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

Not all cases of neural-tube defect can be prevented by increasing the intake of folic acid

Some countries have introduced mandatory folic acid fortification, whereas others support periconceptional supplementation of women in childbearing age. Several European countries are considering whether to adopt a fortification policy. Projections of the possible beneficial effects of increased folic acid intake assume that the measure will result in a considerable reduction in neural-tube defects (NTD) in the target population. Therefore, the objective of the present study is to evaluate the beneficial effects of different levels of folic acid administration on the prevalence of NTD. Countries with mandatory fortification achieved a significant increase in folate intake and a significant decline in the prevalence of NTD. This was also true for supplementation trials. However, the prevalence of NTD at birth declined to approximately five cases at birth per 10 000 births and seven to eight cases at birth or abortion per 10 000 births. This decline was independent of the amount of folic acid administered and apparently reveals a ‘floor effect’ for folic acid-preventable NTD. This clearly shows that not all cases of NTD are preventable by increasing the folate intake. The relative decline depends on the initial NTD rate. Countries with NTD prevalence close to the observed floor may have much smaller reductions in NTD rates with folic acid fortification. Additionally, potential adverse effects of fortification on other vulnerable population groups have to be seriously considered. Policy decisions concerning national mandatory fortification programmes must take into account realistically projected benefits as well as the evidence of risks to all vulnerable groups.

Optically active supramolecular complexes of water-soluble achiral polythiophenes and folic acid: spectroscopic studies and sensing applications

Optically active supramolecular complexes of water-soluble achiral polythiophene (PT) derivatives, PMTPA or PMTEA (Chart 1), and folic acid have been prepared; and the complex formation processes have been studied by absorption, emission, and circular dichroism (CD) spectroscopies. The complexes exhibited unique split-type induced CDs in the pi-pi* transition region of PTs, indicating that the molecular chirality of the glutamic acid moiety in folic acid was expressed in PT backbones. The influences of temperature, solvent composition, and the structures of the inducing molecules on the chirality induction to PTs were also investigated, and a possible mechanism for the formation of chiral superstructures was proposed. Furthermore, it was found that, upon addition of folic acid into aqueous solution of PTs (PMTPA or PMTEA), a dramatic color change from yellow to purple along with the emission quenching of PT derivatives was observed. PMTEA, having one fewer carbon in the hydrophobic side chain relative to PMTPA, showed better selectivity toward folic acid sensing over ATP because of its higher solubility in water and the appropriate hydrophilic/hydrophobic balance in the complex. Therefore, it can be applied as a colorimetric and fluorescent probe for detecting folic acid with high selectivity and sensitivity. Besides naked-eye detection of folic acid, the detection limit can be extended to be 10 (-8) M by using fluorometry and PMTEA as the probing molecule.

Review of the magnitude of folate and vitamin B12 deficiencies worldwide

Human deficiencies of folate and vitamin B12 result in adverse effects which may be of public health significance, but the magnitude of these deficiencies is unknown. Therefore, we examine the prevalence data currently available, assess global coverage of surveys, determine the frequency with which vitamin status assessment methods are used, and identify patterns of status related to geographical distribution and human development. Surveys were identified through PubMed and the Vitamin and Mineral Nutrition Information System at the World Health Organization (WHO). Since different thresholds were frequently used to define deficiency, measures of central tendency were used to compare blood vitamin concentrations among countries. The percentage of countries with at least one survey is highest in the WHO Regions of South-East Asia and Europe. Folate and vitamin B12 status were most frequently assessed in women of reproductive age (34 countries), and in all adults (27 countries), respectively. Folate status assessment surveys assessed plasma or serum concentrations (55%), erythrocyte folate concentrations (21%), or both (23%). Homocysteine was assessed in one-third of the surveys of folate and vitamin B12 status (31% and 34% respectively), while methylmalonic acid was assessed in fewer surveys of vitamin B12 status (13%). No relationship between vitamin concentrations and geographical distribution, level of development, or population groups could be identified, but nationally representative data were few. More representative data and more consistent use of thresholds to define deficiency are needed in order to assess whether folate and vitamin B12 deficiencies are a public health problem.

National Neural Tube Defects Prevention Program in China

Neural tube defects (NTD) are among the most common and devastating birth defects. Annually, in China, between 80,000 and 100,000 pregnancies result in children born with NTD. Northern China has the highest known rate of NTD in the world. Birth defects are becoming the leading cause of infant mortality in the urban and developed areas in China. The results of studies conducted in the early 1990s and early 2000s showed significant geographic and seasonal variations of folate status among Chinese women of childbearing age, with lower serum and red blood cell folate levels in northern China. In the north, 32% to 35% of women had low plasma folate and low red blood cell folate, and folate levels were significantly lower in spring than in fall. Since 1993, Peking University Health Science Center (formerly Beijing Medical University), collaborating with the US Centers for Disease Control and Prevention (CDC), has conducted a large-scale study to evaluate a public health campaign in China among women preparing for marriage in order to determine the effectiveness of daily supplementation of 400 microg of folic acid alone in preventing NTD in both the north and the south of China. The results showed that among the fetuses or infants of the women who took periconceptional folic acid, the reduction in risk of NTD was 85% in the northern region and 40% in the southern region. Daily intake of 400 microg of folic acid may also reduce the risk of nonsyndromic orofacial clefts. We found no evidence that daily consumption of folic acid before and during early pregnancy influenced the risk of miscarriage or twinning. In 2001, the Chinese Ministry of Health and the Chinese Disabled Person Federation released a National Action Plan for Reducing Birth Defects and Disabilities in China for 2002-2010. The Action Plan aims to improve birth outcomes, to reduce infant mortality by reducing the risk of birth defects and disabilities, and to ensure that every baby is born healthy.

