Effects of folic acid supplementation during different pregnancy periods and relationship with the other primary prevention measures to neural tube defects

Objective: To find out the prevention effects of folic acid supplements during different pregnancy periods on neural tube defects (NTDs) and the relationship of folic acid supplements with the other NTDs’ primary preventive measures.

Methods: A 1:1 case-control study was conducted. Four hundred and fifty-nine women who delivered or gestate infants/fetuses with NTDs in the last two years were randomly selected as cases and were matched with women who delivered babies without obvious birth defects as controls.

Results: For anencephaly, folic acid supplementation during the periconceptional period and preconceptional period has a 57–83% reduction in risk of NTDs(ORs ranged from 0.17 to 0.43). For spina bifida, folic acid supplementation during the periconceptional period has a 79% reduction in risk of NTDs (OR?=?0.21). For encephalocele, folic acid supplementation during the periconceptional period has a 67% reduction in risk of NTDs (OR?=?0.33). The prevention effects on NTDs were significant when these preventive measures combined with folic acid supplements during the periconceptional period, with OR 0.04, 0.07, 0.10 and 0.11.

Conclusion: The specific effects of folic acid supplementation during different periods show the reduction in the risk of NTDs, anencephaly, spina bifida, encephalocele. During periconceptional period, folic acid supplements have preventive effects on all NTDs’ subtypes.     

Randomized trial of a physician-based intervention to increase the use of folic acid supplements among women

OBJECTIVE: Fewer than one third of American women take folic acid daily, although many women report that they would take folic acid if their physicians advised them to do so. This study determined the impact of a physician intervention during routine gynecologic visits on folic acid supplementation. STUDY DESIGN: Patients were assigned randomly to receive brief folic acid counseling, a reminder phone call, and 30 folic acid tablets (n = 162 women; intervention group) or to receive counseling about other preventive health behaviors and a folic acid informational pamphlet (n = 160 women; control group). Self-reported folic acid use was compared at baseline and at 2 months. RESULTS: Of the 279 patients who completed the study, weekly folic acid intake increased in the intervention group by 68%, compared with 20% in the control group ( P =.008). No significant differences were found in daily intake. The women who were most influenced by the intervention were black and lower income and not planning pregnancies. CONCLUSION: With little effort expended to encourage folic acid use, gynecologists could potentially reduce the risk of folate-preventable birth defects among their patients by as much as 11%.     

Awareness of the role of folic acid, dietary folate intake and plasma folate concentration in Japan

AIM: To investigate awareness of the role of folic acid in the prevention of neural tube defects, dietary intake of folate, and plasma folate concentration. METHODS: Postal questionnaires were collected from 1190 lay female subjects in three different groups and from seven groups of 3067 health-care providers. Dietary folate was investigated by assessing food frequency charts that were kept for 3 days by 245 women, and plasma folate was assessed by analyzing the blood serum of 194 women. RESULTS: Less than 15% of citizens and mothers who had live births knew that there was a link between folic acid and neural tube defects. The exception was with myelodysplastic families, in which awareness was 92%. Awareness among health-care professionals was generally low. The highest level was found in obstetricians-gynecologists (76%) and the lowest in nurses (12%). Dietary folate intake and plasma concentration were highest in pregnant women (356 microg/day and 11.9 ng/mL) and the lowest in student nurses (217 microg/day and 6.8 ng/mL). When the recommended dietary allowance of folate in Japan is taken into consideration, 22% of the non-pregnant women and 71% of the pregnant women did not fulfill the recommended dietary allowance. CONCLUSIONS: Information on the role of periconceptional intake of folic acid is not sufficiently disseminated to young women and health-care professionals alike. Pregnant women should be repeatedly recommended to take folic acid supplements of 400 microg/day.     

The Prevention of Congenital Anomalies with Periconceptional Folic Acid Supplementation

Large randomized trials have demonstrated the critical role of folic acid supplementation in the prevention of neural tube defects. Since 1992, a number of national and international professional societies have released guidelines recommending folic acid supplementation of at least 0. 4 mg/day for all women of childbearing age or women planning pregnancies, and 4 mg/day for women with a previous infant with a neural tube defect. Furthermore, a reduction in the incidence of congenital cardiac and urologie anomalies has been demonstrated in some studies following periconceptional folic acid supplementation. There is growing evidence of a possible role of folic acid supplementation in the prevention of other congenital anomalies, including cardiac defects. Since 1998, mandatory fortification of certain foods with folate has been associated with at least a 54% reduction in the incidence of open neural tube defects, yet rates of periconceptional folic acid use remain suboptimal, especially in minority women. Innovative strategies in educating women, health-care providers, and pharmacists on the benefits of folic acid supplementation need to be explored. Mandatory folate fortification of foods needs to be defined and monitored.     

