National Neural Tube Defects Prevention Program in China

Nutritional Status of Selenium and Its Association with Diet and Indoor Air Pollution among Pregnant Women in a Rural Area of Northern China

The nutritional status of selenium (Se) in pregnant women in rural areas of northern China and its association with diet and indoor air pollution are rarely reported. We recruited 273 pregnant women in early or middle term in Shanxi and Hebei province and detected their fasting blood selenium. Demographic characteristics, food habits, and indoor air pollution exposure were collected with a questionnaire. Multivariate logistic regression models were used to estimate the adjusted odds ratios (AORs) and their 95% confidence intervals for the factors and relatively low blood levels of Se (below the lower quartile). The median (interquartile range [IQR]) blood concentration of Se was 117.35 (103.90, 129.23) μg/L. The rate of Se deficiency was 4.8%, and the rate of overnutrition was 23.8%. The AORs for the risk for relatively low blood levels of Se were 2.26 (1.15, 4.44) for consuming less beef and pork/mutton; 0.39 (0.19, 0.80) for a lower frequency of vinegar consumption; and 1.41 (0.76, 2.60) and 1.18 (0.59, 2.36) for passive smoking and indoor coal pollution, respectively. In conclusion, the nutritional status of Se in pregnant women in a rural area of northern China was acceptable; diet was the main determinant; no conclusive association was found between indoor air pollution and Se nutritional status.

Assessing the Nutrient Adequacy in China's Food Supply from 1965 to 2018

Nutritional intake has important impacts on human health. A sufficient supply of nutrients is required to ensure high-level nutrition in a population. Assessment of nutrient supply adequacy can help to develop evidence-based policies and thereby promote public health. This study estimates the supply adequacy of nutrients in China's food system from 1965 to 2018 at the national level, aiming to reveal whether the supply of nutrients meets the demand. The results show that the nutrient supply in China's food system has experienced a sharp increase in the past five decades, and the deficiency in nutrient supply has been greatly mitigated. Although most nutrients such as potassium are already sufficiently supplied in China's current food system, some nutrients, especially calcium and zinc, still need a further enlarged supply to improve the nutrition condition of the Chinese population. Besides encouraging a healthy diet, supply-side regulation, e.g., fortification and enrichment, is also needed to improve nutrient availability. This study helps people better understand the development and current situation of nutrient adequacy in China's food supply, thereby providing information and implications for policymakers.

Folic Acid Status and Associated Factors for Pregnant Chinese Women - China, 2015

What is already known on this topic?

Low folate status in pregnancy has been associated with multiple adverse pregnancy outcomes, including neural tube defects, congenital heart defects, fetal growth restriction, low birth weight, and preterm delivery. Low folate status is common in China, especially in northern areas.

What is added by this report?

Folate status remains suboptimal among pregnant Chinese women in 2015. Folate concentration was in the widespread in rural area (9.88ng/mL) and especially in the northern of China (9.10ng/mL). Pregnant women in the last trimester had the lowest folic acid concentration (9.18 ng/mL). Taking folic acid supplements every day would achieve adequate serum folate concentrations (10.87 ng/mL vs. 10.11 ng/mL vs. 9.38 ng/mL, P<0.001).

What are the implications for public health practice?

Folic acid interventions should be strengthened, especially for pregnant women in rural areas and in northern China, those with junior school or below education, those pregnant during spring and winter, or those with late pregnancy.

Folic acid supplementation acts as a chemopreventive factor in tumorigenesis of hepatocellular carcinoma by inducing H3K9Me2-dependent transcriptional repression of LCN2

The effects and mechanisms of folic acid (FA) as a chemopreventive agent for tumorigenesis of hepatocellular carcinoma (HCC) remain unclear. In this study, the QSG-7701, a human normal liver cell line, was cultured in different FA levels (High, Normal or No) for 6 months. Then, the biological characteristics, the expression of main stem cell-like genes or epithelial-mesenchymal transition (EMT) related genes and the tumorigenicity in vivo of cells cultured in different treatment groups were detected. Our results showed that No FA improved the malignant transformation of cells but High FA depressed the malignant transformation. Meanwhile, cells in different treatment groups were mapped by transcriptome sequencing. Then the relativity of increased LCN2 and decreased FA level was identified and confirmed in vitro and vivo. We also revealed that intracellular control of LCN2 would recover the effects of FA on cell proliferation, cell cycle and tumor formation in vitro and vivo. Finally, our studies displayed that increased FA level induced the down-regulation of LCN2 not by DNA hypermethylation of LCN2 promoter but by promoting the level of histone H3 lysine 9 di-methylation (H3K9Me2) in LCN2 promoter. In conclusion, our studies disclosed the chemopreventive effect of FA supplementation on hepatocarcinogenesis, which partial attributed to the inhibition of LCN2 by regulating histone methylation in promoter. Our results provide a potential mechanism of the chemoprevention of FA supplementation on tumorigenesis of HCC and may be helpful in developing treatment target against HCC.