Gene-nutrient interactions: importance of folic acid and vitamin B12 during early embryogenesis

The role that nutritional factors play in mammalian development has received renewed attention over the past two decades as the scientific literature has exploded with reports that folic acid supplementation in the periconceptional period can protect embryos from a number of highly significant malformations. As is often the case, the relationship between B vitamin supplementation and improved pregnancy outcomes is more complicated than initially perceived, as the interaction between nutritional factors and selected genes must be considered. In this review, we attempt to summarize the complex clinical and experimental literature on nutritional factors, their biological transport mechanisms, and interactions with genetic polymorphisms that impact early embryogenesis. While not exhaustive, our goal was to provide an overview of important gene-nutrient interactions, focusing on folic acid and vitamin B12, to serve as a framework for understanding the multiple roles they play in early embryogenesis.

Impact of micronutrient supplementation during pregnancy on birth weight, duration of gestation, and perinatal mortality in rural western China: double blind cluster randomised controlled trial

OBJECTIVE

To examine the impact of antenatal supplementation with multiple micronutrients or iron and folic acid compared with folic acid alone on birth weight, duration of gestation, and maternal haemoglobin concentration in the third trimester.

DESIGN

Cluster randomised double blind controlled trial.

SETTING

Two rural counties in north west China.

PARTICIPANTS

5828 pregnant women and 4697 live births.

INTERVENTIONS

Villages were randomised for all pregnant women to take either daily folic acid (control), iron with folic acid, or multiple micronutrients with a recommended allowance of 15 vitamins and minerals.

MAIN OUTCOME MEASURES

Birth weight, length, and head circumference measured within 72 hours after delivery. Neonatal survival assessed at the six week follow-up visit.

RESULTS

Birth weight was 42 g (95% confidence interval 7 to 78 g) higher in the multiple micronutrients group compared with the folic acid group. Duration of gestation was 0.23 weeks (0.10 to 0.36 weeks) longer in the iron-folic acid group and 0.19 weeks (0.06 to 0.32 weeks) longer in the multiple micronutrients group. Iron-folic acid was associated with a significantly reduced risk of early preterm delivery (<34 weeks) (relative risk 0.50, 0.27 to 0.94, P=0.031). There was a significant increase in haemoglobin concentration in both iron-folic acid (5.0 g/l, 2.0 to 8.0 g/l, P=0.001) and multiple micronutrients (6.9 g/l, 4.1 to 9.6 g/l, P<0.001) groups compared with folic acid alone. In post hoc analyses there were no significant differences for perinatal mortality, but iron-folic acid was associated with a significantly reduced early neonatal mortality by 54% (relative risk 0.46, 0.21 to 0.98).

CONCLUSION

In rural populations in China antenatal supplementation with iron-folic acid was associated with longer gestation and a reduction in early neonatal mortality compared with folic acid. Multiple micronutrients were associated with modestly increased birth weight compared with folic acid, but, despite this weight gain, there was no significant reduction in early neonatal mortality. Pregnant women in developing countries need sufficient doses of iron in nutrient supplements to maximise reductions in neonatal mortality. Trial registration ISRCTN08850194.

Improper supplementation habits of folic acid intake by Hungarian pregnant women: improper recommendations

BACKGROUND

Neural tube defects (NTDs) are some of the most common congenital anomalies. Proper folic acid supplementation is a dominant risk factor, which has been shown to decrease the incidence of NTDs. In Canada, the incidence of neuroblastoma has presented a considerable decrease of 60% as a result of enrichment cereal grain flours with synthetic folic acid. The aim of this study was to investigate the effect of folic acid intake by pregnant women on the incidence of NTDs and neuroblastoma.

METHODS

Regular folic acid intake has been recommended to pregnant women in Hungary since the eighties of the last century by health visitors eventually raking effect as an official protocol which had been released in 1997. During 2001, 2002 and 2003, folic acid intake habits of pregnant women were evaluated by health visitors, proving to be successful in collecting data from 95.06% of the pregnant women. The incidence of NTDs has been registered by the Hungarian National Centre of Epidemiology, Department of Human Genetics and Teratology. The Pediatric Cancer Registry provided the incidence of neuroblastoma in children.

RESULTS

Consistent findings revealed a regular intake of supplementary folic acid products by 68.71% of the pregnant women. Out of these, 93.13% of pregnant women who were taking folic acid, started the supplementation after their 7 weeks of pregnancies, a time designated as the completion period of the development of the neural tube. The dose of folic acid supplementation was evaluated as less than 5 mg/day in 84.75% of the pregnant women. In Hungary, the incidence of NTDs has remained constant, while the incidence of neuroblastoma has shown constant slight increase in spite of the introduction of folic acid supplementation in 1997.

CONCLUSIONS

Based on our experience, folic acid supplementation was initiated after the recognition of pregnancy and its application in a dose of lower than 5 mg/day neither decreased the incidence of NTDs nor did it have an effect on the neuroblastoma incidence. It is implicated that proper folic acid supplementation, which is started from the conception, can be achieved only with the enrichment of cereal grain flours.

Prevention of NTDs with periconceptional multivitamin supplementation containing folic acid in China

BACKGROUND

Maternal nutritional factors seem to contribute substantially to the complex etiologies of NTDs. Foremost among these factors is the periconceptional use of supplementation containing folic acid, which is associated with a reduction in the risk of women having NTD-affected pregnancies. This study was designed to observe the effectiveness of multivitamin supplementation containing folic acid in preventing NTDs in a Chinese population and to detect factors that would impact the effectiveness.

METHODS

Through family planning networks, a population-based community intervention study was carried out in 18 counties of China. Participants were divided into an intervention (taking multivitamin) group and a control group, and were followed up according to periconceptional multivitamin supplementation (in general 6 mg) for 2 years. Women who had a pregnancy were followed up from 28 weeks gestation at least to pregnancy termination, and the outcome was recorded. The incidence rate of the two groups and the relative risks were calculated to evaluate the efficacy of the multivitamin supplement in preventing NTDs.

RESULTS

During 2000 and 2002, all of the women having pregnancies with birth defects and women whose pregnancies were without any birth defects were interviewed. Nine NTDs were recorded from 25,444 pregnancies (NTD birth prevalence = 0.35/1,000 pregnancies) in the intervention group and 48 NTDs among 26,599 pregnancies (NTD birth prevalence = 1.80/1,000 pregnancies) in the control group. The protective rate was 80.4%.

