Neural Tube Defects Cases Research Articles

Low folate concentration impacts mismatch repair deficiency in neural tube defects.

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

Folate supplementation for prevention of congenital heart defects and low birth weight: an update.

Women planning a pregnancy and pregnant women in the first trimester are recommended to use folate-containing supplements in order to prevent neural tube defects. The prevention of many cases of neural tube defects with folic acid is evident from meta-analysis, randomized controlled trials (RCTs), observational studies in humans and experimental evidence in animals. However, folate supplementation in pregnant women or a higher maternal folate status has been shown to be protective against other adverse birth outcomes such as congenital heart defects, low birth weight, and preterm birth. Additionally, infants and children with congenital heart defects often show disorders in folate metabolism (low folate, higher homocysteine, or low vitamin B12). Maternal genotype for several folate metabolizing genes has shown associations with the risk of having a child with congenital heart defect. There is some evidence that folate supplementation could have differential effects on sub-types of congenital heart defects, but it is not clear whether the prevention time window is the same as for neural tube defects. Some studies proposed a high dose of folic acid (in mg/d) to prevent congenital heart defects in women with a high global risk (such as those with diabetes or obesity). There are currently no RCTs to support that doses of folic acid in mg range are more effective than the currently recommended 400-800 µg/d taken at least 2-3 months before conception until the end of the first trimester.

Role of Congenital Cytomegalovirus Infection and Protein 53 in Neural tube Defect

Background: Neural tube defects (NTDs) are the greatest shared severely disabling birth defects, they resulted from compound and many etiologies in which both hereditary, life style and ecological factors appear to be convoluted. Objective: To study the role congenital cytomegalovirus and the biomarker Protein 53 (p 53) in pathogenesis of neural tube defects. Patients and Methods: This is a cross sectional comparative study done on 47 mothers of different age group and their babies who have NTD and 47 mothers with their healthy babies at AL-Batool Teaching Hospital/ Diyala/ Iraq from Sept 2017 to May 2018. Rapid serological test to detect anti- CMV IgG and IgM Abs for all case and control groups and their mothers, together with ELISA test to detect P53. The statistical analysis of data was achieved by using SPSS V.20. Results: There was high rate of anti- CMV IgG Abs in NTD cases and their mothers ( n= 10,21.3%, p value= 0.08), out of them, one case had positive anti-IgM Abs together with his mother, whereas in control group, anti CMV IgG was positive in 4(8.5%)in both mothers and their healthy babies with no anti IgM detected. P53 titer is higher to a significant level ( p<0.05) in the mother and their NTD affected baby than control groups ( corresponding babies and mothers). Conclusion: CMV virus might be an important cause of NTD and p53 is a likely to be involved in pathogenesis of NTD.

Is There a Safety Signal for Dolutegravir and Integrase Inhibitors During Pregnancy?

Dolutegravir, an integrase strand transfer inhibitor (InSTI), is a major antiretroviral agent for HIV infection. Its use is promising, especially in low- and middle-income countries, because of a high resistance barrier and a good safety profile. Very recently, a World Health Organization safety signal has been raised regarding neural tube defects after the first-trimester exposure. Furthermore, to date, the experience is limited regarding the use of the other InSTI drugs (raltegravir and elvitegravir) during pregnancy. Our objective is to analyze the safety of InSTI drugs in pregnant women. Nation-wide database cohort analysis. We evaluated the risk of major birth defects according to EUROCAT classification in pregnant women, which had had a first-trimester exposure to dolutegravir, raltegravir, or elvitegravir. We found a major birth defect rate of 1.9% in the general population between 2012 and 2016. As InSTI drugs are not used as first-line therapy in pregnant women, we found a very low exposure in this population. Among 49, 240, and 70 pregnancy outcomes exposed to dolutegravir, raltegravir, and elvitegravir, respectively, during the first trimester, there were 2, 3, and 1 major birth defects, respectively. There was no case of neural tube defect. Drug exposure to InSTI is limited in our nation-wide database. Nevertheless, our data do not support a pharmacovigilance signal on neural tube defects in women exposed to dolutegravir, raltegravir or elvitegravir during pregnancy. Owing to a small number of pregnancy outcomes, these results need to be confirmed with further studies.