Effects of parental level of income and visual presentation of spina bifida occulta in decision making process

Background:

Parents are active participants in the referral process of children with non-life-threatening surgical pathologies. Nonetheless, there is scarce literature about the influence of parent’s level of income and perception of their children’s conditions on their decision process. Our study aims at expanding our knowledge about this parameter. We focused our research on parents of children spina bifida occulta (SBO), a condition that with a broad clinical impact and that often requires timely referral.

Methods:

Questionnaires in Mandarin were administered to parents of patients presenting to the neurosurgery clinic of a children’s hospital in Shanghai. Participants were grouped according to the level of income, above and below 50,000 Yuan. The SBO was classified into two groups, with and without evident subcutaneous mass.

Results:

One hundred and forty-five participants completed the questionnaire. Regardless of the type of lesion, families with lower income attributed their concerns for seeking care to their local physicians and the lack of health resources. Families with higher income exhibited fear of treatment. The lower income cohort presented for treatment at an older age than a higher income group. Patients with subcutaneous mass presented for treatment at a younger age than those that did not exhibit mass.

Conclusion:

Parental social economic background and visual presentation of SBO have to be factored when analyzing their decision-making process when seeking care for their children. Parental factors can be barriers to surgical care. Healthcare providers must bring parents to the forefront of the treatment process.

SOX19b regulates the premature neuronal differentiation of neural stem cells through EZH2-mediated histone methylation in neural tube development of zebrafish

Objective

Neural tube defects (NTDs) are the most serious and common birth defects in the clinic. The SRY-related HMG box B1 (SoxB1) gene family has been implicated in different processes of early embryogenesis. Sox19b is a maternally expressed gene in the SoxB1 family that is found in the region of the presumptive central nervous system (CNS), but its role and mechanism in embryonic neural stem cells (NSCs) during neural tube development have not yet been explored. Considering that Sox19b is specific to bony fish, we intended to investigate the role and mechanism of Sox19b in neural tube development in zebrafish embryos.

Material and methods

Morpholino (MO) antisense oligonucleotides were used to construct a Sox19b loss-of-function zebrafish model. The phenotype and the expression of related genes were analysed by in situ hybridization and immunolabelling. Epigenetic modifications were detected by western blot and chromatin immunoprecipitation.

Results

In this study, we found that zebrafish embryos exhibited a reduced or even deleted forebrain phenotype after the expression of the Sox19b gene was inhibited. Moreover, we found for the first time that knockdown of Sox19b reduced the proliferation of NSCs; increased the transcription levels of Ngn1, Ascl1, HuC, Islet1, and cyclin-dependent kinase (CDK) inhibitors; and led to premature differentiation of NSCs. Finally, we found that knockdown of Sox19b decreased the levels of EZH2/H3K27me3 and decreased the level of H3K27me3 at the promoters of Ngn1 and ascl1a.

Conclusion

Together, our data demonstrate that Sox19b plays an essential role in early NSC proliferation and differentiation through EZH2-mediated histone methylation in neural tube development. This study established the role of transcription factor Sox19b and epigenetic factor EZH2 regulatory network on NSC development, which provides new clues and theoretical guidance for the clinical treatment of neural tube defects.

Socioeconomic inequality in periconceptional folic acid supplementation in China: a census of 0.9 million women in their first trimester of pregnancy

Background

To assess socioeconomic inequality in periconceptional folic acid supplementation in China.

Methods

We used data of periconceptional folic acid (FA) supplementation of rural Chinese women from the National Free Preconception Health Examination Project from 2010 to 2012 and socioeconomic level data from the National Bureau of Statistics. We used logistic models to assess the associations between the prevalence of taking FA and the sociodemographic characteristics of the participants, the couples, and the socioeconomic levels of their region of residence.