CONCLUSIONS

Periconceptional multivitamin supplementation containing folic acid can prevent the occurrence of NTDs with the beneficial effect dependent on the frequency and timing of the supplementation. Our study suggests that multivitamin supplement containing folic acid taken from a time point of 2 months before conception and continuing until completion of the second month after conception and taken more than five times per week can significantly reduce the risks of NTDs.

Influence of green and black tea on folic acid pharmacokinetics in healthy volunteers: potential risk of diminished folic acid bioavailability

Previous in vitro studies using Caco-2 cell monolayers suggested a possible interaction between green and black tea and folic acid at the level of intestinal absorption. The main purpose of the present study was to investigate a possible pharmacokinetic interaction between tea and folic acid in healthy volunteers. In an open-labeled randomized cross-over study, the pharmacokinetic interaction between tea and folic acid (0.4 mg and 5 mg) was investigated in healthy volunteers. Water was used as the reference drink. Subjects ingested 0.4 mg folic acid tablets with water, green or black tea (0.3 g extract/250 ml) or 5 mg folic acid tablets with water or green tea (0.3 g extract/250 ml). Blood samples were collected over a period of 8 h. Serum folate analysis was carried out by a competitive immunoassay which uses direct chemiluminescent technology. At the 0.4 mg folic acid dose, green and black tea reduced the mean C(max) of serum folate by 39.2% and 38.6%, and the mean AUC(0 --> infinity) by 26.6% and 17.9%, respectively. At the 5 mg folic acid dose, the mean C(max) of serum folate was reduced by 27.4% and the mean AUC(0 --> infinity) was decreased significantly by 39.9% by the co-application of green tea. The present results suggest an in vivo interaction between tea and folic acid with even low concentrations of green and black tea extracts yielding decreased bioavailabilities of folic acid.

Autoantibodies to folate receptor during pregnancy and neural tube defect risk

Periconceptional folic acid can reduce the occurrence of neural tube defects (NTDs) by up to 70%, and autoantibodies for folate receptors (FRs) have been observed in serum from women with a pregnancy complicated by an NTD. This population-based cohort study has examined serum from pregnant mothers for autoantibodies to FRs, antibodies to bovine folate binding protein (FBP), and inhibition of folic acid binding to FR and FBP in association with NTD risk. The mid-gestational maternal serum specimens used for this study were collected during the 15-18th week of pregnancy. Samples were obtained from the California Birth Defects Monitoring Program; 29 mothers had a pregnancy complicated by spina bifida and 76 mothers had unaffected children. The presence of IgG and IgM antibodies to human FR, bovine FBP, and inhibition of folic acid binding to FR and FBP was determined. Higher activity of IgM to FBP in cases verses controls was observed (P=0.04). Higher activity of IgM and IgG autoantibodies to FR was observed (P<0.001 and P=0.04, respectively). Risk estimates at two standard deviations above average control antibody concentrations were OR=2.07 (CI=1.02, 4.06) for anti-FBP IgM, OR=2.15 (CI=1.02, 4.69) for anti-FR IgG and OR=3.19 (CI=1.47, 6.92) for anti-FR IgM. These data support the hypothesis that high titers of antibodies and blocking of folic acid binding to FRs by maternal serum should be regarded as risk factors for NTDs.

[Pregnancy and epilepsy. Retrospective analysis of 118 patients]

BACKGROUND

The aim of this study was to evaluate the treatment of women with epilepsy investigated prior to or during pregnancy.

PATIENTS

One hundred eighteen women (median age 28.9 years) with idiopathic (n=43), cryptogenic (n=41), or symptomatic (n=29) epilepsy and appearing for special pregnancy planning advice at a German epileptology clinic were evaluated. All patients were investigated between 2002 and 2007.

FINDINGS

Of the study patients, 69 were seen prior to pregnancy, 41 (59.4%) were on monotherapy with antiepileptic drugs (AED), and 22 (31.9%) were already on folic acid supplementation. A change in AED medication was recommended in 50 (72.5%). Ninety-three of the patients were seen during pregnancy, most often during the first trimenon (n=44). Fifty-one (55%) were on AED monotherapy, most often with lamotrigine (n=24) or valproate (n=13). During pregnancy, seizure frequency increased in 33 women (35.5%) and decreased in 14 (15%).

CONCLUSION

Monotherapy with AED should be established if possible, and folic acid supplementation should be started prior to pregnancy.

Quantification of folic acid in human feces after administration of Bifidobacterium probiotic strains

BACKGROUND

Folic acid, or vitamin B9, is involved in appropriate regulation of DNA replication, synthesis of purines and deoxythymidine (dTMP), conversion of homocysteine to methionine, histidine catabolism, and correct differentiation of the neural tube during fetal organogenesis. Folic acid from food sources is almost completely absorbed in the small intestine, mostly in the jejunum, and does not reach the large intestine. The administration of probiotic strains able to synthesize folates de novo and release them in the extracellular space may provide an additional, constant endogenous source of this important vitamin in the intestinal lumen of humans.

METHODS

A pilot study involving 23 healthy volunteers was conducted to evaluate the ability of 3 probiotic strains, Bifidobacterium adolescentis DSM 18350, B. adolescentis DSM 18352, and Bifidobacterium pseudocatenulatum DSM 18353, to produce folates in the human intestine. Volunteers were randomly assigned to 1 of 3 groups for treatment with a specific probiotic strain (5 x 10(9) colony forming units/d). Strain effectiveness was evaluated by determination of the folate concentration in feces evacuated within 48 hours before and after administration of the probiotics. Quantification of microorganisms belonging to the genus Bifidobacterium was performed in parallel to folate analysis.

RESULTS

Ingestion of these probiotic strains resulted in a significant increase of folic acid concentration in human feces in all treated groups. Analysis of the fecal Bifidobacteria confirmed the potential of all strains, especially B. adolescentis DSM 18352, to colonize the intestinal environment.

