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

The beneficial effect of folate-enriched egg on the folate and homocysteine levels in rats fed a folate- and choline-deficient diet

We investigated the effects of folate-enriched egg yolk powder on folate and homocysteine levels in plasma and liver of rats fed the folate- and choline-deficient diet to determine bioavailability in vivo. Three-wk-old Wistar rats were fed (1) the pteroylglutamate (PteGlu), (2) the choline, (3) the PteGlu and choline, (4) the folate-enriched egg yolk powder diet for 4 wk after having been fed the folate- and choline-deficient diet. The hepatic folate level in the folate-enriched egg yolk powder group was significantly higher than that in the folate- and choline-deficient or the control groups. The homocysteine concentration in plasma and liver of the folate-enriched egg yolk powder group was significantly lower than that of the folate- and choline-deficient or the PteGlu groups. The S-adenosyl-methionine (SAM)/S-adenosyl-homocysteine (SAH) ratio in the folate-enriched egg yolk powder group was significantly higher than that in the folate- and choline-deficient group. These effects were similar in the PteGlu and choline, but not the PteGlu or the choline groups. These data suggest that the intake of folate-enriched eggs, as well as of both folate and choline, induced the beneficial effects on folate and homocysteine metabolism. Thus, folate-enriched eggs could be used as beneficial source of folate with a high bioavailability.

EE-drospirenone-levomefolate calcium versus EE-drospirenone + folic acid: folate status during 24 weeks of treatment and over 20 weeks following treatment cessation

Background

Adequate folate supplementation in the periconceptional phase is recommended to reduce the risk of neural tube defects. Oral contraceptives may provide a reasonable delivery vehicle for folate supplementation before conception in women of childbearing potential. This study aimed to demonstrate that a fixed-dose combination of an oral contraceptive and levomefolate calcium leads to sustainable improvements in folate status compared with an oral contraceptive + folic acid.

Methods

This was a double-blind, randomized, parallel-group study in which 172 healthy women aged 18–40 years received ethinylestradiol (EE)-drospirenone-levomefolate calcium or EE-drospirenone + folic acid for 24 weeks (invasion phase), and EE-drospirenone for an additional 20 weeks (folate elimination phase). The main objective of the invasion phase was to examine the area under the folate concentration time-curve for plasma and red blood cell (RBC) folate, while the main objective of the elimination phase was to determine the duration of time for which RBC folate concentration remained ≥ 906 nmol/L after cessation of EE-drospirenone-levomefolate calcium.

Results

Mean concentration-time curves for plasma folate, RBC folate, and homocysteine were comparable between treatment groups during both study phases. During the invasion phase, plasma and RBC folate concentrations increased and approached steady-state after about 8 weeks (plasma) or 24 weeks (RBC). After cessation of treatment with levomefolate calcium, folate concentrations decreased slowly. The median time to RBC folate concentrations falling below 906 nmol/L was 10 weeks (95% confidence interval 8–12 weeks) after cessation of EE-drospirenone-levomefolate calcium treatment. Plasma and RBC folate levels remained above baseline values in 41.3% and 89.3% of women, respectively, at the end of the 20-week elimination phase.

Conclusion

Improvements in folate status were comparable between EE-drospirenone-levomefolate calcium and EE-drospirenone + folic acid. Plasma and RBC folate levels remained elevated for several months following cessation of treatment with EE-drospirenone-levomefolate calcium.

Obesity affects short-term folate pharmacokinetics in women of childbearing age

Maternal folate status and body mass index (BMI) are independent risk factors for neural tube defects (NTD). Population-based studies have identified an inverse association between serum folate and BMI, after adjusting for intake. The objective of this intervention study was to compare the relationship between BMI and the short-term pharmacokinetic response to an oral dose of folic acid. Healthy obese (BMI 30.0 kg m(-2); n=16) and normal-weight (BMI 18.5-24.9 kg m(-2); n=16) women of childbearing age (18-35 years) were administered a single oral dose of folic acid (400 μg). Blood samples were collected over a 10-h period to evaluate the serum folate response. Fasting baseline serum folate was lower in the obese group (P=0.005); in contrast, red blood cell folate was higher (P=0.05). Area-under-the-curve for the absorption phase (0-3 h) and peak serum folate concentrations were lower in obese versus normal-weight women (P<0.005). Overall serum folate response (0-10 h) was lower in obese versus normal-weight women (repeated-measures ANOVA, P=0.001). Data suggest body distribution of folate is significantly affected by obesity, and, should pregnancy occur, may reduce the amount of folate available to the developing embryo. These findings provide additional support for a BMI-adjusted folic acid intake recommendation for NTD risk reduction.

Genetic variants in the folate pathway and the risk of neural tube defects: a meta-analysis of the published literature

BACKGROUND

Neural Tube Defects (NTDs) are among the most prevalent and most severe congenital malformations worldwide. Polymorphisms in key genes involving the folate pathway have been reported to be associated with the risk of NTDs. However, the results from these published studies are conflicting. We surveyed the literature (1996-2011) and performed a comprehensive meta-analysis to provide empirical evidence on the association.

METHODS AND FINDINGS

We investigated the effects of 5 genetic variants from 47 study populations, for a total of 85 case-control comparisons MTHFR C677T (42 studies; 4374 cases, 7232 controls), MTHFR A1298C (22 studies; 2602 cases, 4070 controls), MTR A2756G (9 studies; 843 cases, 1006 controls), MTRR A66G (8 studies; 703 cases, 1572 controls), and RFC-1 A80G (4 studies; 1107 cases, 1585 controls). We found a convincing evidence of dominant effects of MTHFR C677T (OR 1.23; 95%CI 1.07-1.42) and suggestive evidence of RFC-1 A80G (OR 1.55; 95%CI 1.24-1.92). However, we found no significant effects of MTHFR A1298C, MTR A2756G, MTRR A66G in risk of NTDs in dominant, recessive or in allelic models.

CONCLUSIONS

Our meta-analysis strongly suggested a significant association of the variant MTHFR C677T and a suggestive association of RFC-1 A80G with increased risk of NTDs. However, other variants involved in folate pathway do not demonstrate any evidence for a significant marginal association on susceptibility to NTDs.

