosurgeons and organized neurosurgery harbor disproportionate potential to advocate for more comprehensive folate fortification, and thereby prevent the most common and severe birth defect to impact the human nervous system. Assertive, proactive, informed advocacy for folate fortification should be a central and integral part of the neurosurgical approach to NTDs. Only by making the prevention of dysraphism a priority can we best address the inequities often observed worldwide.

Inadequate Folic Acid Intake Among Women Taking Antiepileptic Drugs During Pregnancy in Japan: A Cross-Sectional Study

This study aimed to assess characteristics of pregnant women taking antiepileptic drugs with inadequate folic acid intake. This cross-sectional study examined pregnant women taking antiepileptic drugs who were registered in the Japanese Drug Information Institute in Pregnancy (JDIIP) database between October 2005 and December 2016. Participants were classified into two groups according to when they started folic acid supplementation (before pregnancy: 'adequate', after pregnancy or never: 'inadequate'). Logistic regression analysis was performed to investigate factors associated with inadequate folic acid intake. Of 12,794 registrants, 468 pregnant women were taking antiepileptics during the first trimester. Of these, we analysed data from 456 women who had no missing data. As a result, inadequate folic acid intake was noted among 83.3% of them, suggesting that the current level of folic acid intake is insufficient overall. Younger age, smoking, alcohol drinking, multiparity, unplanned pregnancy, and being prescribed AEDs by paediatric or psychiatric departments were independent factors associated with inadequate folic acid intake. As planned pregnancy was the strongest factor, healthcare professionals should ensure that childbearing women taking antiepileptics are informed of the importance of planned pregnancy. In addition, healthcare professionals must gain a better understanding of folic acid intake, as the prevalence of adequate intake differed according to which departments prescribed antiepileptic drugs.

Whole Genome Analyses of Chinese Population and De Novo Assembly of A Northern Han Genome

To unravel the genetic mechanisms of disease and physiological traits, it requires comprehensive sequencing analysis of large sample size in Chinese populations. Here, we report the primary results of the Chinese Academy of Sciences Precision Medicine Initiative (CASPMI) project launched by the Chinese Academy of Sciences, including the de novo assembly of a northern Han reference genome (NH1.0) and whole genome analyses of 597 healthy people coming from most areas in China. Given the two existing reference genomes for Han Chinese (YH and HX1) were both from the south, we constructed NH1.0, a new reference genome from a northern individual, by combining the sequencing strategies of PacBio, 10× Genomics, and Bionano mapping. Using this integrated approach, we obtained an N50 scaffold size of 46.63 Mb for the NH1.0 genome and performed a comparative genome analysis of NH1.0 with YH and HX1. In order to generate a genomic variation map of Chinese populations, we performed the whole-genome sequencing of 597 participants and identified 24.85 million (M) single nucleotide variants (SNVs), 3.85 M small indels, and 106,382 structural variations. In the association analysis with collected phenotypes, we found that the T allele of rs1549293 in KAT8 significantly correlated with the waist circumference in northern Han males. Moreover, significant genetic diversity in MTHFR, TCN2, FADS1, and FADS2, which associate with circulating folate, vitamin B12, or lipid metabolism, was observed between northerners and southerners. Especially, for the homocysteine-increasing allele of rs1801133 (MTHFR 677T), we hypothesize that there exists a "comfort" zone for a high frequency of 677T between latitudes of 35-45 degree North. Taken together, our results provide a high-quality northern Han reference genome and novel population-specific data sets of genetic variants for use in the personalized and precision medicine.

Effect of celiac disease on maternal and neonatal outcomes of pregnancy

PURPOSE

Celiac disease (CD) is a permanent immune reaction to gluten that is likely related to genetic factors. Some studies have linked CD to adverse maternal and/or neonatal outcomes but the data has been contradictory. The purpose of this study was to evaluate the effect of CD on pregnancy outcomes.

MATERIALS AND METHODS

We used data from the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (NIS) of the USA to conduct a population-based retrospective cohort study of women who delivered between 1999 and 2014. Pregnancies were categorized as having CD if corresponding ICD-9 code was present. Unconditional logistic regression models were used to estimate the adjusted effect on maternal and fetal outcomes.

RESULTS

There were 14,513,587 births during the study period of which 2755 were to women with CD, for an overall prevalence of 1.9 cases/10,000 births and with rates increasing over the study period. Women with CD tended to be older, Caucasian and to have pre-existing comorbidities, especially other autoimmune diseases. Women with CD were at greater risk of hyperemesis gravidarum, 4.52 (3.68-5.57), Clostridium difficile colitis, 7.56 (3.14-18.20), and venous thromboembolic events, 2.93 (2.07-4.15), as well as, hospital stays >3 d, 2.06 (1.75-2.43). Infants of women with CD were more likely to be growth restricted, 1.80 (1.46-2.21) and have congenital malformations, 3.51 (2.68-4.58).

