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

Blood folate concentrations among women of childbearing age by race/ethnicity and acculturation, NHANES 2001-2010

Hispanic women have higher rates of neural tube defects and report lower total folic acid intakes than non-Hispanic white (NHW) women. Total folic acid intake, which is associated with neural tube defect risk reduction, has been found to vary by acculturation factors (i.e. language preference, country of origin, or time spent in the United States) among Hispanic women. It is unknown whether this same association is present for blood folate status. The objective of this research was to assess the differences in serum and red blood cell (RBC) folate concentrations between NHW women and Mexican American (MA) women and among MA women by acculturation factors. Cross-sectional data from the 2001-2010 National Health and Nutrition Examination Survey (NHANES) were used to investigate how blood folate concentrations differ among NHW or MA women of childbearing age. The impact of folic acid supplement use on blood folate concentrations was also examined. MA women with lower acculturation factors had lower serum and RBC folate concentrations compared with NHW women and to their more acculturated MA counterparts. Consuming a folic acid supplement can minimize these disparities, but MA women, especially lower acculturated MA women, were less likely to report using supplements. Public health efforts to increase blood folate concentrations among MA women should consider acculturation factors when identifying appropriate interventions.

Interaction between the SLC19A1 gene and maternal first trimester fever on offspring neural tube defects

BACKGROUND

Many studies have indicated that the reduced folate carrier gene (SLC19A1) is associated with an increased risk of neural tube defects (NTDs). However, the interaction between the SLC19A1 gene variant and maternal fever exposure and NTD risk remains unknown. The aim of this study was to investigate whether the risk for NTDs was influenced by the interactions between the SLC19A1 (rs1051266) variant and maternal first trimester fever.

METHODS

We investigated the potential interaction between maternal first trimester fever and maternal or offspring SLC19A1 polymorphism through a population-based case-control study. One hundred and four nuclear families with NTDs and 100 control families with nonmal newborns were included in the study. SLC19A1 polymorphism was determined using polymerase chain reaction-restricted fragment length polymorphism.

RESULTS

Mothers who had the GG/GA genotype and first trimester fever had an elevated risk of NTDs (adjusted odds ratio, 11.73; 95% confidence interval, 3.02-45.58) as compared to absence of maternal first trimester fever and AA genotype after adjusting for maternal education, paternal education, and age, and had a significant interactive coefficient (γ = 3.17) between maternal GG/GA genotype and first trimester fever. However, there was no interaction between offspring's GG/GA genotype and maternal first trimester fever (the interactive coefficient γ = 0.97) after adjusting for confounding factors.

CONCLUSION

Our findings suggested that the risk of NTDs was potentially influenced by a gene-environment interaction between maternal SLC19A1 rs1051266 GG/GA genotype and first trimester fever. Maternal GG/GA genotype may strengthen the effect of maternal fever exposure on NTD risk in this Chinese population.

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.

Erythrocyte folate concentrations, CpG methylation at genomically imprinted domains, and birth weight in a multiethnic newborn cohort

Epigenetic mechanisms are proposed to link maternal concentrations of methyl group donor nutrients with the risk of low birth weight. However, empirical data are lacking. We have examined the association between maternal folate and birth weight and assessed the mediating role of DNA methylation at nine differentially methylated regions (DMRs) of genomically imprinted genes in these associations. Compared with newborns of women with folate levels in the lowest quartile, birth weight was higher in newborns of mothers in the second (β = 143.2, se = 63.2, P = 0.02), third (β = 117.3, se = 64.0, P = 0.07), and fourth (β = 133.9, se = 65.2, P = 0.04) quartiles, consistent with a threshold effect. This pattern of association did not vary by race/ethnicity but was more apparent in newborns of non-obese women. DNA methylation at the PLAGL1, SGCE, DLK1/MEG3 and IGF2/H19 DMRs was associated with maternal folate levels and also birth weight, suggestive of threshold effects. MEG3 DMR methylation mediated the association between maternal folate levels and birth weight (P =0.06). While the small sample size and partial scope of examined DMRs limit our conclusions, our data suggest that, with respect to birth weight, no additional benefits may be derived from increased maternal folate concentrations, especially in non-obese women. These data also support epigenetic plasticity as a key mechanistic response to folate availability during early fetal development.

The role of the folic acid to the prevention of orofacial cleft: an epidemiological study

BACKGROUND

Orofacial clefts (OFCs) have complex and multifactorial etiologies. Periconceptional folic acid supplementation can significantly reduce the risk of OFC.

OBJECTIVE

To evaluate the role of folate and other factors in preventing OFC by analyzing the health and socio-demographic data collected from a population sample.

METHODS

Retrospective case-control study in which mothers with children with or without OFC were evaluated for the following main parameters: nutritional factors, socio-demographic characteristics, pregnancy and family history, use of folate, and counseling by healthcare professionals.

RESULTS

Socio-epidemiological analysis of the 80 participants, 40 in the case group and 40 in the control group, found a significant impact on the risk of OFC related to economic and educational status. The mothers who had a diet rich in vegetables and white meat had a lower risk of having children with OFC. A short interval between pregnancies, subsequent pregnancy while still breastfeeding, and family history also increased risk of OFC.

CONCLUSIONS

Limited family planning, diet low in folate, and inadequate use of folate during the periconceptional period and during the first trimester of pregnancy were demonstrated a potential correlation with a high incidence of OFC in this study.

Changes in folic acid supplementation behaviour among women of reproductive age after the implementation of a massive supplementation programme in China

OBJECTIVE

To examine changes in periconceptional folic acid supplementation behaviour among Chinese women of reproductive age after the implementation of a folic acid supplementation programme.

DESIGN

Two cross-sectional surveys were conducted.

SETTING

One survey was before (2002-2004) and the other was after (2011-2012) implementation of the programme, both were conducted in two areas of China with different prevalence of neural tube defects. Information on supplementation behaviours was collected in face-to-face interviews with women early in their pregnancy.

SUBJECTS

A total of 1257 and 1736 pregnant women participated before and after the programme, respectively.

RESULTS

The rate of periconceptional folic acid supplementation increased from 15 % to 85 % in the high-prevalence population and from 66 % to 92 % in the low-prevalence population. However, more than half of the women began taking the supplement after learning they were pregnant. The proportion of women who began taking folic acid before their last menstrual period decreased after the programme in rural areas with both a high and low prevalence of neural tube defects.

CONCLUSIONS

Although periconceptional folic acid supplementation among Chinese women increased substantially after the programme, supplementation was often initiated too late to be effective in preventing neural tube defects. Educational and promotional campaigns should focus on how to increase the rate of folic acid supplementation before pregnancy.

Assessing the prevalence of spina bifida and encephalocele in a Kenyan hospital from 2005-2010: implications for a neural tube defects surveillance system

Introduction

Neural tube defects such as anencephaly, spina bifida, and encephalocele are congenital anomalies of the central nervous system. Data on the prevalence of neural tube defects in Kenya are limited. This study characterizes and estimates the prevalence of spina bifida and encephalocele reported in a referral hospital in Kenya from 2005-2010.