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

Neural tube defects (NTDs) are the most common severe birth defects with complex etiologies. Previous studies conducted on animals have suggested that the Grhl3 gene is essential for closure of the spinal neural tube, but little evidence from human studies on the variants of GRHL3 gene has been provided, especially the common genetic variants. To investigate the relationship between common genetic variants of GRHL3 and the risk for NTDs, we performed a case-control study and a case-parent triad/control study. Fast-target enrichment sequencing was performed to screen exon regions from 503 NTD cases, and three tag SNPs (single nucleotide polymorphisms, including rs12030057, rs2486668, and rs545809) were selected according to the sequencing results. Then, Sequenom MassARRAY genotyping was performed in 757 case parents and 519 controls to obtain genotype information of the target variant sites among all NTD triads and controls. The genotype distributions of all SNPs were in accordance with Hardy-Weinberg Equilibrium (HWE) in the control population. In the case-control study, significant associations were found between C27G genetic variants on rs2486668 and risk for spina bifida and encephalocele, respectively, under different genetic models. Consistently, in the case-parent triad/control study, GG genotype on rs2486668 was associated with increased risk for spina bifida, with a RR of 2.15 (95% CI: 1.20-3.83). However, no parent-of-origin effect was found for any tag SNPs. The GRHL3 C67G missense variant may increase the risk for spina bifida and encephalocele phenotypes.

Decreased global DNA hydroxymethylation in neural tube defects: Association with polycyclic aromatic hydrocarbons

ABSTRACT5-Hydroxymethylcytosine (5hmC), a distinct epigenetic marker that plays a role in DNA active demethylation, has been reported to be important for embryonic development and may respond to environmental exposure. No studies have evaluated the association between DNA hydroxymethylation and the risk for fetal neural tube defects (NTDs), with consideration of prenatal exposure to polycyclic aromatic hydrocarbons (PAHs), a risk factor for NTDs.We measured the global levels of 5hmC% in neural tissue from 92 terminated NTD cases and 33 terminated non-malformed fetuses. A lower level of 5hmC% was found in the NTD cases (median [interquartile range]: 0.25 [0.12–0.39]) compared to the controls (0.45 [0.19–1.00]). After adjusting for periconceptional folate supplementation, risk for NTDs increased with decreasing tertiles of 5hmC% (odds ratio: 7.89, 95% confidence interval: 2.32, 26.86, for the lowest tertile relative to the top tertile; pfor trend = 0.002). Linear regression revealed that concentrations of high-molecular-weight PAHs (H_PAHs) in fetal liver tissue were negatively associated with log2-transformed 5hmC%. Superoxide dismutase activity and 5hmC% were positively correlated in fetal neural tissue (rs = 0.64; p < 0.05). A mouse whole-embryo culture model was used for further validation. Decreased levels of 5hmC% and increased levels of reactive oxygen species were found in mouse embryos treated with BaP, a well-studied PAH. Taken together, levels of 5hmC% in fetal neural tissue were inversely associated with the risk for NTDs, and this association may be related to oxidative stress induced by exposure to PAHs.

Exposure-based assessment and economic valuation of adverse birth outcomes and cancer risk due to nitrate in United States drinking water.