Folic Acid Supplementation During Early Pregnancy and the Risk of Gestational Hypertension and Preeclampsia

Emerging evidence has suggested that folic acid–containing multivitamins may markedly reduce the risk of gestational hypertension or preeclampsia. We examined whether maternal supplementation with folic acid alone during early pregnancy can prevent the occurrence of gestational hypertension and preeclampsia. The data are from a large population-based cohort study established to evaluate the effectiveness of the campaign to prevent neural tube defects with folic acid supplementation in China. We selected participants who were registered in 2 southern provinces, had exact information on folic acid use, and were not affected by chronic hypertension or diabetes mellitus before 20 weeks gestation. A logistic regression model was used to adjust for the effects of the main potential confounders, including age, body mass index, education, occupation, parity, and multiple births. The study size had 99.9% power (α=0.05) to detect a decrease of 10% over the unexposed rate of 9.4% for gestational hypertension. Among the 193 554 women (47.9% took folic acid, 52.1% did not), the overall incidence of gestational hypertension and preeclampsia was 9.5% and 2.5%, respectively. The incidence of gestational hypertension and preeclampsia was 9.7% and 2.5% for women who took folic acid, and 9.4% and 2.4% for women who did not use it. The adjusted risk ratio associated with folic acid use was 1.08 (95% confidence interval, 1.04–1.11) for gestational hypertension and 1.11 (95% confidence interval, 1.04–1.18) for preeclampsia. Our findings suggest that daily consumption of 400 μg folic acid alone during early pregnancy cannot prevent the occurrence of gestational hypertension and preeclampsia.

Food fortification and decline in the prevalence of neural tube defects: does public intervention reduce the socioeconomic gap in prevalence?

OBJECTIVE

A significant decline in the prevalence of neural tube defects (NTD) through food fortification has been reported. Questions remain, however, about the effectiveness of this intervention in reducing the gap in prevalence across socioeconomic status (SES).

STUDY DESIGN

Using health number and through record linkage, children born in Ontario hospitals between 1994 and 2009 were followed for the diagnosis of congenital anomalies. SES quintiles were assigned to each child using census information at the time of birth. Adjusted rates and multivariate models were used to compare trends among children born in different SES groups.

RESULTS

Children born in low SES areas had significantly higher rates of NTDs (RR = 1.25, CI: 1.14-1.37). Prevalence of NTDs among children born in low and high SES areas declined since food fortification began in 1999 although has started rising again since 2006. While the crude decline was greater in low SES areas, after adjustment for maternal age, the slope of decline and SES gap in prevalence rates remained unchanged overtime.

CONCLUSIONS

While food fortification is successful in reducing the prevalence of NTDs, it was not associated with removing the gap between high and low SES groups.

Effects of folic acid supplementation on overall and site-specific cancer incidence during the randomised trials: meta-analyses of data on 50,000 individuals

BACKGROUND

Some countries fortify flour with folic acid to prevent neural tube defects but others do not, partly because of concerns about possible cancer risks. We aimed to assess any effects on site-specific cancer rates in the randomised trials of folic acid supplementation, at doses higher than those from fortification.

METHODS

In these meta-analyses, we sought all trials completed before 2011 that compared folic acid versus placebo, had scheduled treatment duration at least 1 year, included at least 500 participants, and recorded data on cancer incidence. We obtained individual participant datasets that included 49,621 participants in all 13 such trials (ten trials of folic acid for prevention of cardiovascular disease [n=46,969] and three trials in patients with colorectal adenoma [n=2652]). All these trials were evenly randomised. The main outcome was incident cancer (ignoring non-melanoma skin cancer) during the scheduled treatment period (among participants who were still free of cancer). We compared those allocated folic acid with those allocated placebo, and used log-rank analyses to calculate the cancer incidence rate ratio (RR).

FINDINGS

During a weighted average scheduled treatment duration of 5·2 years, allocation to folic acid quadrupled plasma concentrations of folic acid (57·3 nmol/L for the folic acid groups vs 13·5 nmol/L for the placebo groups), but had no significant effect on overall cancer incidence (1904 cancers in the folic acid groups vs 1809 cancers in the placebo groups, RR 1·06, 95% CI 0·99–1·13, p=0·10). There was no trend towards greater effect with longer treatment. There was no significant heterogeneity between the results of the 13 individual trials (p=0·23), or between the two overall results in the cadiovascular prevention trials and the adenoma trials (p=0·13). Moreover, there was no significant effect of folic acid supplementation on the incidence of cancer of the large intestine, prostate, lung, breast, or any other specific site.

INTERPRETATION

Folic acid supplementation does not substantially increase or decrease incidence of site-specific cancer during the first 5 years of treatment. Fortification of flour and other cereal products involves doses of folic acid that are, on average, an order of magnitude smaller than the doses used in these trials.

FUNDING

British Heart Foundation, Medical Research Council, Cancer Research UK, Food Standards Agency.

Prevention of oro-facial clefts in developing world

Oro-facial cleft (OFC) remains a prominent health issue in developed and developing countries alike. It is the commonest craniofacial birth defect in humans. Mounting evidence suggest a polygenic, multifactorial and a list of epigenetic events. Primary prevention of OFC is based on recognition of the etiologic and risk factors. While a number of preventive strategies are in place for OFC in most developed countries of the world, the majority of developing countries are distant from achieving this goal for a number of reasons. Notable among these are a huge knowledge and practice gap in the field of genetics and dearth of accurate data. In addition, improper coordination and absenteeism from antenatal care contributed greatly to this set back. With ongoing efforts aimed at determining the genetics of nonsyndromic OFC in developing countries, researches directed at identifying environmental factors should equally be in place. Pending the outcome of these, implicated environmental and attitudinal risk factors in other populations could serve as preventive template in health education and interventions. Since risk factors vary between populations, definitive and effective preventive strategies and models would vary from place to place and from time to time. Frantic effort directed at identifying specific implicated risk factors in developing countries should include developing and keeping comprehensive national perinatal database and centralization of antenatal care protocol. Additionally, active health education at every level and a focus on developing manpower in the field of genetics should be in place. These would be designed and tailored toward identified, proven, and emerging risk factors.

The continuing challenge of understanding, preventing, and treating neural tube defects

Human birth defects are a major public health burden: The Center for Disease Control estimates that 1 of every 33 United States newborns presents with a birth defect, and worldwide the estimate approaches 6% of all births. Among the most common and debilitating of human birth defects are those affecting the formation of the neural tube, the precursor to the central nervous system. Neural tube defects (NTDs) arise from a complex combination of genetic and environmental interactions. Although substantial advances have been made in the prevention and treatment of these malformations, NTDs remain a substantial public health problem, and we are only now beginning to understand their etiology. Here, we review the process of neural tube development and how defects in this process lead to NTDs, both in humans and in the animal models that serve to inform our understanding of these processes. The insights we are gaining will help generate new intervention strategies to tackle the clinical challenges and to alleviate the personal and societal burdens that accompany these defects.