Methods

Cases were defined as a diagnosis of spina bifida or encephalocele. Prevalence was calculated as the number of cases by year and province of residence divided by the total number of live-births per province.

Results

From a total of 6,041 surgical records; 1,184 (93%) had reported diagnosis of spina bifida and 88 (7%) of encephalocele. Estimated prevalence of spina bifida and encephalocele from 2005-2010 was 3.3 [95% Confidence Interval (CI): 3.1-3.5] cases per 10,000 live-births. The highest prevalence of cases were reported in 2007 with 4.4 (95% CI: 3.9-5.0) cases per 10,000 live-births. Rift Valley province had the highest prevalence of spina bifida and encephalocele at 6.9 (95% CI: 6.3-7.5) cases per 10,000 live-births from 2005-2010.

Conclusion

Prevalence of spina bifida and encephalocele is likely underestimated, as only patients seeking care at the hospital were included. Variations in regional prevalence could be due to referral patterns and healthcare access. Implementation of a neural tube defects surveillance system would provide a more thorough assessment of the burden of neural tube defects in Kenya.

Prevention of congenital malformations and other adverse pregnancy outcomes with 4.0 mg of folic acid: community-based randomized clinical trial in Italy and the Netherlands

BACKGROUND

In 2010 a Cochrane review confirmed that folic acid (FA) supplementation prevents the first- and second-time occurrence of neural tube defects (NTDs). At present some evidence from observational studies supports the hypothesis that FA supplementation can reduce the risk of all congenital malformations (CMs) or the risk of a specific and selected group of them, namely cardiac defects and oral clefts. Furthermore, the effects on the prevention of prematurity, foetal growth retardation and pre-eclampsia are unclear.Although the most common recommendation is to take 0.4 mg/day, the problem of the most appropriate dose of FA is still open.The aim of this project is to assess the effect a higher dose of peri-conceptional FA supplementation on reducing the occurrence of all CMs. Other aims include the promotion of pre-conceptional counselling, comparing rates of selected CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age, abruptio placentae.

METHODS/DESIGN

This project is a joint effort by research groups in Italy and the Netherlands. Women of childbearing age, who intend to become pregnant within 12 months are eligible for the studies. Women are randomly assigned to receive 4 mg of FA (treatment in study) or 0.4 mg of FA (referent treatment) daily. Information on pregnancy outcomes are derived from women-and-physician information.We foresee to analyze the data considering all the adverse outcomes of pregnancy taken together in a global end point (e.g.: CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age). A total of about 1,000 pregnancies need to be evaluated to detect an absolute reduction of the frequency of 8%. Since the sample size needed for studying outcomes separately is large, this project also promotes an international prospective meta-analysis.

DISCUSSION

The rationale of these randomized clinical trials (RCTs) is the hypothesis that a higher intake of FA is related to a higher risk reduction of NTDs, other CMs and other adverse pregnancy outcomes. Our hope is that these trials will act as catalysers, and lead to other large RCTs studying the effects of this supplementation on CMs and other infant and maternal outcomes.

TRIAL REGISTRATION

Italian trial: ClinicalTrials.gov Identifier: NCT01244347.Dutch trial: Dutch Trial Register ID: NTR3161.

Short- and long-term treatment with folic acid suppresses thrombus formation in atherogenic mice in vivo

In the present study, we examined the effects of short- and long-term treatment with folic acid (FA) on thrombus formation in vivo in atherogenic mice to explore a novel agent for the prevention of atherothrombotic disease. Apolipoprotein E and low-density lipoprotein receptor double deficient (ApoE(-/-)LDLR(-/-)) mice were orally administrated a single bolus of FA (20mg/kg) or fed an atherogenic diet with or without FA (0.02, 0.5, and 1.5mg/kg) for 12 weeks. Thrombus formation and endothelial function were assessed in vivo using the He-Ne laser-induced carotid artery thrombus formation test and the flow-mediated vasodilation method. Platelet reactivity was assessed ex vivo using haemostatometry. Short-term treatment with FA markedly increased plasma folate levels and significantly suppressed laser-induced thrombus formation in apoE(-/-)LDLR(-/-) mice. Short-term treatment with FA suppressed platelet reactivity in apoE(-/-)LDLR(-/-) mice, but FA treatment did not affect endothelial function or plasma homocysteine levels. Long-term treatment with FA increased plasma folate levels dose-dependently. Thrombus formation and endothelial dysfunction were suppressed by treatment with 0.5 and 1.5mg/kg of FA, respectively, but not with 0.02mg/kg of FA, whereas platelet reactivity was not altered by treatment with any dose of FA. Long-term treatment with all doses of FA decreased the plasma homocysteine levels in apoE(-/-)LDLR(-/-) mice, although this result was not consistent with its anti-thrombotic action. In conclusion, our data showed that short- and long-term treatment with FA could suppress in vivo thrombus formation in an atherogenic setting, independent of its hypohomocysteinemic action.

Folic acid supplementation and interpregnancy interval

BACKGROUND

Maternal folic acid supplementation between subsequent pregnancies may be important to reduce the risk of low folate status associated with short interpregnancy intervals. We examined how the prevalence of preconception folic acid use for a given pregnancy in Norwegian women varied according to the time interval from the previous pregnancy.

METHODS

Analysis was based on 48 855 pairs of pregnancies with the second pregnancy included in the Norwegian Mother and Child Cohort Study (birth years 1999-2009). Interpregnancy interval was defined as the time from birth of a child to the conception of the subsequent sibling. Preconception folic acid use was defined as any use of folic acid-containing supplements within the last 4 weeks before the second pregnancy.

RESULTS

The prevalence of preconception folic acid use was 31%. Among women with a term birth (≥37 weeks) in the previous pregnancy (92%), those with interpregnancy intervals ≤12 and ≥49 months were associated with up to 35% lower prevalence of preconception folic acid use for the second pregnancy, relative to the reference group (13-24 months). The low use in short intervals was mainly attributable to lower proportion of planned pregnancies and fewer women with higher education. Among women with a preterm birth (<37 weeks) in the previous pregnancy (8%), preconception folic acid use significantly decreased with increasing pregnancy spacing.

CONCLUSIONS

Our finding of a lower preconception folic acid use in women with both short and long interpregnancy intervals might help identifying those with higher risk of folate deficiency and preventing unwanted pregnancy outcomes.

Risk factors for the occurrence of spina bifida (a case-control study) and the prevalence rate of spina bifida in Japan

BACKGROUND

The Japanese government recommended in 2000 that women planning pregnancy should take 400 μg of folic acid daily to decrease the risk of having an infant with spina bifida. We aimed to identify risk factors for the occurrence of spina bifida and to evaluate how the prevalence rate has altered over the past 3 decades.