Results

Of the 907,720 included women, 682,315 (75.62%) of the women reported taking FA. The prevalence of FA supplementation was significantly higher in participants aged 21–29 (75.87%) than in those women aged 40–49 (68.44%, p < 0.01). The prevalence of FA supplementation was significantly higher in the region with the highest Per Capita Gross Regional Product than in the regions with lower Per Capita Gross Regional Product (aOR = 12.20 [95% CI:9.54–15.61]). The higher the per capita net income of farmer households in the region, the higher the prevalence of FA supplementation (aOR = 1.95 [95% CI:1.74–2.18]).

Conclusions

The rate of periconceptional FA supplementation among rural Chinese women has increased with the support of China’s Health System Reform policy. However, socioeconomic disparities in periconceptional folic acid supplementation remain.

A parental perspective concerning barriers to care for neural tube defects in China

Background:

The People's Republic of China (PRC) has the highest incidence of neural tube defects (NTDs) in the world. NTDs remain a significant contributor to the global burden of disease amendable to surgical care; however, no studies to date have evaluated the patients’ perspective regarding perceived barriers to care.

Methods:

The study was conducted at the Shanghai Children's Medical Center (SCMC) between 6/11/2014 and 7/17/2014. Surveys were administered to families presenting to the clinic of the SCMC director for Pediatric Neurosurgery. Additionally, orphaned patients under the care of the Baobei Foundation were surveyed for comparison. Participants were allowed to mark as many barriers on the survey as they deemed relevant to their experience.

Results:

A total of 69 patients were surveyed. The most frequently chosen barrier to care, with a P value < 10^-5, was that the referring physician did not know enough about the child's condition. As compared to the Baobei Foundation orphans, surveyed patients presented at an older age for initial treatment (7 months versus 1 month, P value = 0.001), and visited more hospitals before reaching SCMC (3.14 versus 1.0, P value < 10^-5).

Conclusions:

The results of this study highlight the referring physician as a primary barrier to care. The younger age at time of treatment for Baobei orphans born with NTDs supports this finding, as they essentially bypassed the referral process. An elaboration on reasons for this real or perceived barrier may provide insight into a means for expedited diagnosis and treatment of NTDs within the PRC.

National and subnational all-cause and cause-specific child mortality in China, 1996-2015: a systematic analysis with implications for the Sustainable Development Goals

BACKGROUND

China has achieved Millennium Development Goal 4 to reduce under-5 mortality rate by two-thirds between 1990 and 2015. In this study, we estimated the national and subnational levels and causes of child mortality in China annually from 1996 to 2015 to draw implications for achievement of the SDGs for China and other low-income and middle-income countries.

METHODS

In this systematic analysis, we adjusted empirical data on levels and causes of child mortality collected in the China Maternal and Child Health Surveillance System to generate representative estimates at the national and subnational levels. In adjusting the data, we considered the sampling design and probability, applied smoothing techniques to produce stable trends, fitted livebirth and age-specific death estimates to natvional estimates produced by the UN for international comparison, and partitioned national estimates of infrequent causes produced by independent sources to the subnational level.

FINDINGS

Between 1996 and 2015, the under-5 mortality rate in China declined from 50·8 per 1000 livebirths to 10·7 per 1000 livebirths, at an average annual rate of reduction of 8·2%. However, 181 600 children still died before their fifth birthday, with 93 400 (51·5%) deaths occurring in neonates. Great inequity exists in child mortality across regions and in urban versus rural areas. The leading causes of under-5 mortality in 2015 were congenital abnormalities (35 700 deaths, 95% uncertainty range [UR] 28 400-45 200), preterm birth complications (30 900 deaths, 24 200-40 800), and injuries (26 600 deaths, 21 000-33 400). Pneumonia contributed to a higher proportion of deaths in the western region of China than in the eastern and central regions, and injury was a main cause of death in rural areas. Variations in cause-of-death composition by age were also examined. The contribution of preterm birth complications to mortality decreased after the neonatal period; congenital abnormalities remained an important cause of mortality throughout infancy, whereas the contribution of injuries to mortality increased after the first year of life.

INTERPRETATION

China has achieved a rapid reduction in child mortality in 1996-2015. The decline has been widespread across regions, urban and rural areas, age groups, and cause-of-death categories, but great disparities remain. The western region and rural areas and especially western rural areas should receive most attention in improving child survival through enhanced policy and programmes in the Sustainable Development Goals era. Continued investment is crucial in primary and secondary prevention of deaths due to congenital abnormalities, preterm birth complications, and injuries nationally, and of deaths due to pneumonia in western rural areas. The study also has implications for improving child survival and civil registration and vital statistics in other low-income and middle-income countries.