Association between the methionine synthase A2756G polymorphism and neural tube defect risk: a meta-analysis

Many studies have accessed the association between methionine synthase (MTR) A2756G polymorphism and neural tube defect (NTD). However, the conclusions are inconsistent. Our study aimed to clarify the nature of the genetic risks contributed by this polymorphism for NTD using meta-analysis. We searched electronic literature from the PubMed, EMBASE, and Medline databases, from which 10 articles were selected according to the inclusion criteria. The meta-analysis was conducted in 3 groups, namely, NTD patients, mothers with NTD offspring and fathers with NTD offspring. Pooled odds ratios (ORs) and 95% confidence intervals were used to evaluate the strength of the association and the result was corrected by multiple testing. To sum up, no associations between the MTR A2756G polymorphism and NTD risk were found among the 3 groups in all genetic models. However, as their sample size is not large enough, this result needs further research.

Epidemiology of Twin Births in Southeast China: 1993–2005

Recently, there has been a significant increase in the rate of multiple births in most developed countries. However, few population-based studies have been conducted in China regarding the epidemiology of twin births in recent years. We performed a descriptive analysis of twin births from 1993 to 2005 using data from a population-based perinatal care program in southeast China. The twin birth rate in southeast China was 0.65%, and the twin birth rates from 1993 to 2005 fluctuated between 0.60% and 0.70%. During the three periods of 1993–1996, 1997–2000, and 2001–2005, the twin birth rate increased from 0.57% to 0.71% in urban areas (p = .005) and from 0.59% to 0.68% in mothers who had an education level of high school or higher (p = .046). After 2000, the twin birth rate of primiparae 30 years of age and older significantly increased from 0.72% to greater than 1.20%. We concluded that the twin birth rates in southeast China from 1993 to 2005 stayed constant in the overall population but increased in certain subgroups of women, presumably due to increased use of fertility treatment and the development of assisted reproductive technology.

Trimethoprim Use prior to Pregnancy and the Risk of Congenital Malformation: A Register-Based Nationwide Cohort Study

Objectives. The aim of the study was to investigate whether the use of the antifolate antibiotic trimethoprim during the 12 weeks before conception was associated with congenital malformations. Methods. We conducted a nationwide register-based cohort study including all Danish women giving birth from 1997 to 2004. All women with at least one prescription of trimethoprim dispensed during the 12 weeks before conception were identified. Results. There was a doubling of congenital malformations in offspring to women exposed to trimethoprim in the 12 weeks before conception. The adjusted odds ratio (OR) of major congenital malformation was 1.87, 95% confidence interval (CI) 1.25–2.81. There was a significant increase in major malformations of the heart (OR = 2.49; 1.18–5.26) and limbs (OR = 2.18; 1.13–4.23). Conclusions. In this study, we found an association between exposure to trimethoprim during the 12 weeks before conception and an increased risk of heart and limb defects.

Association between maternal use of folic acid supplements and risk of autism spectrum disorders in children

IMPORTANCE

Prenatal folic acid supplements reduce the risk of neural tube defects in children, but it has not been determined whether they protect against other neurodevelopmental disorders.

OBJECTIVE

To examine the association between maternal use of prenatal folic acid supplements and subsequent risk of autism spectrum disorders (ASDs) (autistic disorder, Asperger syndrome, pervasive developmental disorder-not otherwise specified [PDD-NOS]) in children.

DESIGN, SETTING, AND PATIENTS

The study sample of 85,176 children was derived from the population-based, prospective Norwegian Mother and Child Cohort Study (MoBa). The children were born in 2002-2008; by the end of follow-up on March 31, 2012, the age range was 3.3 through 10.2 years (mean, 6.4 years). The exposure of primary interest was use of folic acid from 4 weeks before to 8 weeks after the start of pregnancy, defined as the first day of the last menstrual period before conception. Relative risks of ASDs were estimated by odds ratios (ORs) with 95% CIs in a logistic regression analysis. Analyses were adjusted for maternal education level, year of birth, and parity.

MAIN OUTCOME MEASURE

Specialist-confirmed diagnosis of ASDs.

RESULTS

At the end of follow-up, 270 children in the study sample had been diagnosed with ASDs: 114 with autistic disorder, 56 with Asperger syndrome, and 100 with PDD-NOS. In children whose mothers took folic acid, 0.10% (64/61,042) had autistic disorder, compared with 0.21% (50/24,134) in those unexposed to folic acid. The adjusted OR for autistic disorder in children of folic acid users was 0.61 (95% CI, 0.41-0.90). No association was found with Asperger syndrome or PDD-NOS, but power was limited. Similar analyses for prenatal fish oil supplements showed no such association with autistic disorder, even though fish oil use was associated with the same maternal characteristics as folic acid use.

CONCLUSIONS AND RELEVANCE

Use of prenatal folic acid supplements around the time of conception was associated with a lower risk of autistic disorder in the MoBa cohort. Although these findings cannot establish causality, they do support prenatal folic acid supplementation.

Cognition and behavioural development in early childhood: the role of birth weight and postnatal growth

BACKGROUND

We evaluate the relative importance of birth weight and postnatal growth for cognition and behavioural development in 8389 Chinese children, 4-7 years of age. Method Weight was the only size measure available at birth. Weight, height, head circumference and intelligence quotient (IQ) were measured between 4 and 7 years of age. Z-scores of birth weight and postnatal conditional weight gain to 4-7 years, as well as height and head circumference at 4-7 years of age, were the exposure variables. Z-scores of weight at 4-7 years were regressed on birth weight Z-scores, and the residual was used as the measure of postnatal conditional weight gain. The outcomes were child's IQ, measured by the Chinese Wechsler Young Children Scale of Intelligence, as well as internalizing behavioural problems, externalizing behavioural problems and other behavioural problems, evaluated by the Child Behavior Checklist 4-18. Multivariate regressions were conducted to investigate the relationship of birth weight and postnatal growth variables with the outcomes, separately for preterm children and term children.

RESULTS

Both birth weight and postnatal weight gain were associated with IQ among term children; 1 unit increment in Z-score of birth weight (∼450 g) was associated with an increase of 1.60 [Confidence interval (CI): 1.18-2.02; P < 0.001] points in IQ, and 1 unit increment in conditional postnatal weight was associated with an increase of 0.46 (CI: 0.06-0.86; P = 0.02) points in IQ, after adjustment for confounders; similar patterns were observed when Z-scores of postnatal height and head circumference at age 4-7 years were used as alternative measurements of postnatal growth. Effect sizes of relationships with IQ were smaller than 0.1 of a standard deviation in all cases. Neither birth weight nor postnatal growth indicators were associated with behavioural outcomes among term children. In preterm children, neither birth weight nor postnatal growth measures were associated with IQ or behavioural outcomes.