METHODS

Subjects comprised 360 women who gave birth to spina bifida-affected offspring and 2333 women who gave birth to offspring without spina bifida between 2001 and 2012. A self-administered questionnaire was used to collect data, which were analyzed by multiple logistic regression models. The prevalence rate of spina bifida was obtained through data provided by international and domestic organizations.

RESULTS

Four variables were significantly associated with the increased risk of having newborns afflicted with spina bifida: not taking folic acid supplements (odds ratios [OR], 2.50; 95% confidence interval [CI], 1.72-3.64), presence of spina bifida patients within third-degree relatives (OR, 4.26; 95% CI, 1.12-16.19), taking anti-epileptic drugs without folic acid (OR, 20·20; 95% CI, 2.06-198.17), and low birth weight in the newborns ≤ 2500 g (OR, 4.21; 95% CI, 3.18-5.59). The prevalence rate of spina bifida has remained 5 to 6 per 10,000 total births and has not shown any decreasing trend over the past 11 years.

CONCLUSION

Four risk factors were identified among Japanese women. Because recommendations and information have not decreased the occurrence of spina bifida, the Japanese government should implement mandatory food fortification.

Association analysis between MTHFR genetic polymorphisms and the risk of congenital heart diseases in Chinese Han population

OBJECTIVES

Congenital heart diseases (CHD) are common birth defects in the world. The methylenetetrahydrofolate reductase (MTHFR) gene is one of the most important candidate genes for the development of CHD. This case-control study aimed to evaluate the effect of MTHFR c.382A>G and c.1129C>T genetic polymorphisms as risk factors for the development of CHD.

METHODS

A total of 230 CHD patients and 237 non-CHD controls were included in the present study. The genotyping of MTHFR c.382A>G and c.1129C>T genetic polymorphisms were detected by the polymerase chain reaction-restriction fragment length polymorphism and created restriction site-polymerase chain reaction methods, respectively.

KEY FINDINGS

The alleles/genotypes distribution from these two genetic polymorphisms were statistically associated with the increased risk of CHD (for c.382A>G, GG versus AA: odds ratio (OR) = 2.39, 95% confidence interval (CI), 1.27 to 4.52, P = 0.006; for c.1129C>T, TT versus CC: OR = 2.73, 95% CI, 1.33 to 5.62, P = 0.005). The allele G and genotype GG of c.382A>G and allele T and genotype TT of c.1129C>T genetic polymorphisms might contribute to CHD susceptibility.

CONCLUSION

These preliminary findings indicate that these two MTHFR genetic polymorphisms are related with the risk of CHD in Chinese Han population, and might be potentially utilized as molecular markers.

Periconceptional folic acid supplementation and the risk of preterm births in China: a large prospective cohort study

BACKGROUND

Folic acid-containing multivitamins have been associated with a reduced risk of preterm birth. We examined whether periconceptional use of folic acid alone reduced this risk.

METHODS

Data were derived from a large population-based cohort study conducted in China to evaluate the prevention of neural tube defects with folic acid supplementation. The sample comprised 207 936 singleton live births delivered at gestational ages of 20-42 weeks to women from two provinces in southern China. Healthcare workers recorded folic acid intake prospectively each month. Gestational age calculation was based on the first day of the last menstrual period. Preterm births were categorized into three clinical subtypes: iatrogenic preterm birth, preterm premature rupture of membranes (PPROM) and spontaneous preterm birth. Logistic regression was used to evaluate the association between folic acid use and the risk of preterm birth, adjusting for potential confounders.

RESULTS

The incidence of preterm birth was significantly lower among folic acid users (5.28%) than among non-users (6.10%). Folic acid use showed a 14% risk reduction for preterm birth overall [adjusted risk ratio (RR) = 0.86, 95% confidence interval (CI) 0.82-0.90]. This association was strongest for spontaneous preterm birth (adjusted RR = 0.81, 95% CI 0.78-0.86) and was not significant for iatrogenic preterm birth (adjusted RR = 0.97, 95% CI 0.88-1.07) or PPROM (adjusted RR = 1.07, 95% CI 0.93-1.23).

CONCLUSIONS

Daily intake of 400 μg folic acid alone during the periconceptional period was associated with a reduced risk of spontaneous preterm birth.

Folic acid supplementation and preterm birth: results from observational studies

INTRODUCTION

Folic acid (FA) supplementation is recommended worldwide in the periconceptional period for the prevention of neural tube defects. Due to its involvement in a number of cellular processes, its role in other pregnancy outcomes such as miscarriage, recurrent miscarriage, low birth weight, preterm birth (PTB), preeclampsia, abruptio placentae, and stillbirth has been investigated. PTB is a leading cause of perinatal mortality and morbidity; therefore its association with FA supplementation is of major interest. The analysis of a small number of randomized clinical trials (RCTs) has not found a beneficial role of FA in reducing the rate of PTBs.

AIM OF THE STUDY

The aim of this review was to examine the results from recent observational studies about the effect of FA supplementation on PTB.

MATERIALS AND METHODS

We carried out a search on Medline and by manual search of the observational studies from 2009 onwards that analyzed the rate of PTB in patients who received supplementation with FA before and/or throughout pregnancy.

RESULTS

The results from recent observational studies suggest a slight reduction of PTBs that is not consistent with the results from RCTs. Further research is needed to better understand the role of FA supplementation before and during pregnancy in PTB.

Neural tube defects in Latin America and the impact of fortification: a literature review

OBJECTIVE

Data on the prevalence of birth defects and neural tube defects (NTD) in Latin America are limited. The present review summarizes NTD prevalence and time trends in Latin American countries and compares pre- and post-fortification periods to assess the impact of folic acid fortification in these countries.

DESIGN

We carried out a literature review of studies and institutional reports published between 1990 and 2010 that contained information on NTD prevalence in Latin America.

RESULTS

NTD prevalence in Latin American countries varied from 0·2 to 9·6 per 1000 live births and was influenced by methods of ascertainment. Time trends from Bogota, Costa Rica, Dominican Republic, Guatemala City, Mexico and Puerto Rico showed average annual declines of 2·5 % to 21·8 %. Pre- and post-fortification comparisons were available for Argentina, Brazil, Chile, Costa Rica, Puerto Rico and Mexico. The aggregate percentage decline in NTD prevalence ranged from 33 % to 59 %.

CONCLUSIONS

The present publication is the first to review data on time trends and the impact of folic acid fortification on NTD prevalence in Latin America. Reported NTD prevalence varied markedly by geographic region and in some areas of Latin America was among the lowest in the world, while in other areas it was among the highest. For countries with available information, time trends showed significant declines in NTD prevalence and these declines were greater in countries where folic acid fortification of staples reached the majority of the population at risk, such as Chile and Costa Rica.