FUNDING

Bill & Melinda Gates Foundation.

Application potential of bone marrow mesenchymal stem cell (BMSCs) based tissue-engineering for spinal cord defect repair in rat fetuses with spina bifida aperta

Spina bifida aperta are complex congenital malformations resulting from failure of fusion in the spinal neural tube during embryogenesis. Despite surgical repair of the defect, most patients who survive with spina bifida aperta have a multiple system handicap due to neuron deficiency of the defective spinal cord. Tissue engineering has emerged as a novel treatment for replacement of lost tissue. This study evaluated the prenatal surgical approach of transplanting a chitosan-gelatin scaffold seeded with bone marrow mesenchymal stem cells (BMSCs) in the healing the defective spinal cord of rat fetuses with retinoic acid induced spina bifida aperta. Scaffold characterisation revealed the porous structure, organic and amorphous content. This biomaterial promoted the adhesion, spreading and in vitro viability of the BMSCs. After transplantation of the scaffold combined with BMSCs, the defective region of spinal cord in rat fetuses with spina bifida aperta at E20 decreased obviously under stereomicroscopy, and the skin defect almost closed in many fetuses. The transplanted BMSCs in chitosan-gelatin scaffold survived, grew and expressed markers of neural stem cells and neurons in the defective spinal cord. In addition, the biomaterial presented high biocompatibility and slow biodegradation in vivo. In conclusion, prenatal transplantation of the scaffold combined with BMSCs could treat spinal cord defect in fetuses with spina bifida aperta by the regeneration of neurons and repairmen of defective region.

Effectiveness of Folic Acid Fortified Flour for Prevention of Neural Tube Defects in a High Risk Region

Despite efforts to tackle folate deficiency and Neural Tube Defects (NTDs) through folic acid fortification, its implementation is still lacking where it is needed most, highlighting the need for studies that evaluate the effectiveness of folic acid fortified wheat flour in a poor, rural, high-risk, NTD region of China. One of the most affected regions, Shanxi Province, was selected as a case study. A community intervention was carried out in which 16,648 women of child-bearing age received fortified flour (eight villages) and a control group received ordinary flour (three villages). NTD birth prevalence and biological indicators were measured two years after program initiation at endline only. The effect on the NTD burden was calculated using the disability-adjusted life years (DALYs) method. In the intervention group, serum folate level was higher than in the control group. NTDs in the intervention group were 68.2% lower than in the control group (OR = 0.313, 95% CI = 0.207-0473, p < 0.001). In terms of DALYs, burden in intervention group was approximately 58.5% lower than in the control group. Flour fortification was associated with lower birth prevalence and burden of NTDs in economically developing regions with a high risk of NTDs. The positive findings confirm the potential of fortification when selecting an appropriate food vehicle and target region. As such, this study provides support for decision makers aiming for the implementation of (mandatory) folic acid fortification in China.

Epidemiology of Birth Defects Based on a Birth Defect Surveillance System from 2005 to 2014 in Hunan Province, China

Objective

To describe the epidemiology of birth defects (BDs) in perinatal infants in Hunan Province, China, between 2005 and 2014.

Methods

The BD surveillance data of perinatal infants (for stillbirth, dead fetus or live birth between 28 weeks of gestation and 7 days after birth) were collected from 52 registered hospitals of Hunan between 2005 and 2014. The prevalence rates of BDs with 95% confidence interval (CI) and crude odds ratio (ORs) were calculated to examine the associations of infant gender, maternal age, and region (urban vs rural) with BDs.

Results

From 2005 to 2014, there were a total of 925413 perinatal infants of which 17753 had BDs, with the average prevalence of 191.84 per 10000 PIs (perinatal infants), showing a significant uptrend. The risks of BDs are higher in urban areas versus rural areas (OR = 1.20), in male infants versus female infants (OR = 1.19), and in mothers above age 35 versus those below age 35 (OR = 1.24). The main five types of BDs are Congenital heart defects (CHD), Other malformation of external ear (OMEE), Polydactyly, Congenital malformation of kidney (CMK), and Congenital talipes equinovarus (CTE). From 2005 to 2014, the prevalence rates (per 10000 PIs) of CHD and CMK increased significantly from 22.56 to 74 (OR = 3.29, 95%CI: 2.65–4.11) and from 7.61 to 14.62 (OR = 1.92, 95%CI:1.30–2.84), respectively; the prevalence rates of congenital hydrocephalus and neural tube defects (NTDs) decreased significantly from 11.8 to 5.29 (OR = 0.45, 95%CI: 0.31–0.65) and from 7.87 to 1.74 (OR = 0.22, 95%CI: 0.13–0.38), respectively.