CONCLUSIONS

Both birth weight and postnatal growth were associated with IQ but not behavioural outcomes for Chinese term children aged 4-7 years, but the effect sizes were small. No relation between either birth weight or postnatal growth and cognition or behavioural outcomes was observed among preterm children aged 4-7 years.

The MTHFR C677T Variant is Associated with Responsiveness to Disulfiram Treatment for Cocaine Dependency

OBJECTIVE

Disulfiram is a one of the few pharmacotherapies for cocaine addiction that shows promise. Since disulfiram and cocaine both affect levels of global methylation we hypothesized the MTHFR gene, whose product is involved in supplying methyl groups for DNA and protein methylation, may be associated with responsiveness to disulfiram in cocaine-dependent individuals.

METHODS

Sixty-seven cocaine-dependent patients were stabilized on methadone for 2 weeks and then randomized into disulfiram (250 mg/day, N = 32) and placebo groups (N = 35) for 10 weeks. Patients were genotyped for the MTHFR (rs1801133, also known as C677T) polymorphism and the data was evaluated for association with cocaine-free urines in the disulfiram or placebo groups. Data from patients that completed all 10 weeks of the study (N = 56) were analyzed using repeated measures analysis of variance (ANOVA), corrected for population structure.

RESULTS

The CT or TT MTHFR genotype group (N = 32) dropped from 73 to 52% cocaine-positive urines on disulfiram (p = 0.0001), while the placebo group showed no treatment effect. The CC MTHFR genotype group (N = 24) showed a smaller, but still significant, reduction in cocaine-positive urines on disulfiram compared to placebo; 81-69% (p = 0.007).

CONCLUSION

This study indicates that a patient's MTHFR genotype may be used to identify individuals who might show improved response to disulfiram treatment for cocaine dependence.

CLINICAL TRIAL

Pharmacogenetics of Disulfiram for Cocaine, clinicaltrials.gov/ct2/show/NCT00149630, NIDA-18197-2, NCT00149630.

Modeling fortification of corn masa flour with folic acid: the potential impact on exceeding the tolerable upper intake level for folic acid, NHANES 2001-2008

Background

The Institute of Medicine set a tolerable upper intake level (UL) for usual daily total folic acid intake (1,000 µg). Less than 3% of US adults currently exceed the UL.

Objective

The objective of this study was to determine if folic acid fortification of corn masa flour would increase the percentage of the US population who exceed the UL.

Design

We used dietary intake data from NHANES 2001–2008 to estimate the percentage of adults and children who would exceed the UL if corn masa flour were fortified at 140 µg of folic acid/100 g.

Results

In 2001–2008, 2.5% of the US adult population (aged≥19 years) exceeded the UL, which could increase to 2.6% if fortification of corn masa flour occurred. With corn masa flour fortification, percentage point increases were small and not statistically significant for US adults exceeding the UL regardless of supplement use, sex, race/ethnicity, or age. Children aged 1–8 years, specifically supplement users, were the most likely to exceed their age-specific UL. With fortification of corn masa flour, there were no statistically significant increases in the percentage of US children who were exceeding their age-specific UL, and the percentage point increases were small.

Conclusions

Our results suggest that fortification of corn masa flour would not significantly increase the percentage of individuals who would exceed the UL. Supplement use was the main factor related to exceeding the UL with or without fortification of corn masa flour and within all strata of sex, race/ethnicity, and age group.

Neural tube defects and their significance in clinical dentistry: a mini review

Neural tube defects are common congenital malformations that could be apparent at birth or manifested in later stages of life. Morbidity is high in anencephaly, whereas in spina bifida, there are neurological and motor disorders. These defects deserve paramount importance in clinical dentistry. Latex allergy, dental caries, difficulty in mouth opening, and sitting in a dental chair are common problems. There is a high risk of anaphylactic response during anaesthesia. There could be associated craniosynostosis causing maxillary deficiency, and malformed sella turcica might be seen. An association of the defects has been linked with orofacial clefts and Down syndrome.

Risk factors associated with birth defects at a tertiary care center in Pakistan

Background

Birth defects are defined as those conditions that are substantially determined before or during birth and which are recognizable in early life. They are an important cause of morbidity and mortality in infants. The main objective of the study was to determine the association of certain risk factors with birth defects occurring in pediatric patients seeking care in Civil Hospital, Karachi.

Methods

This was a prospective, cross-sectional study conducted at Department of Pediatrics: Units I, II and III of Civil Hospital Karachi, which is a tertiary care hospital located in the city center. These units provide care to pediatric patients from all over the country, with majority belonging to a low socioeconomic background. All infants with at least one birth defect were approached and their mothers interviewed. Demographics of both the mother and the infant were noted. Questions regarding possible exposure to risk factors were asked. Infants who were not accompanied by their mothers were excluded from the study.

Results

A total of 587 out of 669 infants completed the study successfully. Of these, defects related to urogenital system (19.9%) were the commonest, followed by those related to eye (16.9%), musculoskeletal system (12.9%), body wall defects (12.3%), oral cavity (12.1%), central nervous system (10.9%), gastrointestinal tract (3.2%), cardiovascular system (2.7%) and those related to ear, nose and throat (1.2%).

Conclusion

669(4.1%) out of a total of 16,394 pediatric patients visiting the hospital during our study were identified as having at least one birth defect. The commonest ones were those related to the eye and the urogenital system. The main factors that influence the occurrence can be grouped into maternal, socioeconomic, nutritional and educational.

The impact of spina bifida on caregivers

INTRODUCTION

Neural tube defects (NTDs) are the second most common birth defects. Spina bifida (SB) and anencephaly make up approximately 90% of total NTDs. Given the number of infants born with an NTD each year, anyone who provides unpaid care for the child (especially caregivers) is affected. This literature review explores the humanistic burden on caregivers of people with SB, specifically myelomeningocele.

METHODS

A search using PubMed, PsycINFO, and Embase was performed to find studies from 1976 to 2010. Interpretative phenomenological analysis was performed on qualitative data and relevant extracts from the data were collated to form master themes.