CONCLUSIONS

CD in pregnancy is associated with increased adverse maternal and newborn complications. These pregnancies should be considered high risk and may benefit from increased surveillance.

Is Depression Related to Low Folate Levels in People with Epilepsy? An Observational Study and Meta-analysis

Background:

Both depression and low serum levels of folate are common in people with epilepsy (PWE), the latter especially in patients on hepatic enzyme-inducing antiepileptic drugs (AEDs). We did a cross-sectional study and a meta-analysis to assess if lower folate levels have any relation with depression in PWE.

Materials and Methods:

Two hundred and one PWE were recruited and assessed for depression using the Inventory of Depressive Symptomatology-Self-Rated (IDS-SR) and Inventory of Depressive Symptomatology-Clinician Rated; serum folate levels were measured in them at the same time. Literature search was carried out and studies with data on depression as well as folate levels in PWE were included. Statistical analysis to determine frequency of depression, low folate levels, and relation between them among our cases and the pooled data from the included studies was done.

Results:

Depression was observed in 65.68% and low serum folate (<4 ng/ml) in 48.75% of PWE (over 80% on older AEDs); there was no statistically significant correlation between them. However, on analyzing the pooled data of six studies including the present, the Fisher's z-transformed correlation coefficient was −0.1690 (95% confidence interval [−0.3175, −0.0124], P = 0.0464).

Conclusions:

Depression and low folate levels are common in PWE. Low folate levels have a mild but significant negative correlation with depression in this population, and folate supplementation would be advisable for those on the older AEDs.

Lack of historical evidence to support folic acid exacerbation of the neuropathy caused by vitamin B12 deficiency

In 1998 a Tolerable Upper Intake Level (UL) for folic acid was established based on case reports from the 1940s suggesting that high-dosage folic acid intake, used to treat patients with pernicious anemia, had the potential to precipitate or speed-up the development of neurological problems. This UL has been employed in the decision-making process used by more than 80 countries to establish programs to fortify staple foods with folic acid to prevent neural tube birth defects. Some have claimed that this UL is flawed and has become an obstacle to the wider adoption of neural tube defect prevention programs and have called for re-evaluation of the scientific validity of this UL. Case reports cannot establish causality, but they can reveal patterns in the timing of the onset and treatment of patients with pernicious anemia. These patterns can be compared with secular trends of usual medical practice for the treatment of pernicious anemia and with the changes in usage of folic acid preparations, including recommended therapeutic dosage and precautions for its usage surrounding the synthesis of folic acid in 1945 and vitamin B12 in 1948. Folic acid package inserts, early editions of hematology textbooks, and international expert reports provide valuable historical information. The recommended therapeutic daily dosage for folic acid of 5-20 mg was unchanged from 1946 through to 1971. The likely cause of the neurological problems encountered is the development of vitamin B12 neuropathy when pernicious anemia was treated with high-dosage folic acid before vitamin B12 was widely available in the early 1950s. Thus, the historical record does not provide compelling evidence that folic acid can potentially cause neurologic complications among those with low vitamin B12 status and lends support for reconsidering the basis for the UL of folic acid.

Gestational hypertension and pre-eclampsia and risk of spontaneous premature rupture of membranes: A population-based cohort study

OBJECTIVE

To examine whether gestational hypertension and pre-eclampsia are associated with spontaneous premature rupture of membranes (PROM).

METHODS

A retrospective, population-based cohort study was conducted in Hebei, Zhejiang, and Jiangsu provinces in China from 1993 to 1995. After excluding women with missing data of exposure and outcome, history of chronic hypertension, multiple births, and babies with major birth defects and ambiguous sex, this study comprised 199 231 singleton live births. Logistic regression was used to evaluate the association, adjusting for potential confounders.

RESULTS

The incidence of PROM was 17.7% and 8.9% in women with gestational hypertension and pre-eclampsia, respectively, and 5.9% for the normotensive group. Compared with normotension, gestational hypertension was associated with an increase in the odds of PROM of 4.21 times (95% confidence interval [CI] 3.77-4.70), while pre-eclampsia had an increase of 2.27 times (95% CI 1.78-2.88). Additionally, women with hypertensive disorders of pregnancy had higher risks for term PROM (adjusted risk ratio [RR] 3.83, 95% CI 3.43-4.27) than preterm PROM (adjusted RR 3.10, 95% CI 2.18-4.41). Consistent results of the association were also observed in the sensitivity analyses.

CONCLUSION

Gestational hypertension and pre-eclampsia were associated with an increased risk for PROM. Increased odds were observed for term PROM compared with preterm PROM.