Conclusions

The prevalence rates of specific BDs in perinatal infants in Hunan have changed in the last decade. Urban pregnant women, male perinatal infants, and mothers above age 35 present different prevalence rates of BDs. Wider use of new diagnosis technology, improving the ability of monitoring, strengthening the publicity and education are important to reduce the prevalence of BDs.

Screening high-risk clusters for developing birth defects in mothers in Shanxi Province, China: application of latent class cluster analysis

Background

Few studies on cluster-based synthetic effects of multiple risk factors for birth defects have been reported. The present study aimed to identify maternal exposure clusters, explore the association between clusters of risk factors and birth defects, and further screen women with high risk for birth defects among expectant mothers.

Methods

Data were drawn from a large-scale, retrospective epidemiological survey of birth defects from 2006 to 2008 in six counties of Shanxi Province, China, using a three-level stratified random cluster sampling technique. Overall risk factors were extracted using eight synthetic variables summed and examined as a total risk factor score: maternal delivery age, genetic factors, medical history, nutrition and folic acid deficiency, maternal illness in pregnancy, drug use in pregnancy, environmental risk factors in pregnancy, and unhealthy maternal lifestyle in pregnancy. Latent class cluster analysis was used to identify maternal exposure clusters based on these synthetic variables. Adjusted odds ratios (AOR) were used to explore associations between clusters and birth defects, after adjusting for confounding variables using logistic regression.

Results

Three latent maternal exposure clusters were identified: a high-risk (6.15 %), a moderate-risk (22.39 %), and a low-risk (71.46 %) cluster. The prevalence of birth defects was 14.08 %, 0.85 %, and 0.52 % for the high-, middle- and low-risk clusters respectively. After adjusting for maternal demographic variables, women in the high-risk cluster were nearly 31 times (AOR: 30.61, 95 % CI: [24.87, 37.67]) more likely to have an infant with birth defects than low-risk women.

Conclusions

A high-risk group of mothers in an area with a high risk for birth defects were screened in our study. Targeted interventions should be conducted with women of reproductive age to improve neonatal birth outcomes in areas with a high risk of birth defects.

Changes in the Incidence of Congenital Anomalies in Henan Province, China, from 1997 to 2011

Aim

To investigate changes in incidence and characteristics of congenital anomalies in infants in Henan Province of China over a period of 15 years.

Methods

Population-based surveillance in Henan Province was conducted from 1997 to 2011 in 75 hospitals (40 urban districts and 35 rural counties, comprising about 20% of the total births). Basic population information was obtained from the healthcare network. All live births, intrauterine deaths after 28 weeks, and stillbirths were included. Congenital anomalies were diagnosed and reported to Henan Provincial Maternal and Pediatric Healthcare Hospital.

Results

Of 1,815,920 births from 1997 to 2011, 15,660 cases of congenital anomalies were identified, resulting in an average incidence of 86.2 cases per 10,000 births. The incidence of congenital anomalies showed a significant downward trend (p < 0.0001) in rural areas and the whole province (p < 0.0001), but an increase in urban areas (p = 0.003). The incidence was much higher in rural than in urban areas in 1997, but this discrepancy decreased rapidly and no difference was seen between rural and urban areas in 2003. The incidence in females was higher than in males in 1997–1999 but decreased to a similar level as that in males in 2000. Maternal age exceeding 35 years was associated with a higher incidence of congenital anomalies. Among the 23 types of congenital anomalies recorded, neural tube defects were the most common; the incidence declined from 39.3 cases per 10,000 births in 1997 to 6.1 cases per 10,000 births in 2011.

Conclusion

The incidence of congenital anomalies has decreased in Henan Province over the past 15 years due to significant reductions in rural areas and among girls. This decrease was partly related to a reduction in neural tube defects that was likely the result of a folic acid intervention in the province.

Epidemiology characteristics of birth defects in Shenzhen city during 2003 to 2009, China

OBJECTIVES

To explore the epidemiology characteristics of birth defects (BDs) in perinatal infants in Longgang District, Shenzhen City.

METHODS

Data used in this study was obtained from birth defects surveillance network during 2003 to 2009. The prevalence with 95% confidence interval of BDs by year, gender, household registration and type were examined. Cochran-Armitage trend tests were conducted to evaluate the tendency by year.