RESULTS

A total of 168 abstracts met the inclusion and exclusion criteria. Of these, 25 articles related to caregivers of individuals with SB. Four master themes emerged: initial diagnosis, living with an individual with SB, social support, and coping. Different aspects of caregivers' lives were found to be affected by caring for a child with SB, including activities of daily living, work impact, time consumption, parental responsibilities, confidence, feelings and emotions, mental health, stress, social impact, psychological adjustment, and relationships.

CONCLUSION

NTDs, such as SB, present a multitude of issues to caregivers. Issues that affect caregivers of individuals with SB must be addressed in order to reduce the considerable burden that SB places on the caregiver. Continued and enhanced support from health services and patient advocacy groups is needed. For example, providing additional information, support, and empathy can help parents prepare themselves for dealing with the needs of a child with SB over their lifetime.

Comprehensive evaluation of Safyral(®) 2012

The incidence of pregnancies affected with neural tube defects (NTDs) has been reduced by food fortification programs and public health campaigns promoting folic acid supplementation, but the incidence of NTDs in the USA has not achieved the full potential reduction expected with adequate periconceptional folate utilization. In seeking new ways to access sexually active women at risk for pregnancy, one option would be to link folic acid supplementation to contraceptive use. Since birth control pills are the most popular method of reversible contraception in the USA, it would seem quite logical to find a way to supplement them. To this end, a very efficient folate, levomefolate calcium salt (metafolin), has been added to drospirenone-containing oral contraceptives in equimolar concentrations to the recommended supplements of folic acid to reduce the risk for pregnancy and to reduce the risk of NTDs in pregnancies that occur while women are taking the pill or shortly after they discontinue its use. This article will focus on the need for such folate supplementation and will summarize the contraceptive and noncontraceptive benefits of the 30 µg EE/3 mg drospirenone pill (Yasmin(®), Bayer Healthcare, NJ, USA) to which has been added 451 metafolin (Safyral(®), Bayer Healthcare). The new information about thromboembolism risks associated with use of drospirenone-containing pills is also discussed.

Oral cleft prevention program (OCPP)

Background

Oral clefts are one of the most common birth defects with significant medical, psychosocial, and economic ramifications. Oral clefts have a complex etiology with genetic and environmental risk factors. There are suggestive results for decreased risks of cleft occurrence and recurrence with folic acid supplements taken at preconception and during pregnancy with a stronger evidence for higher than lower doses in preventing recurrence. Yet previous studies have suffered from considerable design limitations particularly non-randomization into treatment. There is also well-documented effectiveness for folic acid in preventing neural tube defect occurrence at 0.4 mg and recurrence with 4 mg. Given the substantial burden of clefting on the individual and the family and the supportive data for the effectiveness of folic acid supplementation as well as its low cost, a randomized clinical trial of the effectiveness of high versus low dose folic acid for prevention of cleft recurrence is warranted.

Methods/design

This study will assess the effect of 4 mg and 0.4 mg doses of folic acid, taken on a daily basis during preconception and up to 3 months of pregnancy by women who are at risk of having a child with nonsyndromic cleft lip with/without palate (NSCL/P), on the recurrence of NSCL/P. The total sample will include about 6,000 women (that either have NSCL/P or that have at least one child with NSCL/P) randomly assigned to the 4 mg and the 0.4 mg folic acid study groups. The study will also compare the recurrence rates of NSCL/P in the total sample of subjects, as well as the two study groups (4mg, 0.4 mg) to that of a historical control group.

The study has been approved by IRBs (ethics committees) of all involved sites. Results will be disseminated through publications and presentations at scientific meetings.

Discussion

The costs related to oral clefts are high, including long term psychological and socio-economic effects. This study provides an opportunity for huge savings in not only money but the overall quality of life. This may help establish more specific clinical guidelines for oral cleft prevention so that the intervention can be better tailored for at-risk women.

ClinicalTrials.gov Identifier

NCT00397917

Neural tube defects and maternal intake of micronutrients related to one-carbon metabolism or antioxidant activity

BACKGROUND

Maternal nutritional status has been evaluated to clarify its role in development of neural tube defects (NTDs). Maternal folate intake during pregnancy has been closely evaluated for its association with NTDs. The study objective was to examine associations between NTDs and other dietary periconceptional micronutrient intake, particularly nutrients involved in one-carbon metabolism or antioxidant activity.

METHODS

Using data from the National Birth Defects Prevention Study, 1997-2005, logistic regression models were used to estimate the relative risk of NTDs based on maternal micronutrient intake.

RESULTS

Results were stratified according to folic acid supplement use, race/ethnicity, and maternal body mass index. Analyses included 954 cases (300 with anencephaly, 654 with spina bifida) and 6268 controls. Higher intakes of folate, thiamin, betaine, iron, and vitamin A were associated with decreased risk of anencephaly among some ethnic and clinical groups. In some groups, higher intakes of thiamin, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, and retinol were associated with decreased risk of spina bifida.

CONCLUSION

In addition to folic acid, other micronutrients, including thiamin, betaine, riboflavin, vitamin B(6) , vitamin C, vitamin E, niacin, iron, retinol, and vitamin A, may decrease the risk of NTD occurrence. Birth Defects Research (Part A) 2012. © 2012 Wiley Periodicals, Inc.

Effect of folic acid intervention on the change of serum folate level in hypertensive Chinese adults: do methylenetetrahydrofolate reductase and methionine synthase gene polymorphisms affect therapeutic responses?

OBJECTIVES

To assess the influence of individual methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase A2756G polymorphisms on the change of serum folate concentration in response to different dosages and durations of folic acid (FA) supplementation in hypertensive Chinese adults.

METHODS

A total of 480 patients with mild or moderate essential hypertension were randomly assigned to three treatment groups: (a) enalapril only (10 mg, control group); (b) enalapril FA tablet [10 : 0.4 mg (10 mg of enalapril combined with 0.4 mg of FA), low-FA group]; (c) enalapril FA tablet (10 : 0.8 mg, high-FA group), once daily for 8 weeks. Individual serum folate levels were measured at baseline, and at 4 and 8 weeks posttreatment.

RESULTS

After 4 or 8 weeks of treatment, increases in serum folate were seen across all genotypes and FA dosage groups. However, compared with patients with 677CC genotype, those with CT or TT genotype in the low-FA group and TT genotype in the high-FA group still had significantly lower folate concentrations, particularly women. In the low-FA group, patients with CT or TT genotype showed an attenuated response compared with those with CC genotype (median ratio of folate at week 8 to that at baseline: CC,1.953 vs. CT,1.755 or TT,1.637, P<0.01 for both). Such an attenuated response was not observed in the high-FA group. Yet, only in the high-FA group did serum folate appear to reach a plateau after 4 weeks of treatment in all three MTHFR 677 genotypes and the methionine synthase 2756 AG/GG genotype.