BackgroundNitrate ingestion from drinking water has been associated with an increased risk of adverse birth outcomes as well as elevated risk of colorectal cancer and several other cancers. Yet, to date, no studies have attempted to quantify the health and economic impacts due to nitrate in drinking water in the United States. MethodsThis study presents a first-of-its-kind comprehensive assessment of nitrate exposure from drinking water for the entire United States population. This exposure assessment serves as the basis for our analysis of the annual nitrate-attributable disease cases in the United States and the associated economic losses due to medical costs and lost productivity. Additionally, through a meta-analysis of studies on drinking water nitrate and colorectal cancer, we examine the exposure-response relationship for nitrate and cancer risk. ResultsOn the basis of national nitrate occurrence data and relative risk ratios reported in the epidemiology literature, we calculated that annually, 2939 cases of very low birth weight, 1725 cases of very preterm birth, and 41 cases of neural tube defects could be related to nitrate exposure from drinking water. For cancer risk, combining nitrate-specific risk estimates for colorectal, ovarian, thyroid, kidney, and bladder cancers results in a range of 2300 to 12,594 annual nitrate-attributable cancer cases (mean: 6537 estimated cases). For medical expenditures alone, this burden of cancer corresponds to an annual economic cost of 250 million to 1.5 billion U.S. dollars, together with a potential 1.3 to 6.5 billion dollar impact due to lost productivity. With the meta-analysis of eight studies of drinking water nitrate and colorectal cancer, we observed a statistically significant positive association for nitrate exposure and colorectal cancer risk and calculated a one-in-one million cancer risk level of 0.14 mg/L nitrate in drinking water. ConclusionHealth and economic analyses presented here suggest that lowering exposure to nitrate in drinking water could bring economic benefits by alleviating the impacts of nitrate-associated diseases.

Evaluation of folic acid supplementation by concomitant administration of ethinyl estradiol + levonorgestrel in healthy female subjects .

Folic acid supplementation prevents 50-75% of cases of neural tube defects. This study evaluated the folic acid supplementation after oral administration of the ethinyl estradiol 0.02 mg + levonorgestrel 0.10 mg + folic acid 0.4 mg coated tablet as well as its safety and tolerability in healthy female subjects. 36 healthy female subjects received 1 coated tablet of the test product - ethinyl estradiol 0.02mg + levonorgestrel 0.10mg + folic acid 0.4mg for 21days and a placebo coated tablet containing folic acid 0.4mg only on the last 7days of the cycle, in 3 cycles. Blood samples were collected to quantify folate by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The safety was assessed by recording adverse events, monitoring of vital signs, and the evaluation of laboratory tests and ECG. The mean whole blood level of folic acid at baseline (1st day of 1st cycle) was 42.7±22.2ng/mL, while on the 28th day of the 3rd cycle it was 47.6±20.1ng/mL, with a variation of 11.32%. The subjects tolerated the clinical protocol well and reported no clinically significant adverse effects. Oral contraceptives may be a good vehicle for folate supplementation in women of reproductive age.

Exome sequencing of cases with neural tube defects identifies candidate genes involved in one-carbon/vitamin B12 metabolisms and Sonic Hedgehog pathway.

Neural tube defects (NTD) result from complex mechanisms between genes, nutrition and environment. The identification of genetic predictors by genome exome sequencing and their influence on genome methylation need further consideration. Gene variants related to 1-CM metabolism (1-CM) could influence the methylation of genes involved in neural tube embryogenesis through impaired synthesis of S-adenosyl methionine. We performed exome sequencing of 6116 genes referenced in OMIM and NTD risk and genome-wide methylation in 23 NTD cases. We replicated the most significant associations in 81 other cases. The analysis of exome sequencing identified one gene of 1-CM, LRP2, and one gene of Sonic Hedgehog (SHH), GLI3, in the 23 NTD cases. The analysis restricted to genes of 1-CM and neural tube embryogenesis identified five gene predictors of 1-CM (LRP2, rs137983840; MMAA, rs148142853; TCN2, rs35838082; FPGS, rs41306702; BHMT, rs763726268) and two of SHH (GLI3, rs35364414; MKS1, rs151023718). We replicated the association of TCN2, BHMT and GLI3 with NTD risk in the 81 cases. We found a significant hemimethylation of CFAP46 that may influence SHH activation in one case, who carried risk alleles in BHMT, LRP2, MMAA and GLI3. In conclusion, we identified new candidate genes and rare variants that highlight an interacting influence of genes involved in SHH and 1-CM in the puzzle of genetic components of NTD risk.