Increasing prevalence, changes in diagnostic criteria, and nutritional risk factors for autism spectrum disorders

The frequency of autism spectrum disorders (ASD) diagnoses has been increasing for decades, but researchers cannot agree on whether the trend is a result of increased awareness, improved detection, expanding definition, or an actual increase in incidence or a combination of these factors. Though both genetic and multiple environmental risk factors have been studied extensively, many potentially modifiable risk factors including nutritional and immune function related risk factors such as vitamin D, folic acid, and metabolic syndrome have not received sufficient attention. Several recent studies have put forward hypotheses to explain the mechanism of association between both folic acid and vitamin D and autism. A continuous rise in the prevalence of autism in the USA has coincided with a significant enhancement of maternal folate status with FDA mandated folic acid fortification of certain foods starting in 1998. There is also a growing body of research that suggests that vitamin D status either in utero or early in life may be a risk for autism. In this communication, controversies regarding increase in estimate of prevalence, implications of changes in definition, and possible association between some modifiable nutritional risk factors such as folic acid and vitamin D and ASD will be discussed.

Metabonomic profiling of human placentas reveals different metabolic patterns among subtypes of neural tube defects

Neural tube defects (NTDs) are one of the most common types of birth defects with a complex etiology. We have previously profiled serum metabolites of pregnant women in Lvliang prefecture, Shanxi Province of China, which revealed distinct metabolic changes in pregnant women with NTDs outcome. Here we present a metabonomics study of human placentas of 144 pregnant women with normal pregnancy outcome and 115 pregnant women affected with NTDs recruited from four rural counties (Pingding, Xiyang, Taigu, and Zezhou) of Shanxi Province, the area with the highest prevalence worldwide. A panel of 19 metabolites related to one-carbon metabolism was also quantitatively determined. We observed obvious differences in global metabolic profiles and one-carbon metabolism among three subtypes of NTDs, anencephaly (Ane), spina bifida (SB), and Ane complicated with SB (Ane & SB) via mass-spectrometry-based metabonomics approach. Disturbed carbohydrate, amino acid, lipid, and nucleic acid metabolism were identified. Placental transport of amino acids might be depressed in Ane and Ane & SB group. Deficiency of choline contributes to Ane and Ane & SB pathogenesis via different metabolic pathways. The formation of NTDs seemed to be weakly related to folates. The metabonomic analysis reveals that the physiological and biochemical processes of the three subtypes of NTDs might be different and the subtype condition should be considered for the future investigation of NTDs.

Association of sociodemographic and nutritional factors with risk of neural tube defects in the North Indian population: a case-control study

OBJECTIVE

To assess the role of sociodemographic and nutritional factors in the incidence of births affected by neural tube defects (NTD) in the North Indian population.

DESIGN

Case-control study.

SETTING

Government hospitals of Delhi, India.

SUBJECTS

Subjects comprised 284 mothers of NTD children (cases) and 568 mothers of healthy children (controls).

RESULTS

Significant differences were found between case and control mothers with respect to maternal age (P = 0·005), type of drinking water (P = 0·03) and consumption of milk (P = 0·01). Univariate and multivariate analysis suggested an association of unpasteurized milk use, low consumption of vegetables, low consumption of fruits and vegetarian dietary habits with NTD births. Further, variation in the risk factors for upper and lower NTD types was also observed, pointing towards phenotypic heterogeneity in the aetiology.

CONCLUSIONS

The results of the present study suggest an increased risk of NTD infants in mothers with low consumption of vegetables, fruits and milk and having vegetarian dietary habits. So, in order to reduce these devastating birth defects in future offspring, better nutritional care should be provided to mothers by suggesting dietary modifications and augmenting additional micronutrient supplementation during the periconceptional period.

C677T mutation in methylenetetrahydrofolate reductase gene and neural tube defects: should Japanese women undergo gene screening before pregnancy?

We analyzed the role of maternal C677T mutation in methylenetetrahydrofolate reductase (MTHFR) gene on spina bifida development in newborns. A total of 115 mothers who had given birth to a spina bifida child (SB mothers) gave 10 mL of blood together with written informed consent. The genotype distribution of C677T mutation was assessed and compared with that of the 4517 control individuals. The prevalence of the homozygous genotype (TT) among SB mothers was not significantly different from that among the controls (odds ratio [OR] = 0.65; 95% confidence interval [CI] = 0.31-1.25; P = 0.182), suggesting that MTHFR 677TT genotype in Japan is not associated with spina bifida development in newborns. The T allele frequency was not increased in SB mothers (34.8%) as compared to that of the control individuals (38.2%). Further, the internationally reported association between the two groups was found to be similar in all 15 countries studied except the Netherlands, where the TT genotype was found to be a genetic risk factor for spina bifida. For the prevention of affected pregnancy every woman planning to conceive has to take folic acid supplements 400 μg a day and the government is asked to take action in implementing food fortification with folic acid in the near future. In conclusion, it is not necessary for Japanese women to undergo genetic screening C677T mutation of the MTHFR gene as a predictive marker for spina bifida prior to pregnancy, because the TT genotype is not a risk factor for having an affected infant.

Caesarean delivery, caesarean delivery on maternal request and childhood overweight: a Chinese birth cohort study of 181 380 children

What is already known about this subject Both rates of caesarean section and childhood overweight have been steadily increasing over the past decade in many parts of the world. Caesarean delivery on maternal request contributes remarkably to the rising trend of caesarean births. A few small-scale studies suggest that caesarean section may be associated with later overweight and obesity, whereas little is known about the impact of caesarean delivery on maternal request. What this study adds Caesarean section is associated with an increased risk of childhood overweight. Children born by caesarean delivery on maternal request are also more likely to be overweight. The strength of the caesarean-overweight association is modest.

OBJECTIVES

To assess the impact of caesarean delivery including non-medically indicated maternal request caesarean delivery on childhood overweight.

METHODS

We conducted a prospective investigation of a Chinese birth cohort involving 181 380 children, who were born during 1993-1996 to mothers registered in a perinatal care surveillance system and whose weight and height were measured in 2000. Information on delivery mode and covariates was obtained from the surveillance system. Overweight was defined according to the International Obesity Task Force body mass index (BMI) cutoffs. Multivariable logistic regression was used to estimate adjusted odds ratios. Stratified analyses were done to test whether the association between caesarean section and overweight persisted across subgroups.

RESULTS

The adjusted odds ratio of overweight for children born by caesarean compared with vaginal delivery was 1.13 [95% confidence interval {CI}: 1.08, 1.18]. The association persisted in subgroups stratified by gender, maternal education, maternal BMI, weight gain during pregnancy and child birthweight (all P values for interaction test ≥0.30). The adjusted odds ratio of overweight for children born by non-medically indicated caesarean delivery compared with vaginal delivery was 1.18 (95% CI: 1.00, 1.41).

CONCLUSION

Caesarean delivery including non-medically indicated maternal request caesarean delivery compared with vaginal delivery modestly increases childhood overweight risk.

Maternal smoking during pregnancy and neural tube defects in offspring: a meta-analysis

PURPOSE

This study aims to examine the association between maternal smoking during pregnancy and neural tube defects (NTDs) in offspring.