CONCLUSIONS

The demonstrated ability of the probiotic microorganisms B. adolescentis DSM 18350, B. adolescentis DSM 18352, and B. pseudocatenulatum DSM 18353 to synthesize and secrete folates in the human intestinal environment may provide a complementary endogenous source of such molecules, which is especially useful for the homeostasis of mucosal enterocytes of the colon and, unlike oral administration of the vitamin, ensures its constant bioavailability.

Labor market productivity costs for caregivers of children with spina bifida: a population-based analysis

BACKGROUND

Caregiver productivity costs are an important component of the overall cost of care for individuals with birth defects and developmental disabilities, yet few studies provide estimates for use in economic evaluations.

OBJECTIVE

This study estimates labor market productivity costs for caregivers of children and adolescents with spina bifida.

METHODS

Case families were recruited from a state birth defects registry in Arkansas. Primary caregivers of children with spina bifida (N = 98) reported their employment status in the past year and demographic characteristics. Controls were abstracted from the Current Population Survey covering the state of Arkansas for the same time period (N = 416). Estimates from regression analyses of labor market outcomes were used to calculate differences in hours worked per week and lifetime costs.

RESULTS

Caregivers of children with spina bifida worked an annual average of 7.5 to 11.3 hours less per week depending on the disability severity. Differences in work hours by caregivers of children with spina bifida translated into lifetime costs of $133,755 in 2002 dollars using a 3% discount rate and an age- and sex-adjusted earnings profile. Including caregivers' labor market productivity costs in prevention effectiveness estimates raises the net cost savings per averted case of spina bifida by 48% over the medical care costs alone.

CONCLUSIONS

Information on labor market productivity costs for caregivers can be used to better inform economic evaluations of prevention and treatment strategies for spina bifida. Cost-effectiveness calculations that omit caregiver productivity costs substantially overstate the net costs of the intervention and underestimate societal value.

Theory of planned behavior and multivitamin supplement use in Caucasian college females

The objective of this study was to identify predictors of the use of multivitamin supplements (MVS) among Caucasian college females utilizing the Theory of Planned Behavior (TPB). Variables of the TPB and the self-reported use of multivitamin supplements were measured by two separate surveys within 1 week with a convenience sample of 96 Caucasian college student females. Two attitudinal beliefs and one control belief significantly predicted behavioral intention to use multivitamin. A belief that taking multivitamin supplements helps to feel and look good was the most important predictor of the use of multivitamin supplements. EDITORS' STRATEGIC IMPLICATIONS: Findings from this study, although in need of replication, suggest that prevention campaigns would be more successful if messages used to reach these females were consistent with perceived beliefs regarding benefits of using MVS. More broadly, TPB appears to offer a useful framework for understanding or predicting behavior based on psychological constructs theorized to influence behavior.

Effect of different dosage and administration schedules of folic acid on blood folate levels in a population of Honduran women of reproductive age

Background

Observational studies and clinical trials have shown conclusive evidence that periconceptional folic acid supplementation prevents up to 70 % of neural tube defects (NTD). The Honduran government wanted to implement a supplementation programme of folic acid but needed to assess the relative effects of two dosages of folic acid.

Objective

To determine the effect of two dosages of folic acid on blood folate levels in Honduran female factory workers aged 18 to 49 years.

Design

This was a randomized, double-blind control supplementation trial conducted in Choloma, Honduras. A total of 140 eligible women were randomly assigned to two dosage groups and followed up for 12 weeks. One group received a daily dosage of 1 mg folic acid and the other a once weekly dosage of 5 mg. Serum folate and red blood cell folate levels were determined by radioassay at baseline, 6 weeks and 12 weeks.

Results

Serum folate levels increased from 6·3 (se 0·2) to 14·9 (se 0·6) ng/ml (P < 0·0001) in women assigned to the 1 mg/d group and from 6·9 (se 0·3) to 10·1 (se 0·4) ng/ml (P < 0·0001) in those assigned to the 5 mg/week group. Red blood cell folate concentrations also increased significantly in both groups, albeit more slowly. Educational level, age and BMI were not associated with the changes in serum and red blood cell folate levels during the supplementation period. However, a differential effect on serum folate levels by dosage group and time was observed.

Conclusions

Although both folate supplementation regimens increased serum and red blood cell folate levels significantly among the women studied, blood folate levels that are considered to be protective of NTD were reached faster with the daily dosage of 1 mg folic acid.

Weekly may be as efficacious as daily folic acid supplementation in improving folate status and lowering serum homocysteine concentrations in Guatemalan women

Daily folic acid (FA) supplementation improves folate status, lowers circulating homocysteine (Hcy) concentrations, and reduces the risk of neural tube defects. Little is known about the efficacy of weekly FA supplementation. The objective of this study was to compare the efficacy of weekly and daily FA supplementations in improving folate and vitamin B-12 status and lowering Hcy concentrations in healthy reproductive-aged women. A randomized, double-blind supplementation trial was conducted in Guatemala. A total of 459 women were assigned randomly to 4 groups to receive weekly (5000 or 2800 microg) or daily (400 or 200 microg) FA for 12 wk. Daily and weekly iron, zinc, and vitamin B-12 were also provided. We determined serum and RBC folate by microbiological assays, but the latter was available only at baseline. Serum Hcy and vitamin B-12 were also measured. We used generalized linear regression models to assess the effects of treatment on biochemical indicators. Supplementation improved folate status similarly across all 4 groups. Overall, mean serum folate concentrations increased by 15.4 nmol/L (95% CI: 13.8, 16.9) and the geometric mean serum Hcy concentration decreased by 9.8% (95% CI: -12.3, -7.1). Daily supplementation improved serum vitamin B-12 by 20% (95% CI: 8, 33.2), whereas weekly supplementation had no effect. In conclusion, weekly FA (either high or low dose) plus vitamin B-12 may be as efficacious as daily supplementation in improving serum folate and lowering Hcy concentrations in healthy women of reproductive age.

Folate status and homocysteine response to folic acid doses and withdrawal among young Chinese women in a large-scale randomized double-blind trial

BACKGROUND

There are no large randomized trials of the effect of folic acid dosing regimens on blood folate and homocysteine concentrations.