Inadequate compliance with periconceptional folic acid supplementation in South Australia

BACKGROUND: Despite recommendations for women to take folic acid supplements, there has been little reduction in the number of neural tube defect cases occurring each year. AIMS: To assess the level of compliance of pregnant women to recommendations for folic acid supplementation in South Australia, and audit the labelled content in reported supplements used. METHODS: A survey was conducted from May to September 2005 with 304 pregnant women recruited from antenatal clinics at the Lyell McEwin Health Service, the Women's and Children's Hospital and the Modbury Hospital in Adelaide. RESULTS: Full compliance with supplementation recommendations for both timing and dose was achieved by 30% of women. Partial compliance was achieved by 43%, while 27% took no folic acid supplements. CONCLUSIONS: There is currently poor compliance with folic acid supplementation around conception. Additional food fortification may better achieve an adequate daily level of folic acid.     

Folic acid prevents neural tube defects: international comparison of awareness among obstetricians/gynecologists and urologists

AIM: It has been suggested that periconceptional intake of folic acid prevents risks of having fetuses afflicted with neural tube defects. We aim to internationally investigate knowledge of the role of folic acid and attitudes toward the life-style of young women of child-bearing age among obstetricians/gynecologists and urologists. METHODS: A questionnaire was sent to obstetricians/gynecologists and urologists residing in Japan, South Korea, Taiwan, North America, Europe, Australia and New Zealand by post or e-mail. The investigation was conducted between December 2002 and November 2004. RESULTS: A mean of 91% of obstetricians/gynecologists and 56% of urologists are aware of the role of folic acid, where Asian urologists knew less compared to those of North America, Europe, Australia and New Zealand. A majority of doctors always, or occasionally, recommend folic acid supplements or multivitamins, well-balanced meals, and the cessation of smoking and drinking. An average of 85% of doctors believes information on folic acid should be disseminated to young women. CONCLUSIONS: A majority of obstetricians/gynecologists and urologists know the importance of periconceptional folic acid in reducing the risk of neural tube defects and have been advising young women to improve their lifestyle.     

Folic acid in pregnancy

For more than two decades, folic acid supplementation has been an essential component of pre-pregnancy and early pregnancy care across the world. Folic acid supplements reduce the risk of fetal neural tube defects, and a decline in incidence of such defects following food fortification with folic acid has been a public health success story in many countries. Recent evidence has shown that some group of women, such as those who are obese or taking certain medications, are at an increased risk of fetal neural tube anomalies and require a higher dose of periconceptional folic acid supplementation. Although concerns have been raised over the possible risk of cancer with increased folic acid intake, most data from large studies appear reassuring.     

Antiepileptic drug use, folic acid supplementation, and congenital abnormalities: a population-based case-control study

Objective  To investigate whether folic acid supplementation in early pregnancy modifies the association between the prevalence of congenital abnormalities in the offspring and maternal use of carbamazepine (CBZ), phenobarbital (PB), phenytoin (PHT), and primidone (PRI).
Design  A population-based case–control study.
Setting  The Hungarian Case–Control Surveillance of Congenital Abnormalities (HCCSCA) (1980–1996) and its information on children from the Hungarian Congenital Abnormality Registry and the Hungarian National Birth Registry.
Population  Children with congenital abnormalities (cases; n = 20 792, of whom 148 had been exposed to antiepileptic drugs [AEDs]) and unaffected children (controls; n = 38 151, of whom 184 had been exposed to AEDs).
Methods  Information on drug exposure and background variables for the mothers were collected from antenatal logbooks, discharge summaries, and structured questionnaires completed by the mothers at the time of HCCSCA registration.
Main outcome measures  Congenital abnormalities detected at termination of pregnancy, at birth or until 3 months of age according to CBZ, PB, PHT, or PRI exposure at 5–12 weeks from first day of the last menstrual period (LMP), stratified by folic acid supplementation.
Results  Compared with children unexposed to AEDs and folic acid, the odds ratio of congenital abnormalities was 1.47 (95% CI 1.13–1.90) in children exposed to AEDs without folic acid supplementation and 1.27 (95% CI 0.85–1.89) for children exposed to AEDs with folic acid supplementation.
Conclusion  The results indicate that the risk of congenital abnormalities in children exposed in utero to CBZ, PB, PHT, and PRI is reduced but not eliminated by folic acid supplementation at 5–12 weeks from LMP. The statistical precision in our study is limited due to rarity of the exposures, and further studies are needed.     

Awareness of the benefits of folic acid and prevalence of the use of folic acid supplements to prevent neural tube defects among Thai women

Objective To determine the level of knowledge about the usefulness of periconceptional folic acid supplementation among pregnant women. Materials and methods An anonymous questionnaire was completed by selected subjects to assess folic acid awareness. The questionnaire was administered to pregnant women who were seeking antenatal care at King Chulalongkorn Memorial Hospital May to December 2005. The questions covered their knowledge and use of folic acid supplements, pregnancy intention, and demographic and socioeconomic characteristics. Results Out of 401 women surveyed, 76.1% of them reported that they had heard of folate. Of these, only 24.4% of the total subjects knew that folate was something important. Overall, 9.7% of the total women took folic acid during periconceptional period. The most common information sources on folate were the media. Logistic regression analysis showed that education of mother was the strongest predictor of having taken folic acid during the correct period. Conclusion Although some pregnant women are aware of the need to take folic acid, the actual impact of the present recommendations is almost negligible. Information to specifically inform patients about the need to take folic acid to prevent neural tube defects by medias and healthcare personnel seem to improve the final intake of folic acid during the protective period.     