METHODS

We retrieved published studies on the association between maternal smoking during pregnancy and NTDs risk in offspring. Meta-analysis was applied to calculate the overall odds ratios (ORs) and their 95 % confidence intervals (CIs). The publication bias was assessed by the Egger's regression asymmetry test and Begg's rank correlation test.

RESULTS

The overall effect of maternal smoking during pregnancy on NTDs was 1.03 (OR = 1.03, 95 % CI = 0.80-1.33). When subgroup analysis was conducted by geographic regions, the overall effects were 1.39 (OR = 1.39, 95 % CI = 1.18-1.64), 0.88 (OR = 0.88, 95 % CI = 0.66-1.17) in Europe and USA; when subgroup analysis was conducted by NTDs types, the overall effect was 1.55 (OR = 1.55, 95 % CI = 1.06-2.26) for spina bifida.

CONCLUSIONS

Women who smoked during pregnancy had mildly elevated risk of having infants with NTDs.

Environmental alterations of epigenetics prior to the birth

The etiology of many brain diseases remains allusive to date after intensive investigation of genomic background and symptomatology from the day of birth. Emerging evidences indicate that a third factor, epigenetics prior to the birth, can exert profound influence on the development and functioning of the brain and over many neurodevelopmental syndromes. This chapter reviews how aversive environmental exposure to parents might predispose or increase vulnerability of offspring to neurodevelopmental deficit through alteration of epigenetics. These epigenetic altering environmental factors will be discussed in the category of addictive agents, nutrition or diet, prescriptive medicine, environmental pollutant, and stress. Epigenetic alterations induced by these aversive environmental factors cover all aspects of epigenetics including DNA methylation, histone modification, noncoding RNA, and chromatin modification. Next, the mechanisms how these environmental inputs influence epigenetics will be discussed. Finally, how environmentally altered epigenetic marks affect neurodevelopment is exemplified by the alcohol-induced fetal alcohol syndrome. It is hoped that a thorough understanding of the nature of prenatal epigenetic inputs will enable researchers with a clear vision to better unravel neurodevelopmental deficit, late-onset neuropsychiatric diseases, or idiosyncratic mental disorders.

Nutritional status of the elderly in rural North China: a cross-sectional study

OBJECTIVES

This study aimed to describe the nutritional status of elderly people living in a rural area of North China.

DESIGN

Community-based, cross-sectional prevalence survey.

SETTING

3 rural towns of Lvliang City, Shanxi Province, China.

PARTICIPANTS

A sample of 1845 community residents (29.1% of those eligible) 55 years or older (birth before 1958-01-01).

MEASUREMENTS

The participants were assessed regarding demographic characteristics, height, weight, as well as having a physical examination and blood sampling for serum cholesterol, total homocysteine (tHcy), folate, and vitamin B12 levels.

RESULTS

991 (53.7%) were female and 139 (7.5%) did not complete the anthropometric measurement. Prevalence of underweight and obesity was 3.5% and 24.9% in men and 6.7% and 31.0% in women (P = 0.003, P = 0.005, respectively). Prevalence of hypercholesterolemia and hypocholesterolemia was 13.5% and 52.6% in men and 25.0% and 34.3% in women (P < 0.001, P < 0.001, respectively). Prevalence of high LDL-c concentrations was 8.8% in men and 16.8% in women (P < 0.001). The mean serum tHcy in men (28.8 ± 20.1 μmmol/l) was significantly higher than in women (21.0 ± 15.1 μmmol/L, P < 0.001). Prevalence of hyperhomocysteinemia (defined as > 15μmmol/L) was 79.7% in men and 65.5% in women (P < 0.001). Prevalence of low folate (defined as < 11 nmol/L) and vitamin B12 levels (defiend as < 185 pmol/L) was 70.8 % and 76.8% in men and 56.5% and 72.6% in women (P < 0.001, P = 0.036, respectively). Correlation coefficients between tHcy, folate, and vitamin B12 indicated an inverse linear correlation (r = -0.21, P < 0.001, r = -0.35, P < 0.001, respectively).

CONCLUSIONS

As China's economic climate has developed, the nutritional status of elderly people in the rural parts of the country has improved in some aspects. However, the trend toward obesity will lead to a shift in the burden of obesity-related chronic diseases. In addition, rurally-located elderly people are at high risk of death that may be associated with abnormal serum cholesterol. The data also suggest that severe deficiencies in folate and vitamin B12 levels exist, as well as there being a high prevalence of hyperhomocysteinemia. Folate and vitamin B12 supplementation are necessary to prevent related diseases.

Association between maternal COMT gene polymorphisms and fetal neural tube defects risk in a Chinese population

Maternal tea consumption was reported to increase the risk of fetal neural tube defects (NTDs). Catechol-O-methyltransferase (COMT) may be involved in the metabolism of polyphenolic methylation of tea, thus influence the risk of fetal NTDs.

METHODS

A total of 576 fetuses or newborns with NTDs and 594 healthy newborns were included in the case-control study. Information on maternal tea consumption, sociodemographic characteristics, reproductive history, and related behavior was collected through face-to-face interviews. Maternal blood samples were collected to examine polymorphisms in COMT, and the possible interaction of COMT and tea consumption was analyzed.

RESULTS

After controlling for potential confounders, homozygotes of rs737865 showed an elevated risk for total NTDs (odds ratio [OR] = 2.04, 95% confidence interval [CI], 1.24-3.35) and for the anencephaly subtype (OR = 1.99, 95% CI, 1.17-3.39). The CC genotype of rs4633 was positively associated with the overall risk of NTDs (OR = 3.66, 95% CI, 1.05-12.83). Heterozygotes for rs4680 were associated with a decreased risk of spina bifida (OR = 0.71, 95% CI, 0.51-0.98). The COMT rs4680 A allele was negatively related with the risk of spina bifida, with adjusted OR = 0.64 (95% CI, 0.45-0.89). An interaction between tea consumption (1 to 2 cups/day) and the rs4680AA/AG genotype was found in the spina bifida subtype (Pinteraction  = .08).

CONCLUSION

Several COMT variants were associated with elevated risk of NTDs in a Chinese population. Maternal tea consumption may be associated with an increased risk for fetal NTDs in genetically susceptible subgroups.

Supplement Use Among Pregnant Women in Ethiopia: Prevalence and Predictors

Purpose The purpose of this article was to assess the pattern of supplement use and associated factors among pregnant women in Ethiopia. Methods A facility-based cross-sectional study was conducted. A total of 339 pregnant women were included in the study, 63 (18.3%) and 23 (6.8%) of whom used at least 1 supplement during pregnancy and 2 to 4 weeks prior to pregnancy, respectively. Only 3 women were prescribed folic acid during pregnancy. The pregnant women were interviewed to collect supplements use and pregnancy-related information through a pretested semistructured questionnaire. Subsequent charts of prescribed supplements were reviewed using a pretested data collection format. Results The majority (76.4%) of the women claimed no awareness about the benefits of early supplementation. Supplement use was about 8 times higher among women with > 3 children (adjusted odds ratio, 7.85; 95% confidence interval, 1.69-36.28; P = .008) than among nulliparous women, and about 6 times higher among women in their second trimester (adjusted odds ratio, 6.26; 95% confidence interval, 1.91-20.55; P = .03) of pregnancy compared to those women in their first trimester. Conclusion Overall supplement use, particularly folic acid intake, was found to be negligible during the prenatal as well as antenatal periods. The majority of the women in the study lacked awareness about the benefits of supplementation and potential risks associated with the absence of folic acid during pregnancy. Information by the media and health care personnel given to childbearing women about the need to take folic acid to prevent neural tube defects seems to improve the intake of folic acid during the protective period.