OBJECTIVE

We aimed to evaluate the changes in folate and homocysteine concentrations in response to different folic acid doses and to withdrawal in young women not exposed to other sources of folic acid.

DESIGN

Women (n = 1108) were randomly assigned to 1 of 6 intervention groups for which daily intakes of folic acid for 6 mo were 100 microg 1 time/d, 25 microg 4 times/d, 400 microg 1 time/d, 100 microg 4 times/d, 4000 microg 1 time/d, or 4000 microg 1 time/wk. Plasma and red blood cell folate and homocysteine concentrations were measured at baseline; at 1, 3, and 6 mo; and 3 mo after the discontinuation of folic acid.

RESULTS

Folate and homocysteine concentrations were not different at baseline between the groups who had the same daily intake of folic acid as a single dose or multiple doses (P = 0.058). Plasma folate concentrations plateaued at 3 mo with 108% (95% CI: 97.7%, 120%), 259% (95% CI: 240%, 279%), 460% (95% CI: 417%, 503%), and 142% (95% CI: 123%, 162%) observed increases for the folic acid groups receiving 100, 400, and 4000 microg/d and 4000 microg/wk, respectively. The rate of reduction in folate concentrations during the 3 mo after cessation of folic acid was dose-dependent-higher intakes were associated with faster reductions.

CONCLUSIONS

Changes in folate and homocysteine concentrations were unaffected by different dosing schedules. After folic acid cessation, blood folate declined rapidly, which indicated that the intervention-enhanced folate status was rapidly diminished.

Preconceptional folic acid supplement use in Lebanon

OBJECTIVE

The objective of the present study was to assess the prevalence and determinants of preconceptional folic acid supplement use among pregnant women in Lebanon.

DESIGN/SETTING/SUBJECTS

The study was a descriptive epidemiological study. Analysis was performed on 5280 deliveries admitted to twelve member hospitals of the National Collaborative Perinatal Neonatal Network during the period September 2003-January 2005. Information on folic acid intake and maternal and neonatal characteristics were obtained from obstetric charts along with direct interviews performed by trained personnel. Logistic regression was performed to determine the predictors of preconceptional folic acid use.

RESULTS

The overall use of preconceptional folic acid supplementation was 14.0 % (18.6 % in urban hospitals v. 2.7 % in rural hospitals). Higher socio-economic status, lower parity and having a history of previous spontaneous abortions were significantly associated with preconceptional folic acid use.

CONCLUSION

Our study shows that Lebanon currently has a low rate of preconceptional folic acid supplement use. Intervention through the means of awareness campaigns needs to be implemented on a national level.

Decline in the prevalence of neural tube defects following folic acid fortification and its cost-benefit in South Africa

BACKGROUND

In October 2003 South Africa embarked on a program of folic acid fortification of staple foods. We measured the change in prevalence of NTDs before and after fortification and assessed the cost benefit of this primary health care intervention.

METHODS

Since the beginning of 2002 an ecological study was conducted among 12 public hospitals in four provinces of South Africa. NTDs as well as other birth defect rates were reported before and after fortification. Mortality data were also collected from two independent sources.

RESULTS

This study shows a significant decline in the prevalence of NTDs following folic acid fortification in South Africa. A decline of 30.5% was observed, from 1.41 to 0.98 per 1,000 births (RR = 0.69; 95% CI: 0.49-0.98; p = .0379). The cost benefit ratio in averting NTDs was 46 to 1. Spina bifida showed a significant decline of 41.6% compared to 10.9% for anencephaly. Additionally, oro-facial clefts showed no significant decline (5.7%). An independent perinatal mortality surveillance system also shows a significant decline (65.9%) in NTD perinatal deaths, and in NTD infant mortality (38.8%).

CONCLUSIONS

The decrease in NTD rates postfortification is consistent with decreases observed in other countries that have fortified their food supplies. This is the first time this has been observed in a predominantly African population. The economic benefit flowing from the prevention of NTDs greatly exceeds the costs of implementing folic acid fortification.

Trends in the postfortification prevalence of spina bifida and anencephaly in the United States

BACKGROUND

The prevalence of NTDs in the US declined significantly after mandatory folic acid fortification; however, it is not known if the prevalence of NTDs has continued to decrease in recent years relative to the period immediately following the fortification mandate.

METHODS

Population-based data from 21 birth defects surveillance systems were used to examine trends in the birth prevalence of spina bifida and anencephaly during 1999-2000, 2001-2002, and 2003-2004. Prevalence data were stratified by non-Hispanic White, non-Hispanic Black, and Hispanic race or ethnicity. Prevalence ratios were calculated by dividing the birth prevalences during the later time periods (2001-2002 and 2003-2004) by the birth prevalences during 1999-2000.

RESULTS

During 1999-2004, 3,311 cases of spina bifida and 2,116 cases of anencephaly were reported. Hispanic infants had the highest prevalences of NTDs for all years. For all infants, the combined birth prevalences of spina bifida and anencephaly decreased 10% from the 1999-2000 period to the 2003-2004 period. The decline in spina bifida (3%) was not significant; however the decline in anencephaly (20%) was statistically significant.

CONCLUSIONS

While the prevalences of spina bifida and anencephaly in the United States have declined since folic acid fortification in the food supply began, these data suggest that reductions in the prevalence of anencephaly continued during 2001-2004 and that racial and ethnic and other disparities remain.

Folic Acid for the Prevention of Neural Tube Defects: The Danish Experience

Evidence from controlled trials suggests that ingestion of 0.4 mg of folic acid per day in the periconceptional period is effective in preventing neural tube defects (NTD). For this reason, most countries recommend that women planning pregnancy take folic acid supplements in the periconceptional period, and some countries even fortify stable foods with folic acid. Denmark exemplifies a country with a relatively conservative attitude with respect to taking action in these matters. In 1999, a national information campaign was launched that recommended women planning pregnancy take 0.4 mg of folic acid periconceptionally, but with the moderation that women who eat a healthy diet do not need to take folic acid supplement. The campaign was repeated during 2001. The results of the latter campaign were evaluated by using data from a national survey among pregnant women conducted simultaneously with the campaign by the Danish National Birth Cohort. An increase in the proportion of folic acid users took place concomitantly with the launching of the information events, but the increase was limited. Among women who did not plan their pregnancy, a small proportion had taken folic acid supplements periconceptionally, and this proportion did not change concomitantly with the campaign. Young age and low education were factors associated with low likelihood of taking folic acid. It seems that different and more efficient actions are needed if a more substantial proportion of Danish women and their fetuses are going to benefit from the knowledge that folic acid supplementation in the periconceptional period can prevent NTD.

