Awareness and Use of Folic Acid Among Women in the Lower Mississippi Delta

Effects and safety of periconceptional oral folate supplementation for preventing birth defects

BACKGROUND

It has been reported that neural tube defects (NTD) can be prevented with periconceptional folic acid supplementation. The effects of different doses, forms and schemes of folate supplementation for the prevention of other birth defects and maternal and infant outcomes are unclear.

OBJECTIVES

This review aims to examine whether periconceptional folate supplementation reduces the risk of neural tube and other congenital anomalies (including cleft palate) without causing adverse outcomes in mothers or babies. This is an update of a previously published Cochrane review on this topic.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 August 2015). Additionally, we searched the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (31 August 2015) and contacted relevant organisations to identify ongoing and unpublished studies.

SELECTION CRITERIA

We included all randomised or quasi-randomised trials evaluating the effect of periconceptional folate supplementation alone, or in combination with other vitamins and minerals, in women independent of age and parity.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility of studies against the inclusion criteria, extracted data from included studies, checked data entry for accuracy and assessed the risk of bias of the included studies. We assessed the quality of the body of evidence using the GRADE approach.

MAIN RESULTS

Five trials involving 7391 women (2033 with a history of a pregnancy affected by a NTD and 5358 with no history of NTDs) were included. Four comparisons were made: 1) supplementation with any folate versus no intervention, placebo or other micronutrients without folate (five trials); 2) supplementation with folic acid alone versus no treatment or placebo (one trial); 3) supplementation with folate plus other micronutrients versus other micronutrients without folate (four trials); and 4) supplementation with folate plus other micronutrients versus the same other micronutrients without folate (two trials). The risk of bias of the trials was variable. Only one trial was considered to be at low risk of bias. The remaining studies lacked clarity regarding the randomisation method or whether the allocation to the intervention was concealed. All the participants were blinded to the intervention, though blinding was unclear for outcome assessors in the five trials.The results of the first comparison involving 6708 births with information on NTDs and other infant outcomes, show a protective effect of daily folic acid supplementation (alone or in combination with other vitamins and minerals) in preventing NTDs compared with no interventions/placebo or vitamins and minerals without folic acid (risk ratio (RR) 0.31, 95% confidence interval (CI) 0.17 to 0.58); five studies; 6708 births; high quality evidence). Only one study assessed the incidence of NTDs and showed no evidence of an effect (RR 0.07, 95% CI 0.00 to 1.32; 4862 births) although no events were found in the group that received folic acid. Folic acid had a significant protective effect for reoccurrence (RR 0.34, 95% CI 0.18 to 0.64); four studies; 1846 births). Subgroup analyses suggest that the positive effect of folic acid on NTD incidence and recurrence is not affected by the explored daily folic acid dosage (400 µg (0.4 mg) or higher) or whether folic acid is given alone or with other vitamins and minerals. These results are consistent across all four review comparisons.There is no evidence of any preventive or negative effects on cleft palate (RR 0.73, 95% CI 0.05 to 10.89; three studies; 5612 births; low quality evidence), cleft lip ((RR 0.79, 95% CI 0.14 to 4.36; three studies; 5612 births; low quality evidence), congenital cardiovascular defects (RR 0.57, 95% CI 0.24 to 1.33; three studies; 5612 births; low quality evidence), miscarriages (RR 1.10, 95% CI 0.94 to 1.28; five studies; 7391 pregnancies; moderate quality evidence) or any other birth defects (RR 0.94, 95% CI 0.53 to 1.66; three studies; 5612 births; low quality evidence). There were no included trials assessing the effects of this intervention on neonatal death, maternal blood folate or anaemia at term.

AUTHORS' CONCLUSIONS

Folic acid, alone or in combination with vitamins and minerals, prevents NTDs, but does not have a clear effect on other birth defects.

Plasma folate levels in early to mid pregnancy after a nation-wide folic acid supplementation program in areas with high and low prevalence of neural tube defects in China

BACKGROUND

Folic acid supplementation is recommended for all women of child-bearing age to prevent neural tube defects (NTDs). A nation-wide folic acid supplementation program was implemented in rural areas of China since 2009; however, changes in plasma folate levels in pregnant women were unknown.