RESULTS

The overall prevalence of BDs in Longgang District was 13.43 (12.92, 13.95) per 1000 live births and there was an increasing trend from 2003 to 2009 in migrant and permanent population. Furthermore, the migrant population and male infant had a higher prevalence, OR = 1.22(1.09, 1.37), 1.21(1.11, 1.31) respectively. Congenital heart disease was the most common birth defect.

CONCLUSIONS

Shenzhen city is confronted with severe challenges to prevent BDs. The preventive program of BDs, especially for the migrant population, should be better performed.

Consumer preferences for micronutrient strategies in China. A comparison between folic acid supplementation and folate biofortification

OBJECTIVE

Despite public health efforts, folate deficiency is still largely prevalent in poor, rural populations and continues to cause a large burden of disease. The present paper determines and compares consumer preferences for two folate strategies: folic acid supplementation v. folate biofortification, i.e. the enhancement of the folate content in staple crops.

DESIGN

Experimental auctions with non-repeated information rounds are applied to rice in order to obtain willingness-to-pay for folate products. Thereby, GM or non-GM folate-biofortified rice (FBR) is auctioned together with rice that is supplemented with free folic acid pills (FAR).

SETTING

Shanxi Province (China) as a high-risk region of folate deficiency.

SUBJECTS

One hundred and twenty-six women of childbearing age, divided into a school (n 60) and market sample (n 66).

RESULTS

Despite differences according to the targeted sample, a general preference for folate biofortification is observed, regardless of the applied breeding technology. Premiums vary between 33·9 % (GM FBR), 36·5 % (non-GM FBR) and 19·0 % (FAR). Zero bidding behaviour as well as the product choice question, respectively, support and validate these findings. The targeted sample, the timing of the auction, the intention to consume GM food and the responsibility for rice purchases are considered key determinants of product choice. A novel ex-post negative valuation procedure shows low consistency in zero bidding.

CONCLUSIONS

While the low attractiveness of FAR provides an additional argument for the limited effectiveness of past folic acid supplementation programmes, the positive reactions towards GM FBR further support its potential as a possible complementary micronutrient intervention.

Position of folic acid in fortification of nutrition in neonatal period

Folic acid is an essential vitamin which has been known in recent 50 years. It plays an important role in period of neurogenesis. The substitution of folic acid is one of the important parts in the complex treatment of anaemia in premature newborns. It is also a component of artificial milk formulae or breast milk following mother’s intake. Fortification of foods with folic acid for population in the world is still discussed. To determine optimal dose of folic acid in premature newborns is difficult. Daily recommended doses of folic acid in infants under the six months were identified. The needs of folic acid in newborns vary. It depends upon the gestational age, body reserves at birth or maternal status of folates during gravidity. On the other hand there is a risk of accumulation of unmetabolised folic acid in circulation of newborns after mandatory folic acid fortification in some countries, which were reported in some studies. The safe upper limits of folic acid intake in premature newborns are not known. In this review article authors inform about the clear positive effect of folic acid in prenatal and neonatal period, but excessive doses of folic acid could present risk of accumulation and possible adverse effects. To follow up these notions further studies are required.

Is 5-methyltetrahydrofolate an alternative to folic acid for the prevention of neural tube defects?

Women have higher requirements for folate during pregnancy. An optimal folate status must be achieved before conception and in the first trimester when the neural tube closes. Low maternal folate status is causally related to neural tube defects (NTDs). Many NTDs can be prevented by increasing maternal folate intake in the preconceptional period. Dietary folate is protective, but recommending increasing folate intake is ineffective on a population level particularly during periods of high demands. This is because the recommendations are often not followed or because the bioavailability of food folate is variable. Supplemental folate [folic acid (FA) or 5-methyltetrahydrofolate (5-methylTHF)] can effectively increase folate concentrations to the level that is considered to be protective. FA is a synthetic compound that has no biological functions unless it is reduced to dihydrofolate and tetrahydrofolate. Unmetabolized FA appears in the circulation at doses of >200 μg. Individuals show wide variations in their ability to reduce FA. Carriers of certain polymorphisms in genes related to folate metabolism or absorption can better benefit from 5-methylTHF instead of FA. 5-MethylTHF [also known as (6S)-5-methylTHF] is the predominant natural form that is readily available for transport and metabolism. In contrast to FA, 5-methylTHF has no tolerable upper intake level and does not mask vitamin B12 deficiency. Supplementation of the natural form, 5-methylTHF, is a better alternative to supplementation of FA, especially in countries not applying a fortification program. Supplemental 5-methylTHF can effectively improve folate biomarkers in young women in early pregnancy in order to prevent NTDs.