Casp8 hypomethylation and neural tube defects in association with polycyclic aromatic hydrocarbon exposure

BackgroundEpidemiological studies have found that prenatal exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with increased risk for neural tube defects (NTDs). Aberrant DNA methylation, excessive apoptosis, and oxidative stress have been implied as the mechanism underlying the association between PAH exposure and NTDs, respectively. However, the role of DNA methylation aberration of apoptotic initiator CASP8 (caspase-8, apoptosis-related cysteine peptidase) in the formation of NTDs in association with PAH exposure is not known. By combining a case–control study and mouse model, we aimed to explore the full spectrum of the links from PAH exposure, oxidative stress, CASP8 methylation change, caspase-8 activation, apoptosis, to NTD formation.ResultsHypomethylation of CASP8 promoter was noticed in the microarray profiled by Infinium HumanMethylation450 BeadChip using neural tissues from 10 terminated NTD fetuses and 8 terminated non-malformed fetuses (14 CpG sites, with β difference ranging between 8.8 and 26.3%), and was validated in a larger case–control sample performed with neural tissues from 80 NTD cases and 32 non-malformed fetuses, using the Sequenom MassARRAY system (7 CpG sites). Hypomethylation of CASP8 was a risk factor for NTDs (aOR = 1.11; 95% CI, 1.05–1.17) based on the logistic regression model. According to Pearson’s correlation, methylation levels of CASP8 were inversely correlated with PAH concentrations in maternal serum and with oxidative stress markers in fetal neural tissues (p < 0.05). In the animal study, increased NTD rates (13.5% frequency), Casp8 hypomethylation, caspase-8 upregulation, increased caspase-8 cleavage, and excessive apoptosis were found in mouse embryos cultured with benz(a)pyrene (BaP) in vitro. Antioxidant N-acetyl-L-cysteine (NAC) and BaP co-treatment attenuated the changes found in BaP treatment group.ConclusionsHypomethylation of Casp8 promoter is associated with the formation of NTDs, and Casp8 hypomethylation may be induced by oxidative stress that resulted from exposure to PAHs.

A functional indel polymorphism rs34396413 in TFAP2A intron-5 significantly increases female encephalocele risk in Han Chinese population.

Transcription factor AP-2 alpha (TFAP2A) is an important transcriptional factor involved in various aspects of embryo development including neural tube closure. Tfap2a deficiency led to the failure of cranial neural-tube closure in mice and other model organisms. However, it remains largely unknown about the relationship between TFAP2A variants and human cranial neural tube defects (NTDs). The aim of this study was to find the association between TFAP2A intronic SNP rs3439413 and NTDs and to explore its function. We found an indel polymorphism rs3439413 in TFAP2A intron-5 from our previous target sequencing project. In this study, we validate its association with human NTDs in Shanxi group containing 266 NTD cases and 295 matched controls. Then, we investigated its function on transcriptional activity by dual-luciferase assays and EMSA. The minor allele of rs34396413 significantly increased the risk of NTD in a Han Chinese population of Shanxi Province (P = 0.0082, OR = 1.45, 95%CI = 1.10-1.90), especially the risk of encephalocele for female (P = 0.0064, OR = 2.46, 95%CI = 1.22-4.94). Functional analysis revealed the minor allele of rs34396413 decreases transcriptional activity and attenuates transcription factor binding affinity. We have demonstrated that the minor allele of rs34396413 was a risk factor of NTD in the Shanxi group, providing new insight into the study of NTD etiology.

Evaluation of Neural Tube Defects (NTDs) After Exposure to Raltegravir During Pregnancy.

Objective:To evaluate the risk of neural tube defects (NTDs) after exposure to raltegravir during pregnancy.Methods:Exposures to raltegravir during pregnancy reported cumulatively through May 31, 2018, to the company safety database were reviewed to identify cases of NTDs. This database includes all reports of pregnancy from Merck-sponsored clinical trials, spontaneous postmarketing reports, and non-interventional data sources, including the Antiretroviral Pregnancy Registry (APR). Reports were classified as prospective (before knowledge of pregnancy outcome) or retrospective (after knowledge of pregnancy outcome). We also reviewed data from 2 ongoing pregnancy cohorts.Results:A total of 2426 pregnancies with reported outcomes were identified among women exposed to raltegravir: 1238 from the Merck database and 1188 from United Kingdom/Ireland and French pregnancy cohorts. Among all 2426 reports, 1991 were prospective. No cases of NTDs were identified among the prospective pregnancy reports, of which 767 were first trimester, including 456 in the periconception period (at or within 28 days after conception). Among the 435 retrospective reports, 3 NTD cases per APR criteria were identified (anencephaly, and 2 meningomyelocele), of which only one (meningomyelocele) was among exposures in the periconception period. Given the inherent limitations and bias of retrospective reports, it is not appropriate to calculate an incidence rate.Conclusions:Prospectively collected pregnancy outcome data do not suggest an association between raltegravir exposure in the periconception period and NTDs. The current data support the updated DHHS and EACS treatment guidelines for use of raltegravir as a preferred integrase inhibitor in all stages of pregnancy.