Periconceptional folic acid supplementation among women attending antenatal clinic in Anhui, China: data from a population-based cohort study

Objectives

to examine the rate of periconceptional and optimal folic acid supplementation, and to characterise their patterns and determinants among antenatal women in central China.

Design

data from 4290 women in the Anhui Birth Defects and Child Development Cohort Study recruited between October 2008 and September 2009 were analysed.

Setting

seven Maternal and Child Health Centres of two cities (Hefei and Maanshan) in Anhui province of central China.

Participants

women initiating prenatal care were included and asked to complete a structured questionnaire regarding folic acid supplementation.

Findings

sixty-eight per cent (2905/4290) of pregnant women reported taking folic acid supplementation periconceptionally (i.e. at some point before or during early pregnancy), and 32.8% (1405/4290) and 65.2% (2797/4290) had taken it before or during early pregnancy, respectively. However, only 16.1% (690/4290) used it optimally (i.e. regularly from four weeks before pregnancy throughout four weeks after pregnancy). Use of periconceptional folic acid was significantly associated with educational level, household income, registered residence, age, gestational age at recruitment, and planning of pregnancy.

Conclusion

optimal folic acid supplementation was relatively low.

Implications for practice

further efforts are needed to inform the population and promote the use of folic acid supplementation.     

Periconceptional factors affect the risk of neural tube defects in offspring: a hospital-based case-control study in China

Abstract

Objective: To explore the periconceptional factors affecting the risk of neural tube defects (NTDs), we carried out a hospital-based case-control study in China.

Methods: A 1:1 matched case-control study was conducted. With self-designed questionnaires, we solicited relevant information from 459 case mothers and 459 control mothers selected in two provinces of China through face-to-face interviews. Univariate and multivariate conditional logistic regression analyses were conducted to evaluate the effect values by odds ratios (ORs) and 95% confidence intervals (95%CIs) with SAS9.1.3.software.

Results: Daily passive tobacco smoke exposure was a risk factor for total NTDs (OR?=?8.688, 95%CI?=?2.329–32.404). Diet adjustment in the first trimester (OR?=?0.061, 95%CI?=?0.014–0.274), periconceptional folic acid intake (OR?=?0.059, 95%CI?=?0.011–0.321) and health education (OR?=?0.251, 95%CI?=?0.081–0.781) were protective factors for total NTDs. Differences in factors and their effects on NTDs were found for the three subtypes of NTDs: anencephaly, spina bifida and encephalocele.

Conclusions: Daily passive tobacco smoke exposure, diet adjustment in the first trimester, periconceptional folic acid intake and health education were associated with NTDs.     

Trends and predictors of folic acid awareness and periconceptional use in pregnant women

OBJECTIVE: The purpose of this study was to describe recent trends in folic acid awareness and use in the periconceptional period among pregnant women in relation to maternal sociodemographic and other relevant factors. STUDY DESIGN: From 1988 to 2002, 16,555 women from the Slone Epidemiology Center Birth Defects Study were interviewed about medication use before and during pregnancy (which included multivitamins and folic acid), about whether they were aware of any vitamins that might decrease the risk of birth defects, and about sociodemographic and medical factors. RESULTS: Awareness of folic acid benefits increased from 0 in 1988 to 50% in 1996 and thereafter. The use of folic acid in the periconceptional period increased from 15% in 1988 to 40% in the last few years. Maternal education was a strong independent predictor of both awareness and use as were ethnicity, whether the pregnancy was wanted, family income, and whether a health care provider was consulted before planning. CONCLUSION: Promoting the use of folic acid supplements, particularly among these disadvantaged groups, is essential to further decrease the prevalence of neural tube defects.     

The regional campaign for women on awareness of neural tube defects and folic acid in Narlidere,Izmir: a community-based intervention

Objectives To create an awareness among women and to update the knowledge of health personnel about neural tube defects (NTDs) and folate in order to reduce the incidence of NTD in Narlidere, ?zmir.

Methods In 2006, a regional campaign was organized in Narlidere, Izmir that aimed at informing women of child-bearing age on folic acid and prevention of NTD. Nearly 4400 women participated in the study. By means of questionnaires the level of knowledge before and after the intervention was evaluated.

Results Before the campaign was carried out, 18% of women had heard of folic acid. Their level of knowledge increased after the campaign (p < 0.0001). Post-intervention scores of high school and university graduates and women with high or middle income, as well as those having a friend or kin with spina bifida were found to have significantly improved.

Conclusions The pilot community-based training programme was very successful. Similar programmes, integrated within routine health care services, promoting the use of folic acid will be fostered in the whole country.