[Changes in life styles of pregnant women and risks for having a pregnancy afflicted with spina bifida]

AIMS

Though periconceptional intakes of folic acid could prevent the occurrence of spina bifida by 50 to 70%, the prevalence has not shown any decreasing tendency during the past 30 years in Japan. We aim to analyze various parameters through life style questionnaires and 3-day food records obtained from pregnant women the last 10 years, and to examine whether their life styles have been shifting to the direction of lowering the incidence of spina bifida.

MATERIALS AND METHODS

Life style questionnaires inquired of knowledge of folic acid in relation to preventing spina bifida during a pregnancy and other relevant parameters, which were collected from 11,861 participants during a period of from 2002 to 2011. Food records asked participants to semi-quantitatively describe diets and beverages they consumed for a 3-day period, which were collected from 1,081 pregnant women from 2003 to 2011.

RESULTS

Life style questionnaires demonstrated that knowledge of folic acid and the proportion of those who took folic acid supplements elevated from 15.3 and 9.1% in 2002 to 43.7 and 61.5% in 2011, respectively, that comparison of those who took folic acid supplements from 2008 to 2011 residing in one of 8 districts of Japan showed a significant difference, i.e., the proportion of those in the Chugoku or Kyushu district being significantly lower compared to that in the Hokkaido district, and that other life style parameters have not much altered the past 9 years, e.g., those who conceived as planed being 67%, those who confirmed own pregnancy within 6 weeks of pregnancy being 70%, those who took balanced diets being 65%, and those who did not smoke or drink being 95% and 96%, respectively. Three-day food records revealed that the mean dietary folate intakes ranged from 260 to 360 microg/day in each year which were less than the recommended dietary allowance (RDA) publicized by the government, but that the proportion of pregnant women in the first trimester who consumed folic acid supplements from 4 weeks prior to to 12 weeks after conception increased from 7.4% in 2003 to 69.6% in 2011.

CONCLUSIONS

As a whole it could be stated that life styles of pregnant women have been shifting toward the direction the past 10 years where the risk for having a pregnancy afflicted with spina bifida is to be decreased. Medical doctors, nurses, midwives, dietitians and pharmacists are asked to repeatedly supply important information on folic acid and to advise taking folic acid supplements 400 microg a day to women planning to conceive or women in the reproductive age.

A review of the social, psychological, and economic burdens experienced by people with spina bifida and their caregivers

INTRODUCTION

Despite measures to reduce the incidence of neural tube defects (NTDs), the rate of decline has not been as dramatic as expected. At least 300,000 newborns worldwide are known to be affected by NTDs each year. This comprehensive literature review summarizes the human and economic burden of NTDs to patients and caregivers, with particular focus on spina bifida (SB).

METHODS

PubMed, PsycINFO, and Embase were searched for studies from January 1976 to November 2010 that included clinical terms, such as NTD, and at least one patient-reported outcome or cost term. A conceptual model was also developed.

RESULTS

Areas of peoples' lives affected by SB included physical and role functioning, activities of daily living, bodily pain, vitality, emotional functioning, mental health, self-esteem, self-image, social functioning, relationships, and sexual functioning. Areas of caregivers' lives affected included activities of daily living, work impact, time consumption, parental responsibilities (including responsibilities to other children), confidence, feelings and emotions, mental health, stress, social impact, psychological adjustment, relationships (with SB child, siblings, other family members), social support, coping strategies, and termination decisions. Cost burdens on patients and caregivers also include out-of-pocket costs, lost wages, or household production due to increased morbidity and mortality, transportation and other nonmedical costs.

CONCLUSIONS

This review highlights the need to provide care and support to individuals with SB and their caregivers. Results also emphasize the importance of effective long-term public health campaigns and/or newer strategies to prevent NTDs, such as SB.

Folate deficiency and folic acid supplementation: the prevention of neural-tube defects and congenital heart defects

Diet, particularly vitamin deficiency, is associated with the risk of birth defects. The aim of this review paper is to show the characteristics of common and severe neural-tube defects together with congenital heart defects (CHD) as vitamin deficiencies play a role in their origin. The findings of the Hungarian intervention (randomized double-blind and cohort controlled) trials indicated that periconceptional folic acid (FA)-containing multivitamin supplementation prevented the major proportion (about 90%) of neural-tube defects (NTD) as well as a certain proportion (about 40%) of congenital heart defects. Finally the benefits and drawbacks of three main practical applications of folic acid/multivitamin treatment such as (i) dietary intake; (ii) periconceptional supplementation; and (iii) flour fortification are discussed. The conclusion arrived at is indeed confirmation of Benjamin Franklin's statement: "An ounce of prevention is better than a pound of care".

Prenatal folic acid and risk of asthma in children: a systematic review and meta-analysis

BACKGROUND

Childhood asthma has become a critical public health problem because of its high morbidity and increasing prevalence. The impact of nutrition and other exposures during pregnancy on long-term health and development of children has been of increasing interest.

OBJECTIVE

We performed a systematic review and meta-analysis of the association of folate and folic acid intake during pregnancy and risk of asthma and other allergic outcomes in children.

DESIGN

We performed a systematic search of 8 electronic databases for articles that examined the association between prenatal folate or folic acid exposure and risk of asthma and other allergic outcomes (eg, allergy, eczema, and atopic dermatitis) in childhood. We performed a meta-analysis by using a random-effects model to derive a summary risk estimate of studies with similar exposure timing, exposure assessment, and outcomes.

RESULTS

Our meta-analysis provided no evidence of an association between maternal folic acid supplement use (compared with no use) in the prepregnancy period through the first trimester and asthma in childhood (summary risk estimate: 1.01; 95% CI: 0.78, 1.30). Because of substantial heterogeneity in exposures and outcomes, it was not possible to generate summary measures for other folate indicators (eg, blood folate concentrations) and asthma or allergy-related outcomes; however, the preponderance of primary risk estimates was not elevated.

CONCLUSIONS

Our findings do not support an association between periconceptional folic acid supplementation and increased risk of asthma in children. However, because of the limited number and types of studies in the literature, additional research is needed.