CONCLUSION

We demonstrated that MTHFR C677T polymorphisms can not only affect serum folate levels at the baseline and post-FA treatment, but also therapeutic responses to various dosages and durations of FA supplementation.

[Current practice of positive family planning service in the National Institute of Child Health in the last six years]

The aim of positive family planning is to prevent preterm delivery and congenital abnormalities. Using primer prevention models at this time helps to prevent the common disorders which are the leading causes of death. The mission of the National Institute of Child Health is to promote preconceptional health and thus, mother and baby's health. This article introduces the practice of our institute's family planning department and the last six years' experiences.

Maternal Prenatal Nutrition and Health in Grandchildren and Subsequent Generations

This review focuses on how maternal prenatal nutritional states may affect the health of grandchildren and later generations. We first summarize the limited current data in human populations relating to the potential transmission of phenotypes across multiple generations that result from the nutritional experience of a pregnant woman. We then discuss findings from other species, especially mammals, that provide important clues as to whether, and if so how, such transmission could occur in humans. Finally, we consider how studies of human populations could be best designed to detect transmission across multiple generations. We argue that just as epidemiologists embraced a life-course perspective to human health and disease in the twentieth century, we must now seek to better understand how health and disease could be shaped across multiple generations.

Use of folic acid supplements in early pregnancy in relation to maternal plasma levels in week 18 of pregnancy

SCOPE

Birth cohorts typically measure plasma folate in midgestation, but effects of folic acid supplementation are sometimes specific to the periconceptional period. The relationship between midgestation plasma folate and periconceptional supplementation is not known. We compared plasma folate at week 18 of gestation with self-report use of supplements comtaining folic acid from before pregnancy to week 17 of gestation.

METHODS AND RESULTS

The sample comprised 2911 women from The Norwegian Mother and Child Cohort Study. For women reporting continuous supplementation from gestational week -4 to 17 (N = 238), median plasma folate was 15.72 at week 18 (in nmol/L). This was about threefold higher than the median plasma folate of 5.67 for women reporting no supplementation from week -4 to 17 (N = 844), but only slightly higher than the median plasma folate of 13.34 for all women reporting supplementation in weeks 13-17 (N = 1158). Reported supplementation before week 8 was not associated with plasma folate at week 18, in an analysis that adjusted for continued supplementation after week 8.

CONCLUSION

Overall we found a strong and coherent relationship between self-reported folic acid use and plasma folate at week 18. We also found that plasma folate at week 18 did not reflect self-reported supplementation before week 8. For periconceptional supplementation per se, self-report data may offer a better measure.

Maternal B vitamin status in pregnancy week 18 according to reported use of folic acid supplements

SCOPE

Epidemiological studies on the association between pregnancy outcomes and use of periconceptional folic acid are often based on maternal reported intake. Use of folic acid during pregnancy is associated with a higher socioeconomic status known to have an impact on diet quality. We have studied plasma B vitamin status according to reported use of folic acid supplements during the periconceptional period in Norwegian women.

METHODS AND RESULTS

Plasma levels of folate, cobalamin, pyridoxal 5'-phosphate (vitamin B6), riboflavin, and the metabolic markers total homocysteine, methylmalonic acid and 3-hydro-xykynurenine were measured in pregnancy week 18 and related to reported intake of folic acid from 4 weeks prior to conception throughout week 18 in 2911 women from the Norwegian Mother and Child Cohort Study (MoBa) conducted by the Norwegian Institute of Public Health. Being a folic acid user during the periconceptional period was associated with a better socioeconomic status, and a higher intake of several micronutrients, including vitamins, trace-metals, and omega 3 fatty acids. Folic acid users had a significantly better plasma B vitamin status.

CONCLUSION

Epidemiological data based on maternal reported intake of folic acid supplements during pregnancy, should take into account the numerous nutritional implications, in addition to higher blood folate levels, of being a folic acid user.

The fetal origins of the metabolic syndrome: can we intervene?

Epidemiological studies have suggested that metabolic programming begins during fetal life and adverse events in utero are a critical factor in the etiology of chronic diseases and overall health. While the underlying molecular mechanisms linking impaired fetal development to these adult diseases are being elucidated, little is known about how we can intervene early in life to diminish the incidence and severity of these long-term diseases. This paper highlights the latest clinical and pharmaceutical studies addressing how dietary intervention in fetal and neonatal life may be able to prevent aspects of the metabolic syndrome associated with IUGR pregnancies.

Reduced folate carrier A80G polymorphism and susceptibility to neural tube defects: a meta-analysis

The reduced folate carrier (RFC1) plays a crucial role in mediating folate delivery into a variety of cells. RFC1 polymorphism (A80G) has been reported to be associated with increased risk of neural tube defects (NTDs). However, results derived from individually underpowered studies are conflicting. We performed a systematic search of MEDLINE and EMBASE databases and carried out a meta-analysis on the association between RFC1 polymorphism (A80G) and NTDs risk. Overall, a significant correlation between RFC1 A80G polymorphism and NTDs risk was found neither in infants nor in maternal (allele contrast in infants: OR(RE)=1.15, 95% CI: 0.92-1.45; allele contrast in mothers: OR(RE)=1.24, 95% CI: 0.98-1.56). The present meta-analysis failed to support a positive association between RFC1 A80G polymorphism and susceptibility to NTDs. It is important to realize, however, that socio-economic factors, and gene-environment and gene-gene interactions, could have influenced the outcome of our meta-analysis. For this reason, a relationship between the A80G polymorphism and NTD risk cannot be entirely discounted.

Periconceptional folate deficiency and implications in neural tube defects

Nutritional deficiencies are preventable etiological and epigenetic factors causing congenital abnormalities, first cause of infant mortality. Folate deficiency has a well-established teratogenic effect, leading to an increasing risk of neural tube defects. This paper highlights the most recent medical literature about folate deficiency, be it maternal or paternal. It then focuses on associated deficiencies as nutritional deficiencies are multiple and interrelated. Observational and interventional studies have all been consistent with a 50–70% protective effect of adequate women consumption of folates on neural tube defects. Since strategies to modify women's dietary habits and vitamin use have achieved little progress, scientific as well as political effort is mandatory in order to implement global preventive public health strategies aimed at improving the alimentation of women in reproductive age, especially folic acid supplementation. Even with the recent breakthrough of fetal surgery for myelomeningocele, the emphasis should still be on prevention as the best practice rather than treatment of neural tube defects.