Production of folates by yeasts in Tanzanian fermented togwa

We have investigated the impact of different yeasts and fermentation time on folate content and composition in a fermented maize-based porridge, called togwa, consumed in rural areas in Tanzania. The yeasts studied, originally isolated from indigenous togwa, belong to Issatchenkia orientalis, Pichia anomala, Saccharomyces cerevisiae, Klyveromyces marxianus and Candida glabrata. The main folate forms found, detected and quantified by HPLC during the fermentations were 5-methyl-tetrahydrofolate (5-CH(3)-H(4)folate) and tetrahydrofolate (H(4)folate). The content of H(4)folate, per unit togwa, remained fairly stable at a low level throughout the experiment for all strains, whereas the 5-CH(3)-H(4)folate concentration was highly dependent on yeast strain as well as on fermentation time. The highest folate concentration was found after 46 h of fermentation with C. glabrata (TY26) (6.91+/-0.14 microg 100 mL(-1)), corresponding to a 23-fold increase compared with unfermented togwa. The cell concentration per se could not predict the togwa folate level, as shown by the much higher specific folate content (g folate CFU(-1)) in the S. cerevisiae strain (TY08) compared with the other species tested. This study provides useful data when trying to maximize folate content in togwa as well as in other yeast-fermented products.

Maternal obesity and risk of neural tube defects: a metaanalysis

We conducted a metaanalysis of published evidence on the relationship between maternal obesity and the risk of neural tube defects (NTDs). Eligible studies were identified from 3 sources: (1) PubMed search of articles that were published from January 1980 through January 2007, (2) reference lists of publications that were selected from the PubMed search, and (3) reference lists of review articles on obesity and maternal outcomes that were published from January 2000 through January 2007. Twelve studies met inclusion criteria. A Bayesian random effects model was used for the metaanalysis and metaregression. Unadjusted odds ratios for an NTD-affected pregnancy were 1.22 (95% CI, 0.99-1.49), 1.70 (95% CI, 1.34-2.15), and 3.11 (95% CI, 1.75-5.46) among overweight, obese, and severely obese women, respectively, compared with normal-weight women. None of the study characteristics included in the metaregression analysis affected the results significantly. Maternal obesity is associated with an increased risk of an NTD-affected pregnancy.

Nutritional and genetic determinants of vitamin B and homocysteine metabolisms in neural tube defects: a multicenter case-control study

Neural tube defects (NTDs) are severe congenital malformations due to failure of neural tube formation in early pregnancy. The proof that folic acid prevents NTDs raises the question of whether other parts of homocysteine (Hcy) metabolism may affect rates of NTDs. This French case-control study covered: 77 women aged 17-42 years sampled prior to elective abortion for a severe NTDs (cases) and 61 women aged 20-43 years with a normal pregnancy. Plasma and erythrocyte folate, plasma B6, B12 and Hcy were tested as five polymorphisms MTHFR 677 C --> T, MTHFR 1298 A --> C, MTR 2756 A --> G, MTTR 66 A --> G and TCN2 776 C --> G. Cases had significantly lower erythrocyte folate, plasma folate, B12 and B6 concentrations than the controls, and higher Hcy concentration. The odds ratio was 2.15 (95% CI: 1.00-4.59) for women with the MTRR 66 A --> G allele and it was decreased for mothers carrying the MTHFR 1298 A --> C allele. In multivariate analysis, only the erythrocyte folate concentration (P = 0.005) and plasma B6 concentration (P = 0.020) were predictors. Red cell folate is the main determinant of NTDs in France. Folic acid supplement or flour fortification would prevent most cases. Increased consumption of vitamins B12 and B6 could contribute to the prevention of NTDs. Genetic polymorphisms played only a small role. Until folic acid fortification becomes mandatory, all women of reproductive age should consume folic acid in a multivitamin that also contains B12 and B6.

Folic acid and methionine in the prevention of teratogen-induced congenital defects in mice

INTRODUCTION

Periconceptional supplementation with multivitamins containing folic acid reduces the risk of congenital malformations. We have previously investigated the effect on the murine development of a multiple retinoic acid competitive antagonist, Bristol-Myers-Squibb 189453, showing that treated fetuses were affected with heart defects, thymus aplasia or hypoplasia, and severe anomalies of the central nervous system. Hereby, we analyzed the effects of nutritive therapy involving folic acid and methionine on teratogen-induced congenital defects in mice.

MATERIALS AND METHODS

A total of 132 outbred CD1 litters were studied. Pregnant mice were divided into four experimental groups, and an oral supplementation of H(2)O or folic acid, or methionine, or folic acid+methionine was administered from 0.5 days postcoitum until the end of pregnancy. At 7.5 days postcoitum, mice from all these groups were administered Bristol-Myers-Squibb 189453 to induce the teratogenic effect. At the end of pregnancy, fetuses were dissected and tissues were analyzed by histology and flow cytometric assays.

RESULTS

Folic acid reduces congenital heart diseases from 81.3% to 64.8%, neural tube defects from 20.3% to 3.7%, and thymus abnormalities from 98.4% to 27.8%, restoring a normal number of differentiated thymus cells. Methionine is less effective in contrasting congenital heart diseases and neural tube defects, and induces thymus cell proliferation but not differentiation. Folic acid+methionine weakly reduce congenital heart diseases and neural tube defects, but consistently reduce the incidence of fetuses affected with thymus pathologies from 98.4% to 67.7%.

CONCLUSIONS

Our results suggest that folic acid and methionine periconceptional supplementations may influence the incidence of congenital defects and may probably induce negative selection of embryos presenting developmental anomalies.