Prevention of neural tube defects by nucleotide precursors in the curly tail mouse

Evaluation of: Leung KY, De Castro SC, Savery D et al. Nucleotide precursors prevent folic acid-resistant neural tube defects in the mouse. Brain 136(Pt 9), 2836–2841 (2013). In this study, the authors examined the effects of treating curly tail mutant mice, a folate-resistant mouse model, with specific combinations of pyrimidine and purine nucleotide precursors in an effort to prevent neural tube defects. These investigators found that the prevalence of neural tube defects in the group treated with combinations of thymidine and purine nucleotide precursors was significantly lower than that observed in the control groups. Before combination of nucleotide precursors can be used as a new neural tube defect intervention strategy, the beneficial effects, the side effects, as well as other physiological consequences have to be carefully evaluated and compared with other folate-resistant mice and, ultimately, investigated in human cohorts.

Neural tube defects in Malaysia: data from the Malaysian National Neonatal Registry

This study aimed to determine the prevalence and early outcome of neural tube defects (NTDs) in Malaysia. This prospective study included all neonates with NTDs (spina bifida, anencephaly, encephalocoele) born in 2009 in 32 Malaysian hospitals in the Malaysian National Neonatal Network. The prevalence of NTDs was 0.42 per 1000 live births, being highest among the indigenous people of Sarawak (1.09 per 1000 live births) and lowest among Malaysians of Chinese descent (0.09 per 1000 live births). The most common type of NTDs was anencephaly (0.19 per 1000 live births), followed by spina bifida (0.11 per 1000 live births) and encephalocoele (0.07 per 1000 live births). Majority of the infants with anencephaly (94.5%, n = 51), 45.8% (n = 11) with encephalocoele and 9.5% (n = 4) with spina bifida died. The median duration of hospital stay was 4 (range: 0-161) days.

CONCLUSION

NTDs were common in Malaysia. Mortality was high. Long-term monitoring of NTD prevalence following folic fortification of food is recommended.

Neural tube defects, folic acid and methylation

Neural tube defects (NTDs) are common complex congenital malformations resulting from failure of the neural tube closure during embryogenesis. It is established that folic acid supplementation decreases the prevalence of NTDs, which has led to national public health policies regarding folic acid. To date, animal studies have not provided sufficient information to establish the metabolic and/or genomic mechanism(s) underlying human folic acid responsiveness in NTDs. However, several lines of evidence suggest that not only folates but also choline, B12 and methylation metabolisms are involved in NTDs. Decreased B12 vitamin and increased total choline or homocysteine in maternal blood have been shown to be associated with increased NTDs risk. Several polymorphisms of genes involved in these pathways have also been implicated in risk of development of NTDs. This raises the question whether supplementation with B12 vitamin, betaine or other methylation donors in addition to folic acid periconceptional supplementation will further reduce NTD risk. The objective of this article is to review the role of methylation metabolism in the onset of neural tube defects.

Six paths for the future of social epidemiology

Social epidemiology is now an accepted part of the academic intellectual landscape. However, in many ways, social epidemiology also runs the risk of losing the identity that distinguished it as a field during its emergence. In the present article, we scan the strengths of social epidemiology to imagine paths forward that will make the field distinct and useful to the understanding of population health in future. We suggest 6 paths to such a future, each emerging from promising research trends in the field in which social epidemiologists can, and should, lead in coming years. Each of these paths contributes to the formation of distinct capacities that social epidemiologists can claim and use to elaborate or fill in gaps in the already strong history of social epidemiology. They present an opportunity for the field to build on its strengths and move forward while leading in new and critical areas in population health.

Genetic studies of myelomeningocele

INTRODUCTION

Myelomeningocele is one of the major congenital malformations involving the central nervous system. It is caused by a disruption of the neural tube closure, which is completed at 3-4 weeks of gestation.

DISCUSSION

Multidisciplinary approach is necessary to treat and support this malformation which is a huge burden to the patient, family, and the society. This is a characteristic anomaly that it is known that taking folic acid during the periconceptional period, it is possible to reduce the risk of having a neural tube defect (NTD). Although folate fortification had dramatically reduced the incidence, it was not possible to diminish the risk. To date, many studies have been conducted focusing on candidate genes related to folate and glucose metabolism. We will describe a brief review of genetic etiology of candidate genes of metabolic pathways of folate and glucose, animal models of NTDs, and finally recent studies of microRNA.

Prevention of myelomeningocele: African perspectives

BACKGROUND

The prevention of neural tube defects (NTDs) is now an issue of major public health concern. Myelomeningocele, the most common NTD, often results in severe disabilities and may be life threatening. In Africa, there is little awareness of the NTDs, and most African countries lag behind in the global efforts at preventing them.

PURPOSE

Following a review of global literature, we discuss the burden of myelomeningocele on the society and the current state of its prevention with an emphasis on Africa within the global context. The realization that folate supplementation reduces the occurrence of NTDs by as much as 85 % offers an opportunity to promote global reduction in the incidence of NTDs through (1) effective folate supplementation strategies combined with (2) secondary prevention using prenatal detection and termination of NTD pregnancies within respective national legal frameworks. We call attention to the poor state of understanding of NTDs in Africa and the alarming rarity of policies to prevent the condition in the continent.

CONCLUSIONS

The understanding of the contributions of folate deficiency to the causation of NTDs has enabled appropriate, though still inadequate, preventive measures to be taken in several countries. We call on African governments and the international community to rapidly promote policies aimed at making fortification of wheat (and or other substitute staple foods) with folic acid universally available.

Maternal body mass index and the association between folic acid supplements and neural tube defects

AIM

To study the influence of maternal body mass index (BMI) on the association between folic acid supplementation and neural tube defects (NTDs) risk in offspring.

METHODS

A hospital-based, case-control study was conducted between 2006 and 2008 on 459 mothers with NTDs-affected births and 459 mothers without NTDs-affected births. Logistic regression models examined the associations between folic acid supplementation and the NTDs risk in offspring for all mothers, underweight/normal weight mothers (BMI<24.0) and overweight/obese mothers (BMI ≥24.0). The effects were evaluated by adjusted odds ratio (AOR) and 95% confidence intervals (CIs) with SAS 9.1.3 software.

RESULTS

The overall AOR for periconceptional folic acid supplementation was 0.315 (95% CI = 0.172-0.577) when compared with no supplements. Stratified by maternal BMI, the AOR for periconceptional folic acid supplementation in overweight/obese mothers was greater than in underweight/normal weight mothers (0.646 vs. 0.208). The AOR for folic acid supplementation within 3 months before conception was 0.711 (95% CI = 0.323-1.563) in all mothers. Stratified by maternal BMI, the AOR for folic acid supplementation within 3 months before conception in overweight/obese mothers was greater than in underweight/normal weight mothers (0.658 vs. 0.527).

CONCLUSION

The association between folic acid supplementation and the reduced NTDs risk was weaker in overweight/obese mothers (BMI ≥24.0) than in underweight/normal weight mothers (BMI <24.0).

The impact of folic acid intake on the association among diabetes mellitus, obesity, and spina bifida

OBJECTIVE

The purpose of this study was to investigate the relationship between spina bifida and 2 established risk factors (pregestational diabetes mellitus and obesity) in both the presence and absence of the recommended daily folic acid intake in the periconceptional period.