Evaluation of common genetic variants in 82 candidate genes as risk factors for neural tube defects

BACKGROUND

Neural tube defects (NTDs) are common birth defects (~1 in 1000 pregnancies in the US and Europe) that have complex origins, including environmental and genetic factors. A low level of maternal folate is one well-established risk factor, with maternal periconceptional folic acid supplementation reducing the occurrence of NTD pregnancies by 50-70%. Gene variants in the folate metabolic pathway (e.g., MTHFR rs1801133 (677 C > T) and MTHFD1 rs2236225 (R653Q)) have been found to increase NTD risk. We hypothesized that variants in additional folate/B12 pathway genes contribute to NTD risk.

METHODS

A tagSNP approach was used to screen common variation in 82 candidate genes selected from the folate/B12 pathway and NTD mouse models. We initially genotyped polymorphisms in 320 Irish triads (NTD cases and their parents), including 301 cases and 341 Irish controls to perform case-control and family based association tests. Significantly associated polymorphisms were genotyped in a secondary set of 250 families that included 229 cases and 658 controls. The combined results for 1441 SNPs were used in a joint analysis to test for case and maternal effects.

RESULTS

Nearly 70 SNPs in 30 genes were found to be associated with NTDs at the p < 0.01 level. The ten strongest association signals (p-value range: 0.0003-0.0023) were found in nine genes (MFTC, CDKN2A, ADA, PEMT, CUBN, GART, DNMT3A, MTHFD1 and T (Brachyury)) and included the known NTD risk factor MTHFD1 R653Q (rs2236225). The single strongest signal was observed in a new candidate, MFTC rs17803441 (OR = 1.61 [1.23-2.08], p = 0.0003 for the minor allele). Though nominally significant, these associations did not remain significant after correction for multiple hypothesis testing.

CONCLUSIONS

To our knowledge, with respect to sample size and scope of evaluation of candidate polymorphisms, this is the largest NTD genetic association study reported to date. The scale of the study and the stringency of correction are likely to have contributed to real associations failing to survive correction. We have produced a ranked list of variants with the strongest association signals. Variants in the highest rank of associations are likely to include true associations and should be high priority candidates for further study of NTD risk.

Impact of folic acid fortification of flour on neural tube defects: a systematic review

Objective

To review the impact of folic acid fortification of flour on the prevalence of neural tube defects (NTD).

Design

Systematic review of the literature on MEDLINE via PubMed, Scopus, OvidSP and LILACS (Latin American and Caribbean Health Sciences Literature) reporting the impact of folic acid fortification of flour on the prevalence of NTD in 2000–2011. Focusing on Santiago of Chile's birth defects registry (1999–2009) and the monitoring of flour fortification, we analysed the prevalence (NTD cases/10 000 births) pre and post flour fortification and the percentile distribution of folic acid content in flour (2005–2009). We explored the potential association between median folic acid in flour (mg/kg) and the prevalence of NTD.

Setting

Chile, Argentina, Brazil, Canada, Costa Rica, Iran, Jordan, South Africa and the USA.

Subjects

Live births and stillbirths.

Results

Twenty-seven studies that met inclusion criteria were evaluated. Costa Rica showed a significant reduction in NTD (∼60 %). Prevalence in Chile decreased from 18·6 to 7·3/10 000 births from 1999 to 2007 and showed a slight increase to 8·5 in 2008–2009, possibly due to changes in fortification limits. When we related the prevalence of NTD with levels of flour fortification, the lowest prevalence was observed at a folic acid level of 1·5 mg/kg.

Conclusions

Fortification of flour with folic acid has had a major impact on NTD in all countries where this has been reported. Chile showed a 55 % reduction in NTD prevalence between 1999 and 2009. There is a need to constantly monitor the levels of flour fortification to maximize benefits and prevent the potential risk of folic acid excess, moreover to be vigilant for any new adverse effects associated with excess.

Effect of women's nutrition before and during early pregnancy on maternal and infant outcomes: a systematic review

Current understanding of biologic processes indicates that women's nutritional status before and during early pregnancy may play an important role in determining early developmental processes and ensuring successful pregnancy outcomes. We conducted a systematic review of the evidence for the impact of maternal nutrition before and during early pregnancy (<12 weeks gestation) on maternal, neonatal and child health outcomes and included 45 articles (nine intervention trials and 32 observational studies) that were identified through PubMed and EMBASE database searches and examining review articles. Intervention trials and observational studies show that periconceptional (<12 weeks gestation) folic acid supplementation significantly reduced the risk of neural tube defects. Observational studies suggest that preconceptional and periconceptional intake of vitamin and mineral supplements is associated with a reduced risk of delivering offspring who are low birthweight and/or small-for-gestational age (SGA) and preterm deliveries (PTD). Some studies report that indicators of maternal prepregnancy size, low stature, underweight and overweight are associated with increased risks of PTD and SGA. The available data indicate the importance of women's nutrition prior to and during the first trimester of pregnancy, but there is a need for well-designed prospective studies and controlled trials in developing country settings that examine relationships with low birthweight, SGA, PTD, stillbirth and maternal and neonatal mortality. The knowledge gaps that need to be addressed include the evaluation of periconceptional interventions such as food supplements, multivitamin-mineral supplements and/or specific micronutrients (iron, zinc, iodine, vitamin B-6 and B-12) as well as the relationship between measures of prepregnancy body size and composition and maternal, neonatal and child health outcomes.

Factors associated with prenatal folic acid and iron supplementation among 21,889 pregnant women in Northern Tanzania: a cross-sectional hospital-based study

Background

Folate and iron deficiency during pregnancy are risk factors for anaemia, preterm delivery, and low birth weight, and may contribute to poor neonatal health and increased maternal mortality. The World Health Organization recommends supplementation of folic acid (FA) and iron for all pregnant women at risk of malnutrition to prevent anaemia. We assessed the use of prenatal folic acid and iron supplementation among women in a geographical area with a high prevalence of anaemia, in relation to socio-demographic, morbidity and health services utilization factors.

Methods

We analysed a cohort of 21,889 women who delivered at Kilimanjaro Christian Medical Centre (KCMC), Moshi, Tanzania, between 1999 and 2008. Logistic regression models were used to describe patterns of reported intake of prenatal FA and iron supplements.