Pregnancy, epilepsy, and anticonvulsants

The majority of epileptic disorders are not self-limiting over time, and therefore require a long-lasting and often even lifelong antiepileptic drug (AED) treatment, in Wi/omen with epilepsy, the influence of their disease on the possibility and course of pregnancies, as well as the potential impact of the AED treatment on mother and child, are crucial questions.

This review addresses the clinically relevant knovledge concerning the impact of the disease itself and the AED treatment on fertility, pregnancy, delivery, the postpartum period, and teratogenicity. Some of the new AEDs appear to have a favorable profile due to a lack of clinically relevant interactions and promising teratogenic profiles. However, the finding of decreases in lamotrigine serum concentrations during hormonal contraception and pregnancy is an instructive example, shovt/ing that ongoing studies are urgently needed to further investigate stillunanswered questions. Several prospective multinational surveys are currently being performed, and should add essential information in this context.

Importance of folate-homocysteine homeostasis during early embryonic development

Although the beneficial effects of maternal folate supplementation in the periconceptional period have been shown to prevent neural tube defects, congenital heart defects and orofacial clefts, the exact protective mechanism of folates remains unknown. Folates affect DNA synthesis, amino acid metabolism and methylation of genes, proteins and lipids via S-adenosylmethionine-mediated one-carbon transfer reactions. Our laboratory has created several mouse knock out models of folate transport using gene targeting to inactivate folate receptor 1 (Folr1), folate receptor 2 (Folr2) and reduced folate carrier 1 (Slc19a1) genes. Gene ablation of both Folr1 and Slc19a1 leads to lethality, but with maternal folate supplementation, nullizygous embryos for both genes present with neural tube defects (NTDs) and congenital heart defects (CHDs). Folr1 nullizygous mice also exhibit orofacial clefts when the dams are provided with low folate supplementation during pregnancy. Finally, women with NTD-affected pregnancies have been reported to have high autoantibody titers against the folate receptor, potentially inhibiting the transport of folate to the developing embryo. This may be an explanation for some of the folate-responsive NTDs and perhaps other congenital malformations. Herein, we propose how homocysteinylation of the folate receptor may contribute to generation of these autoantibodies against the folate receptor.

The effects of prenatal use of folic acid and other dietary supplements on early child development

OBJECTIVE

Our objective was to evaluate in an exploratory framework the effects of prenatal use of folic acid and other dietary supplements on child development at around 3 years of life.

METHODS

Data from the 1988 National Maternal Infant Health Survey and the 1991 follow-up supplement is used. Performance indicators are formed based on 16 developmental assessment items completed by the mother to measure overall as well as domain specific (language, personal-social, gross-motor and fine-motor) development. Pooled as well as separate analyses by child race are performed. Multinomial and binary outcome logistic regression is used and several maternal and household characteristics are included as covariates.

RESULTS

Folic acid use was associated with improved gross-motor development with a more pronounced effect among African-American children, but there was marginally significant poorer performance for the personal-social domain. Zinc and calcium use were associated with increased risks on the overall development scale and two other developmental domains. The negative effects of Zinc on overall development were only observed among white children. On the contrary, vitamin A was associated with decreased risks on the overall development scale only among white children.

CONCLUSIONS

Study results suggest that while prenatal folic acid supplementation may improve development at 3 years of age, further research is needed in this regard. The results also emphasize the importance of further research into the use of prenatal calcium and zinc supplementation in a US population.

Preconceptional folic acid utilization in Israel: five years after the guidelines

OBJECTIVE

In Israel, a national survey was conducted in order to assess the efficacy of the ongoing national folic acid (FA) campaign launched in 2000. The Ministry of Health had issued official guidelines in August 2000 recommending daily FA supplementation for all childbearing age women.

METHODS

In 2005, structured interviews of pregnant and postpartum women were conducted by the nursing staff of the Maternal Child Health Clinics administered by the Public Health Service. The results of the 2005 survey are compared with similar surveys done in 2002 and 2000 (baseline).

RESULTS

In the 2005 survey (n=1860), FA awareness, knowledge, timing knowledge and preconceptional utilization were 90.3%, 80.8%, 74.6% and 34.0%, respectively. Education was significantly associated with compliance: only 13.6% of women with <12 years of education utilized FA preconceptionally versus 48.1% of women with >or=16 years. In the 2002 survey (n=1661), FA awareness, knowledge, and preconceptional utilization were 85%, 77.7% and 30.5%, respectively. In the 2000 survey (n=1719), FA awareness was 54.6%, knowledge was 17.6% and preconceptional utilization was 5.2%.

CONCLUSIONS

The national preconceptional FA campaign in Israel has resulted in significant increases in awareness, knowledge and preconceptional utilization.

Correlation between birth defects and dietary nutrition status in a high incidence area of China

OBJECTIVE

To investigate the association between birth defects and dietary nutrient intake in a high risk area of China.

METHODS

A dietary survey was performed and serum folic acid was measured in women whose pregnancy was affected by neural tube defects (NTDs) or unaffected by any birth defects (BDs) in Zhongyang and Jiaokou Counties in Shanxi Province of China.

RESULTS

The local average consumption of foods including dark green vegetables, fruits, fat and meat, and nutrient intake (e.g., energy, protein, retinol, riboflavin, vitamin E, and selenium) were lower than the national average level. In women of childbearing age, these regions, the intake of nutrients was much lower than the recommended nutrient intake (9%-77%). The case-control dietary nutrition study of women whose pregnancy was affected by BDs (including NTDs and congenital heart defects) demonstrated that, in early pregnancy, adequate nutrition (i.e., eating meat, fresh vegetables, fruit more than once a week) was a protective factor, while eating germinated potatoes was a risk factor. The geometrical mean (p5-p95) of serum folic acid in women with NTD birth defects was 9.6 nmol/L (3.6, 23.03), which was significantly lower than that in normal women (14.03 nmol/L).

CONCLUSION

Women of childbearing age in the two counties of Shanxi Province, China, have a marked insufficient intake of some nutrients, especially folic acid, zinc, vitamins A and B12. This nutrient deficiency may be an important risk factor for the high prevalence of birth defects in these regions. Therefore, adequate dietary nutrition in early pregnancy can prevent BDs.