miR-9*- and miR-124a-Mediated switching of chromatin remodelling complexes is altered in rat spina bifida aperta

Neural tube defects (NTDs) are complex congenital malformations resulting from incomplete neurulation. Our previous work has demonstrated that motor and sensory neurons develop defectively in rat embryos with spina bifida aperta. To identify whether neural development-associated miRNAs play a role in the neurological deficits of NTDs, we screened a panel of neural development-related miRNAs, including miR-9, miR-9*, miR-124a, miR-10a, miR10b, miR-34a, miR-221 and miR-222, in the spinal cords of rats with retinoic acid-induced spina bifida aperta. We discovered that the expression of miR-9, miR-9* and miR-124a was specifically down-regulated compared to spinal cords without spina bifida. To further clarify whether down-regulation of miR-9* and miR-124a contributes to the neurological deficits of NTDs, we investigated the levels of genes involved in switching in the subunit composition of Swi/Snf-like BAF (Brg/Brm associated factor) complexes modulated by miR-9* and miR-124a and neuronal differentiation. In addition to the down-regulation of miR-9* and miR-124a expression, we also observed increased expression of repressor element silencing transcription factor (REST) and BAF53a and decreased expression of BAF53b, Brg1 and NeuroD1. Our results suggest that REST-regulated miR-9*- and the miR-124a-mediated chromatin remodelling regulatory mechanism may participate in the neuronal deficits of spina bifida.

From Mice to Men: research models of developmental programming

Developmental programming can be defined as a response to a specific challenge to the mammalian organism during a critical developmental time window that alters the trajectory of development with persistent effects on offspring phenotype and predisposition to future illness. We focus on the need for studies in relevant, well-characterized animal models in the context of recent research discoveries on the challenges, mechanisms and outcomes of developmental programming. We discuss commonalities and differences in general principles of developmental programming as they apply to several species, including humans. The consequences of these differences are discussed. Obesity, metabolic disorders and cardiovascular diseases are associated with the highest percentage of morbidity and mortality worldwide. Although many of the causes are associated with lifestyle, high-energy diets and lack of physical activity, recent evidence has linked developmental programming to the epidemic of metabolic diseases. A better understanding of comparative systems physiology of mother, fetus and neonate using information provided by rapid advances in molecular biology has the potential to improve the lifetime health of future generations by providing better women's health, diagnostic tools and preventative and therapeutic interventions in individuals exposed during their development to programming influences.

Therapeutic potential of in utero mesenchymal stem cell (MSCs) transplantation in rat foetuses with spina bifida aperta

Neural tube defects (NTDs) are complex congenital malformations resulting from incomplete neurulation in embryo. Despite surgical repair of the defect, most of the patients who survive with NTDs have a multiple system handicap due to neuron deficiency of the defective spinal cord. In this study, we successfully devised a prenatal surgical approach and transplanted mesenchymal stem cells (MSCs) to foetal rat spinal column to treat retinoic acid induced NTDs in rat. Transplanted MSCs survived, grew and expressed markers of neurons, glia and myoblasts in the defective spinal cord. MSCs expressed and perhaps induced the surrounding spinal tissue to express neurotrophic factors. In addition, MSC reduced spinal tissue apoptosis in NTD. Our results suggested that prenatal MSC transplantation could treat spinal neuron deficiency in NTDs by the regeneration of neurons and reduced spinal neuron death in the defective spinal cord.

Knowledge and use of folic acid for birth defect prevention among women of childbearing age in Shanghai, China: a prospective cross-sectional study

Background

This study aimed to assess the knowledge, attitude, and practice of folic acid intake for prevention of birth defects in Chinese women of child-bearing age.

Material/Methods

In this prospective cross-sectional study, a total of 1,338 women aged 20–45 years were randomly selected for interview. Data on folic acid knowledge and information on folic acid intake in the subjects were collected. Age, education, contraception, and status of family planning were used as the independent variables in multivariate logistic regression.