STUDY DESIGN

Cases of spina bifida (n = 1154) and control subjects (n = 9439) from the Slone Epidemiology Center Birth Defects Study (1976-2011) were included. Information on preexisting diabetes mellitus (collected 1976-2011) and obesity (collected 1993-2011), defined as a body mass index of ≥30 kg/m(2), was collected through interviews that were conducted within 6 months of delivery. Periconceptional folic acid intake was calculated with both dietary and supplement information. Mothers were classified as consuming more or less than 400 μg/day of folic acid; food folate was included at a 30% discount for its lower bioavailability. Logistic regression models that were adjusted for maternal age, race, education, and study site were used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the joint effects of low folic acid intake coupled with diabetes mellitus or obesity.

RESULTS

Case mothers were more likely to have diabetes mellitus or be obese (0.7% and 19.0%, respectively) than control mothers (0.4% and 10.8%, respectively). The joint effect of diabetes mellitus and lower folic acid intake on spina bifida was larger (aOR, 3.95; 95% CI, 1.56-10.00) than that of diabetes mellitus and higher folic acid intake (aOR, 1.31; 95% CI, 0.17-10.30). Folic acid intake made little difference on the association between obesity and spina bifida.

CONCLUSION

Our findings suggest that folic acid further attenuates, although does not eliminate, the risk of spina bifida that is associated with diabetes mellitus than the risk with obesity.

Risk of spina bifida and maternal cigarette, alcohol, and coffee use during the first month of pregnancy

This study was conducted to assess the association between the risks of spina bifida (SB) in relation to cigarette, alcohol, and caffeine consumption by women during the first month of pregnancy. Between 1988–2012, this multi-center case-control study interviewed mothers of 776 SB cases and 8,756 controls about pregnancy events and exposures. We evaluated cigarette smoking, frequency of alcohol drinking, and caffeine intake during the first lunar month of pregnancy in relation to SB risk. Logistic regression models were used to calculate adjusted odds ratios and 95% confidence intervals. Levels of cigarette smoking (1–9 and ≥10/day), alcohol intake (average ≥4 drinks/day) and caffeine intake (<1, 1, and ≥2 cups/day) were not likely to be associated with increased risk of SB. Further, results were similar among women who ingested less than the recommended amount of folic acid (400 μg/day).

Trimethoprim use in early pregnancy and the risk of miscarriage: a register-based nationwide cohort study

The antibiotic trimethoprim acts as a folate antagonist. Since trophoblasts are very sensitive to drugs that interfere with the folic acid cycle and thereby inhibit DNA synthesis, use of trimethoprim during the first trimester could be associated with miscarriage. A nationwide cohort study including all women in Denmark with a registered pregnancy between 1997 and 2005 was conducted. We used nationwide registers to identify all women giving birth, having a record of miscarriage or induced abortion. Data on exposure to trimethoprim were obtained from the National Prescription Register. Cox proportional hazard regression analysis with exposure to trimethoprim as a time-dependent variable was used to estimate the risk of miscarriage. The adjusted hazard ratio of having a miscarriage after exposure to trimethoprim in the first trimester compared to non-exposure was 2∙04 (95% confidence interval 1∙43-2∙91). Our results indicate that trimethoprim exposure in the first trimester is associated with a doubling of the hazard of miscarriage.

The influence of maternal prenatal and early childhood nutrition and maternal prenatal stress on offspring immune system development and neurodevelopmental disorders

The developing immune system and central nervous system in the fetus and child are extremely sensitive to both exogenous and endogenous signals. Early immune system programming, leading to changes that can persist over the life course, has been suggested, and other evidence suggests that immune dysregulation in the early developing brain may play a role in neurodevelopmental disorders such as autism spectrum disorder and schizophrenia. The timing of immune dysregulation with respect to gestational age and neurologic development of the fetus may shape the elicited response. This creates a possible sensitive window of programming or vulnerability. This review will explore the effects of maternal prenatal and infant nutritional status (from conception until early childhood) as well as maternal prenatal stress and anxiety on early programming of immune function, and how this might influence neurodevelopment. We will describe fetal immune system development and maternal-fetal immune interactions to provide a better context for understanding the influence of nutrition and stress on the immune system. Finally, we will discuss the implications for prevention of neurodevelopmental disorders, with a focus on nutrition. Although certain micronutrient supplements have shown to both reduce the risk of neurodevelopmental disorders and enhance fetal immune development, we do not know whether their impact on immune development contributes to the preventive effect on neurodevelopmental disorders. Future studies are needed to elucidate this relationship, which may contribute to a better understanding of preventative mechanisms. Integrating studies of neurodevelopmental disorders and prenatal exposures with the simultaneous evaluation of neural and immune systems will shed light on mechanisms that underlie individual vulnerability or resilience to neurodevelopmental disorders and ultimately contribute to the development of primary preventions and early interventions.

Neural tube defects: recent advances, unsolved questions, and controversies

Neural tube defects are severe congenital malformations affecting around one in every 1000 pregnancies. An innovation in clinical management has come from the finding that closure of open spina bifida lesions in utero can diminish neurological dysfunction in children. Primary prevention with folic acid has been enhanced through introduction of mandatory food fortification in some countries, although not yet in the UK. Genetic predisposition accounts for most of the risk of neural tube defects, and genes that regulate folate one-carbon metabolism and planar cell polarity have been strongly implicated. The sequence of human neural tube closure events remains controversial, but studies of mouse models of neural tube defects show that anencephaly, open spina bifida, and craniorachischisis result from failure of primary neurulation, whereas skin-covered spinal dysraphism results from defective secondary neurulation. Other malformations, such as encephalocele, are likely to be postneurulation disorders.

The association between periconceptional folic acid supplementation and congenital heart defects: a case-control study in China

OBJECTIVE

This study aims to evaluate the association between folic acid (FA) supplementation and congenital heart defects (CHDs).

METHODS

This hospital-based case-control study initiated in 2010 in China analyzed 358 cases and 422 controls. The adjusted odds ratio (AOR) calculated using a logistic model was used to assess the association between FA supplementation and CHDs.

RESULTS

Compared with a mother who reported no FA supplementation, mothers who reported FA supplementation were less likely to have offspring with isolated CHD(s) (AOR=0.52, 0.34-0.78) and multiple complex conditions (AOR=0.27, 0.14-0.55). However, mothers who reported FA supplementation for less than 1 month regardless of the start time of supplementation, did not have a significantly lower risk of having an offspring with isolated or multiple complex conditions. Mothers who reported FA supplementation for ≧3 months beginning before conception had a significantly lower risk of having children with isolated CHD(s) (AOR=0.31, 0.18-0.54).

CONCLUSION

FA-supplementation is associated with reduced risk of CHDs. The earlier FA supplementation begins before pregnancy and the longer supplementation lasts, the lower the risk of CHDs is.