A Multicenter Analysis of Elvitegravir Use During Pregnancy on HIV Viral Suppression and Perinatal Outcomes

BackgroundThere is a knowledge gap on the clinical use of elvitegravir (EVG) during pregnancy and maternal viral suppression. Our objective was to evaluate the effects of EVG use in pregnancy on rates of HIV virologic suppression and perinatal outcomes.MethodsWe conducted a retrospective, multicenter study of pregnant women living with HIV (WLHIV) who used EVG-containing antiretroviral therapy (ART) between January 2014 and March 2017 at 9 tertiary care centers in the United States. WLHIV were included if they took EVG at any time during pregnancy. We described the characteristics of the WLHIV using EVG during the study period and evaluated the rates of HIV suppression and perinatal outcomes.ResultsAmong 134 pregnant WLHIV who received EVG at any time during pregnancy, viral suppression at delivery (HIV-1 RNA < 40 copies/mL) occurred in 81.3%. In WLHIV who initiated EVG before pregnancy and continued through delivery (n = 68), the rate of viral suppression at delivery was 88.2%. The average gestational age at the time of delivery was 37 weeks 6 days, and the overall rate of preterm birth was 20%. No cases of open neural tube defects were noted in women on EVG at the time of conception (n = 82). The perinatal HIV transmission rate was 0.8%.ConclusionsEVG use was associated with high sustained levels of HIV suppression during pregnancy and a low rate of perinatal HIV transmission.

Association of maternal chronic arsenic exposure with the risk of neural tube defects in Northern China

Numerous animal studies have shown that high arsenic exposure can induce neural tube defect (NTD) formation. However, epidemiological evidence related to this finding is scarce. The key objective of our study is to evaluate whether maternal arsenic exposure is associated with NTD risk in Northern China. Our case–control study was conducted in 11 countries or cities in Shanxi and Hebei provinces during 2003–2007. A total of 774 mothers were included as participants: 511 controls and 263 cases (including 123 with anencephaly, 115 with spina bifida, 18 with encephalocele, and 7 with other NTD subtypes). The arsenic concentration was measured in a specific section of hair that grew from 3 months before to 3 months after conception. We found a higher hair arsenic concentration in the NTD cases with median (inter-quartile range) of 0.093 (0.025–0.387) μg/g hair than that in the controls with a value of 0.082 (0.030–0.414) μg/g hair. Maternal hair arsenic concentration above its median of the controls was associated with an increased risk of the total NTDs with an adjusted odds ratio (OR) of 1.32 [95% confidence interval (CI): (0.91–1.92)], which was not statistically significant (p = 0.14), although the crude OR without adjusting for the confounders of 1.68 (95% CI: 1.24–2.27; p < 0.001) suggested that hair arsenic is a risk factor of NTDs. There was no dose-response relationship between maternal hair arsenic concentration and the risk of total NTDs. Similar phenomena were found for anencephaly and spina bifida, respectively. Overall, our findings showed that maternal periconceptional arsenic exposure may not significantly contribute to the risk of NTD development in Northern China; other risk factors need to be further examined in future studies.

One-Carbon Cofactor Intake and Risk of Neural Tube Defects Among Women Who Meet Folic Acid Recommendations: A Multicenter Case-Control Study.