Results

55.6% of the subjects took contraception at all times, and 33.9% had pregnancy planning in the next six months. 49.7% of the interviewed women knew the benefits of folic acid and 34.6% realized the correct time of folic acid intake; and 14.9% of these women actually took folic acid daily. Planning to be pregnant in the next six months was associated with knowledge of folic acid benefits, correct time of folic acid intake and actual intake. A higher education level was correlated with the knowledge of folic acid benefits and correct time of folic acid intake, but was not linked to actual intake of folic acid.

Conclusions

The knowledge and use of folic acid were at low to moderate levels in women at childbearing age in Shanghai, China, and general knowledge of folic acid benefits and correct time of folic acid intake should be conveyed to these women.

Effect modification by population dietary folate on the association between MTHFR genotype, homocysteine, and stroke risk: a meta-analysis of genetic studies and randomised trials

BACKGROUND

The MTHFR 677C→T polymorphism has been associated with raised homocysteine concentration and increased risk of stroke. A previous overview showed that the effects were greatest in regions with low dietary folate consumption, but differentiation between the effect of folate and small-study bias was difficult. A meta-analysis of randomised trials of homocysteine-lowering interventions showed no reduction in coronary heart disease events or stroke, but the trials were generally set in populations with high folate consumption. We aimed to reduce the effect of small-study bias and investigate whether folate status modifies the association between MTHFR 677C→T and stroke in a genetic analysis and meta-analysis of randomised controlled trials.

METHODS

We established a collaboration of genetic studies consisting of 237 datasets including 59,995 individuals with data for homocysteine and 20,885 stroke events. We compared the genetic findings with a meta-analysis of 13 randomised trials of homocysteine-lowering treatments and stroke risk (45,549 individuals, 2314 stroke events, 269 transient ischaemic attacks).

FINDINGS

The effect of the MTHFR 677C→T variant on homocysteine concentration was larger in low folate regions (Asia; difference between individuals with TT versus CC genotype, 3·12 μmol/L, 95% CI 2·23 to 4·01) than in areas with folate fortification (America, Australia, and New Zealand, high; 0·13 μmol/L, -0·85 to 1·11). The odds ratio (OR) for stroke was also higher in Asia (1·68, 95% CI 1·44 to 1·97) than in America, Australia, and New Zealand, high (1·03, 0·84 to 1·25). Most randomised trials took place in regions with high or increasing population folate concentrations. The summary relative risk (RR) of stroke in trials of homocysteine-lowering interventions (0·94, 95% CI 0·85 to 1·04) was similar to that predicted for the same extent of homocysteine reduction in large genetic studies in populations with similar folate status (predicted RR 1·00, 95% CI 0·90 to 1·11). Although the predicted effect of homocysteine reduction from large genetic studies in low folate regions (Asia) was larger (RR 0·78, 95% CI 0·68 to 0·90), no trial has evaluated the effect of lowering of homocysteine on stroke risk exclusively in a low folate region.

INTERPRETATION

In regions with increasing levels or established policies of population folate supplementation, evidence from genetic studies and randomised trials is concordant in suggesting an absence of benefit from lowering of homocysteine for prevention of stroke. Further large-scale genetic studies of the association between MTHFR 677C→T and stroke in low folate settings are needed to distinguish effect modification by folate from small-study bias. If future randomised trials of homocysteine-lowering interventions for stroke prevention are undertaken, they should take place in regions with low folate consumption.

FUNDING

Full funding sources listed at end of paper (see Acknowledgments).

Review of interventions for the prevention and control of folate and vitamin B12 deficiencies

Folate and vitamin B12 deficiencies represent important and evolving global health challenges that contribute to the global burden of anemia, neurologic conditions, neurodevelopmental disorders, and birth defects. We present a review of population-based programs designed to increase consumption of folates and vitamin B12. A folic acid supplementation program targeting couples prior to marriage in China has led to optimal consumption of supplements containing folic acid and a significant reduction of neural tube defects (NTD). Supplementation programs that use mass community education show some promise, but have not been shown to be as effective as targeted education. The success of supplementation programs hinges on a strong and persistent educational component and access to the supplements. Fortification with folic acid has been shown to reduce the prevalence of NTD in the countries where it has been implemented. Challenges to fortification programs include identifying the appropriate delivery vehicles, setting the optimal fortification level, sustaining the quality assurance of the fortification level, and addressing regulatory challenges and trade barriers of commercially fortified flours. Supplementation and fortification are cost-effective and viable approaches to reducing the burden of NTD, anemia, and other conditions resulting from folate deficiency. The experience with interventions involving folic acid could provide a model for the subsequent development of supplementation and fortification programs involving vitamin B12.