An exceptionally low percentage of Thai expectant mothers and medical personnel with folic acid knowledge and peri-conceptional consumption urges an urgent education program and/or food fortification

It has been widely accepted that peri-conceptional consumption of folic acid (FA) can prevent many congenital anomalies, including more than one-half of all neural tube defects. In several developed countries, educational campaigns and/or food fortification with FA have been launched, resulting in lower incidences of some anomalies. In Thailand, congenital anomalies preventable by FA are still an important public health problem. However, there have been no recommendations on the use of FA supplementations from the health authorities. In order to achieve a goal of reducing the diseases' incidences, our initial effort is to assess knowledge and use of peri-conceptional FA. We conducted a questionnaire survey of 500 pregnant women and 500 child-bearing-age female medical personnel in the King Chulalongkorn Memorial Hospital from June 2003 through December 2003. Of the 383 pregnant women who completed the survey, 23.5% (90/383) knew that FA helped to prevent birth defects, 3.4% (13/383) knew that FA should be taken before pregnancy, and only 0.3% (1/383) reported taking FA before pregnancy. Among the 422 female medical personnel who completed the survey, 84.4% (356/422) knew that FA could prevent birth defects, whereas 40.0% (169/422) knew that FA should be taken prior to pregnancy. This study provided strong evidence that educational campaigns and/or food fortification are urgently needed.

Critical relationship between sodium valproate dose and human teratogenicity: results of the Australian register of anti-epileptic drugs in pregnancy

To compare the incidence of foetal malformations (FMs) in pregnant women with epilepsy treated with different anti-epileptic drugs (AED) and doses, and the influence of seizures, family and personal history, and environmental factors. A prospective, observational, community-based cohort study.

METHODS

A voluntary, Australia-wide, telephone-interview-based register prospectively enrolling three groups of pregnant women: taking AEDs for epilepsy; with epilepsy not taking AEDs; taking AEDs for a non-epileptic indication. Four hundred and fifty eligible women were enrolled over 40 months. Three hundred and ninety six pregnancies had been completed, with 7 sets of twins, for a total of 403 pregnancy outcomes.

RESULTS

354 (87.8%) pregnancy outcomes resulted in a healthy live birth, 26 (6.5%) had a FM, 4 (1%) a death in utero, 1 (0.2%) a premature labour with stillbirth, 14 (3.5%) a spontaneous abortion and 4 lost to follow-up. The FM rate was greater in pregnancies exposed to sodium valproate (VPA) in the first trimester (16.0%) compared with those exposed to all other AEDs (16.0% vs. 2.4%, P < 0.01) or no AEDs (16.0% vs. 3.1%, [Formula: see text] ). The mean daily dose of VPA taken in pregnancy with FMs was significantly greater than in those without (1,975 vs. 1,128 mg, P < 0.01). The incidence of FM with VPA doses >or= 1,100 mg was 30.2% vs. 3.2% with doses <1,100 mg (P <0.01).

CONCLUSIONS

There is a dose-effect relationship for FM and exposure to VPA during the first trimester of pregnancy, with higher doses of VPA associated with a significantly greater risk than with lower doses or with other AEDs. These results highlight the need to limit, where possible, the dose of VPA in pregnancy.

Simultaneous quantification of 11 pivotal metabolites in neural tube defects by HPLC-electrospray tandem mass spectrometry

One-carbon metabolism that involves folate metabolism and homocysteine metabolism plays a powerful role in embryonic development. Any impairment to this metabolism during the neurulation process would trigger the occurrence of neural tube defects (NTDs). The great importance of one-carbon metabolism necessitates the establishment of methodology to determine the relative compounds involved in the metabolic cycles. We have developed a sensitive method for measurement of 11 pivotal compounds by using high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) in sera of pregnant women. Use of an aqueous chromatography column increased retention time and separation of the polar compounds in the system, resulting in fewer co-elution and interference from the other compounds that can lead to ion suppression. Calibration curves suitable for the analysis of maternal serum were linear (r(2)>0.997) with limits of detection from 0.05 to 1ng/mL. Intra-day coefficients of variation (CVs) and inter-day CVs were both lower than 11%. With the developed method, 96 serum samples including 46 cases and 50 controls were analyzed. The established method provided a reliable method for quantifying most of the compounds involved in the one-carbon metabolism simultaneously, thus made it possible to elucidate NTDs with multiple factors instead of one single and provided a solid foundation for the diagnosis and prevention of NTDs as well as some other one-carbon metabolism related diseases.

Folic acid fortification and supplementation--good for some but not so good for others

Evidence has established the protective effect of folic acid (FA) fortification and periconceptional supplementation on neural tube defects (NTDs). Folic acid fortification and periconceptional supplementation of women may reduce the risk of certain childhood cancers in their offspring. However, recent human studies have suggested that FA supplementation and fortification may promote the progression of already existing, undiagnosed, preneoplastic and neoplastic lesions, thereby corroborating earlier observations from animal and in vitro studies. Following the success of mandatory FA fortification on the reduction of NTD rates in the United States and Canada, several countries are currently considering whether or not, and at what dose, to institute FA fortification. Future debates and decisions regarding FA fortification should take into consideration all potential adverse effects and dose-responses of such a measure because it may be associated with very serious consequences for many generations. In addition to careful monitoring of adverse effects, preclinical and population-based studied are warranted in order to determine the efficacy, safety, and potential deleterious effects of FA fortification and supplementation on cancer risk and other health outcomes.

Food fortification with folic acid: has the other shoe dropped?

Folic acid (FA) supplementation effectively reduces the rates of children born with neural tube defects (NTDs). Currently, 42 nations practice mandatory FA fortification to combat NTD. In addition to NTD, FA fortification may also have salutary effects on the incidence of orofacial cleft birth defects and have secondary benefits in reducing serum homocysteine concentrations and stroke mortality. However, a recent note of caution has been raised concerning a possible negative effect of mandatory FA fortification on the incidence of colorectal cancer.