We aimed to investigate associations between individual and concurrent (≥2) intakes of one-carbon cofactors vitamins B6 and B12, choline, betaine, and methionine and neural tube defect (NTD) outcomes among mothers meeting the folic acid recommendations. In the Slone Birth Defects Study (case-control design; North America, 1998-2015), mothers of 164 NTD cases and 2,831 nonmalformed controls completed food frequency questionnaires and structured interviews. Estimated intakes of one-carbon cofactors were dichotomized (high vs. low) for all except betaine (low or middle vs. high). We used logistic regression models to estimate odds ratios and 95% confidence intervals adjusted for center, age, and race. The analysis was restricted to mothers with estimated daily total folate intake of ≥400 μg during periconception. Fewer cases, compared with controls, had high intakes for each one-carbon cofactor except betaine, where the starkest contrast occurred in the middle group. Women with concurrent high intakes of B6, B12, choline, and methionine and moderate intake of betaine had approximately half the risk of an NTD-affected pregnancy (odds ratio = 0.49, 95% confidence interval: 0.23, 1.08). These findings suggest that, in the presence of folic acid, one-carbon cofactors-notably when consumed together-might reduce NTD risk. Additional research should inform any changes to clinical recommendations.

Women's periconceptional lowered carbohydrate intake and NTD-affected pregnancy risk in the era of prefortification with folic acid.

A recent study observed women's restricted carbohydrate diet in the year before conception was associated with increased risk of neural tube defect (NTD)-affected pregnancies. That study corresponded to the era of postfortification of folic acid. Because folic acid and carbohydrate measures would derive from similar foods, investigators of that study could not determine whether the increased risk with restricted carbohydrate intake was a consequence of lower folate intake. We extend their novel observation by examining rigorous NTD data prior to folic acid fortification. Data were derived from a population-based case-control study of fetuses and infants with NTDs among 1989-1991 California births. Interviews were conducted with mothers of 449 NTD cases and with mothers of 458 nonmalformed controls. A standard 100-item food frequency questionnaire was used to assess macro- and micronutrient intakes based on reported intakes 3 months before conception. Case mothers were twice as likely to have consumed a low carbohydrate (≤5th percentile intake among controls) diet with a crude odds ratio of 2.0 (95% confidence interval, 1.2-3.4). Adjustment for race/ethnicity, education, alcohol intake, and folic acid use made very little difference on the odds ratio. Adjustment for total energy intake appeared to be the only factor to slightly attenuate the odds ratio. Our findings indicate that the association between low carbohydrate intake and NTD risk may not be wholly a function of low folic acid in the postfortification era. Such a finding offers new clues to pursue for the seemingly folate-insensitive NTDs that continue to occur.

Wound Closure in Large Neural Tube Defects: Role of Rhomboid Flaps.

Background:Large wounds following surgery for neural tube defects are difficult to close; physical wound characteristics such as position and dimension would serve as a guide for their surgical closure.Aim:To study how wound dimension determines the choice between primary and rhomboid flap closure of skin defects following surgery for neural tube defects.Materials And Methods:A retrospective study was carried out on cases of neural tube defects operated in the department of paediatric surgery at a tertiary center for 3 years from January 2015 to December 2017. Data regarding clinical features, location, wound dimensions following surgery, any bony deformity, method of closure used, distance of wound from anus, and postoperative complications were collected and analyzed.Results:A total of 114 cases were operated during this period; 86/114 had primary closure, whereas 28/114 needed rhomboid flap for tension-free cover. Primarily closed wounds had a biphasic distribution of (long axis)/(short axis) ratio (with values either >1.65 or <0.63), whereas those covered by rhomboid flaps had a mean ratio of 1.25 (range, 0.71–1.45). All six cases with bony deformity needed rhomboid flaps. Although all lipomeningomyelocele defects could be primarily closed, all rachischisis needed flap cover. Infected lesions had a mean wound distance of 5.3cm from posterior anal margin.Conclusion:Defect’s position, its size and shape, and any bony deformity determine the choice of closure of postoperative wound. The versatile, safe, and universal rhomboid flap is an aesthetic solution to the large skin defects in patients of neural tube defects.

Maternal folate nutrition and offspring health: evidence and current controversies.