Results

Prenatal intake of FA and iron supplements was reported by 17.2% and 22.3% of pregnant women, respectively. Sixteen percent of women reported intake of both FA and iron. Factors positively associated with FA supplementation were advanced maternal age (OR = 1.17, 1.02-1.34), unknown HIV status (OR = 1.54, 1.42-1.67), a diagnosis of anaemia during pregnancy (OR = 12.03, 9.66-14.98) and indicators of lower socioeconomic status. Women were less likely to take these supplements if they reported having had a malaria episode before (OR = 0.57, 0.53-0.62) or during pregnancy (OR = 0.45, 0.41-0.51), reported having contracted other infectious diseases (OR = 0.45, 0.42-0.49), were multiparous (OR = 0.73, 0.66-0.80), had preeclampsia/eclampsia (OR = 0.48, 0.38-0.61), or other diseases (OR = 0.55, 0.44-0.69) during pregnancy. Similar patterns of association emerged when iron supplementation alone and supplementation with both iron and FA were evaluated.

Conclusions

FA and iron supplementation are low among pregnant women in Northern Tanzania, in particular among women with co-morbidities before or during pregnancy. Attempts should be made to increase supplementation both in general and among women with pregnancy complications.

Prepregnancy body mass index and gestational weight gain with the outcome of pregnancy: a 13-year study of 292,568 cases in China

PURPOSE

We aimed to investigate the combined associations of prepregnancy body mass index (BMI) and gestational weight gain (GWG) with pregnancy outcomes in Chinese women.

METHODS

Data for 292,568 singleton term pregnancies were selected from 1993 to 2005 based on the Perinatal Health Care Surveillance System, with anthropometric measurements being collected prospectively. Prepregnancy BMI was categorized according to the definitions of the World Health Organization (WHO). Total GWG was categorized into four groups. Adjusted associations of prepregnancy BMI and GWG with outcomes of interest were estimated using logistic regression analyses. GWG was categorized as below, within and above the Institute of Medicine (IOM) (2009) recommendations.

RESULTS

Maternal overweight and high GWG or GWG above the IOM recommendation were associated with hypertensive disorders complicating pregnancy, cesarean delivery, macrosomia and large-for-gestational-age (LGA) infants. Maternal underweight and low GWG or GWG below the IOM recommendation were risk factors for low-birth-weight (LBW) and small-for-gestational-age (SGA) infants. Moreover, being overweight [odds ratio (OR) 1.2, 95 % confidence interval (CI) 1.0-1.3) and having a low weight gain (OR 1.1, 95 % CI 1.0-1.1) increased the risk of newborn asphyxia.

CONCLUSION

Being overweight/obese and having a high weight gain, as well as being underweight and having a low weight gain, were associated with increased risks for adverse pregnancy outcomes in Chinese women.

Prenatal nutrition, epigenetics and schizophrenia risk: can we test causal effects?

We posit that maternal prenatal nutrition can influence offspring schizophrenia risk via epigenetic effects. In this article, we consider evidence that prenatal nutrition is linked to epigenetic outcomes in offspring and schizophrenia in offspring, and that schizophrenia is associated with epigenetic changes. We focus upon one-carbon metabolism as a mediator of the pathway between perturbed prenatal nutrition and the subsequent risk of schizophrenia. Although post-mortem human studies demonstrate DNA methylation changes in brains of people with schizophrenia, such studies cannot establish causality. We suggest a testable hypothesis that utilizes a novel two-step Mendelian randomization approach, to test the component parts of the proposed causal pathway leading from prenatal nutritional exposure to schizophrenia. Applied here to a specific example, such an approach is applicable for wider use to strengthen causal inference of the mediating role of epigenetic factors linking exposures to health outcomes in population-based studies.

Does obesity modify the association of supplemental folic acid with folate status among nonpregnant women of childbearing age in the United States?

BACKGROUND

Obesity is associated with an increased risk of having a pregnancy affected by a neural tube defect (NTD). It is not clear whether the amount of folic acid required by obese women to protect against NTDs is the same as that for nonobese women.

METHODS

We analyzed data from the National Health and Nutrition Examination Survey, representative of the noninstitutionalized civilian U.S. population, to assess whether body mass index (BMI; normal weight, overweight, and obese categories) modified the association between supplemental folic acid intake and folate status. We estimated the geometric mean concentration among nonpregnant women of childbearing age (15-44 years) during the postfortification period of: serum folate (2003-2008); red blood cell (RBC) folate (2007-2008); and plasma total homocysteine (tHcy; 2003-2006), adjusted for age, race and ethnicity, and total dietary folate expressed as dietary folate equivalents for strata of supplement use and BMI.

RESULTS

BMI was inversely associated with serum folate among women who did not use supplements containing folic acid; no differences between women in different BMI categories were observed among supplement users. Regardless of supplement use, obese women had the highest RBC folate concentrations. There were no differences in tHcy by BMI, regardless of supplement use.

CONCLUSIONS

These results do not support a straightforward modification of the relationship between supplemental folic acid intake and folate status by BMI. In this population, BMI may affect the body distribution of folate, as reflected by lower serum and higher RBC folate levels in obese women who do not use supplements.

Maternal tea consumption during early pregnancy and the risk of spina bifida

Studies have demonstrated that catechin, an antioxidant found in tea, can reduce the bioavailability of folate. Because periconceptional folic acid intake has been demonstrated to reduce the risk of spina bifida, tea consumption may put pregnant women at risk because of its possible antifolate properties. Using data collected in the Slone Epidemiology Center Birth Defects Study, we examined whether tea consumption during early pregnancy was associated with an increased risk of spina bifida. Mothers of 518 spina bifida cases and 6424 controls were interviewed within 6 months after delivery about pregnancy events and exposures. Data on tea intake were collected during three periods (1976-1988, 1998-2005 and 2009-2010). Logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for study center. Intake of both periconceptional food folate and diet and supplemental folic acid were examined as a potential effect modifier. For 1976 to 1988, ORs were not elevated for daily tea intake. For 1998 and onward, ORs were also close to 1.0, but there was a modest increase for those who drank more than 3 cups/day (OR, 1.92; 95% CI, 0.84-4.38). Among women with total folic acid intake greater than 400 μg, consumption of 3 cups or more of tea per day was associated with an increased risk of spina bifida in 1976 to 1988 (OR, 2.04; 95% CI, 0.69-7.66) and in the later periods (OR, 3.13; 95% CI, 0.87-11.33). Our data do not support an overall association between tea consumption and spina bifida, but there is a suggestion of a possible interaction between higher levels of folic acid intake and tea consumption.