Periconceptional folic acid (FA) is known to have a protective effect in the prevention of neural tube defects (NTD), leading to global recommendations for FA supplementation before and in early pregnancy. Maternal folate throughout pregnancy may have other roles in offspring health, including neurodevelopment and cognitive performance in childhood. Folate is essential for C1 metabolism, a network of pathways involved in several biological processes including nucleotide synthesis, DNA repair and methylation reactions. The evidence reviewed here shows a conclusive role for offspring health of maternal folate nutrition in early pregnancy and probable benefits in later pregnancy. Folate-mediated epigenetic changes in genes related to brain development and function offer a plausible biological basis to link maternal folate with effects in offspring brain, albeit this research is in its infancy. Mandatory FA fortification of food has proven to be highly effective in decreasing NTD cases in populations where it has been implemented, but this policy is controversial owing to concerns related to potential adverse effects of over-exposure to FA. In the absence of population-wide fortification, and given the generally poor compliance with current FA recommendations, optimising folate status of mothers in very early pregnancy for protection against NTD remains challenging. Thus, current policy in the UK, Ireland and elsewhere in Europe for the prevention of NTD (based on periconceptional FA supplementation only), has proven to be largely ineffective. This review addresses the evidence and the controversies that surround this area, as well as identifying the challenges in translating policy into practice.

Periconceptional folic acid supplementation and sex difference in prevention of neural tube defects and their subtypes in China: results from a large prospective cohort study.

BackgroundFolic acid (FA) supplementation is known to prevent neural tube defects (NTDs). We examined whether this preventive effect differs by the sex of the infant.MethodsData were gathered from a large population-based cohort study in China that evaluated the effects of FA supplementation on NTDs. All births at 20 complete gestational weeks, including live births, stillbirths, and pregnancy terminations, and all NTDs, regardless of gestational age, were recorded. In a northern China province, a total of 30,801 singleton live births to women whose use of FA supplements during the first trimester was known at the time were included in the study. The birth prevalence of NTDs was classified by sex, subtype, and maternal FA supplementation. Male to female rate ratios [RR] and their 95% confidence intervals [CI] were calculated.ResultsA total of 106 NTDs cases were recorded. The overall prevalence of NTDs was 2.5‰ among males and 4.4‰ among females; NTDs were less prevalent among males than among females (RR, 0.58; 95% CI, 0.54–0.63). There was a higher prevalence of anencephaly (RR, 0.34; 95% CI, 0.27–0.43) and spina bifida (RR, 0.73; 95% CI, 0.63–0.84) among females. However, FA supplementation led to significantly greater decreases in the rates of anencephaly (4.8‰) and total NTDs (7.6‰) in females than in males (1.6‰ and 2.8‰, respectively).ConclusionsFA supplementation successfully reduces the prevalence of NTDs in both male and female infants, although we found a significantly greater decrease in anencephaly and total NTDs in females than in males. How the protective effects of FA supplementation affect the sexes differently needs to be studied further.

Maternal periconceptional consumption of sprouted potato and risks of neural tube defects and orofacial clefts

BackgroundThe association between maternal consumption of sprouted potato during periconceptional period on the development of neural tube defects (NTDs) or orofacial clefts (OFCs) remains unclear. We aimed to examine the association between maternal consumption of sprouted potatoes during periconceptional period and risks of NTDs or OFCs.MethodsSubjects included 622 NTD cases, 135 OFC cases and 858 nonmalformed controls, were recruited from a case-control study in Shanxi Province of northern China between 2002 and 2007. Information on demographics, maternal sprouted potato consumption, lifestyle behaviors and folic acid supplementation was collected.ResultsConsumption of sprouted potatoes was associated with elevated odds of total NTDs (OR = 2.20; 95% CI, 1.12–4.32) and anencephaly (OR = 2.48; 95% CI, 1.10–5.58); no association for spina bifida or encephalocele. Sprouted potato consumption increased the risk of total OFCs (OR = 3.49; 95% CI, 1.29–9.49) and cleft lip with or without cleft palate (CL ± P) (OR = 4.03; 95% CI, 1.44–11.28).ConclusionMaternal consumption of sprouted potatoes during periconceptional period may increase the risks of NTDs and OFCs. Given that potato is commonly consumed around the world, improper preservation and use should be a matter of concern in respect of the potential teratogenicity.