METHODS

A cross-sectional survey was conducted in 2011 to 2012, with 1736 pregnant women enrolled, and results were compared with a previous survey in 2002 to 2004. A microbiological method was used to determine plasma folate levels. Preprogram and postprogram median plasma folate concentrations were compared while stratified by prevalence of NTDs and residence.

RESULTS

In the high NTD prevalence population, plasma folate concentration increased to 33.4 (18.7, 58.4) nmol/L in the postprogram sample, which is 2.9 times of the preprogram. In the low NTD prevalence population, plasma folate increased to 67.9 (44.5, 101.9) nmol/L, which is 1.9 times of the preprogram. Gaps remained in plasma folate levels with respect to prevalence of NTDs and residence. Folic acid supplementation has a strong impact on plasma folate concentrations. Earlier supplementation (before the last menstrual period), increased supplementation frequency and more total days of supplementation were associated with a higher plasma folate concentration as demonstrated in both the high- and low-prevalence populations.

CONCLUSION

Plasma folate levels among pregnant Chinese women increased dramatically after the nation-wide folic acid supplementation program in both rural and urban areas, and in populations of high and low NTD prevalence. The nation-wide program should have a component to ensure that supplementation begins before pregnancy.

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

OBJECTIVE

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

DESIGN

Two cross-sectional surveys were conducted.

SETTING

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

SUBJECTS

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

RESULTS

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

CONCLUSIONS

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

Effects and safety of periconceptional folate supplementation for preventing birth defects

BACKGROUND

It has been reported that neural tube defects can be prevented with periconceptional folic acid supplementation. The effects of different doses, forms and schemes of folate supplementation for the prevention of other birth defects and maternal and infant outcomes are unclear.

OBJECTIVES

This review updates and expands a previous Cochrane Review assessing the effects of periconceptional supplementation with folic acid to reduce neural tube defects (NTDs). We examined whether folate supplementation before and during early pregnancy can reduce neural tube and other birth defects (including cleft palate) without causing adverse outcomes for mothers or babies.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (July 2010). Additionally, we searched the international clinical trials registry platform and contacted relevant organisations to identify ongoing and unpublished studies.

SELECTION CRITERIA

We included all randomised or quasi-randomised trials evaluating the effect of periconceptional folate supplementation alone, or in combination with other vitamins and minerals, in women independent of age and parity.

DATA COLLECTION AND ANALYSIS

We assessed trials for methodological quality using the standard Cochrane criteria. Two authors independently assessed the trials for inclusion, one author extracted data and a second checked for accuracy.

MAIN RESULTS

Five trials involving 6105 women (1949 with a history of a pregnancy affected by a NTD and 4156 with no history of NTDs) were included. Overall, the results are consistent in showing a protective effect of daily folic acid supplementation (alone or in combination with other vitamins and minerals) in preventing NTDs compared with no interventions/placebo or vitamins and minerals without folic acid (risk ratio (RR) 0.28, 95% confidence interval (CI) 0.15 to 0.52). Only one study assessed the incidence of NTDs and the effect was not statistically significant (RR 0.08, 95% CI 0.00 to 1.33) although no events were found in the group that received folic acid. Folic acid had a significant protective effect for reoccurrence (RR 0.32, 95% CI 0.17 to 0.60). There is no statistically significant evidence of any effects on prevention of cleft palate, cleft lip, congenital cardiovascular defects, miscarriages or any other birth defects. There were no included trials assessing the effects of this intervention on maternal blood folate or anaemia at term.We found no evidence of short-term side effects.

AUTHORS' CONCLUSIONS

Folic acid, alone or in combination with vitamins and minerals, prevents NTDs but does not have a clear effect on other birth defects.

Occurrence of conotruncal heart birth defects in Texas: a comparison of urban/rural classifications

PURPOSE

(1) Determine if there is an association between 3 conotruncal heart birth defects and urban/rural residence of mother. (2) Compare results using different methods of measuring urban/rural status.

METHODS

Data were taken from the Texas Birth Defects Registry, 1999-2003. Poisson regression was used to compare crude and adjusted birth prevalence.

FINDINGS

Based on residences of births in Texas, the values for urban influence code (UIC), rural urban continuum code (RUCC), and rural urban commuting area (RUCA) were highly correlated with each other and, less highly, to percentage of land in crops. For tetralogy of Fallot, the most rural category consistently showed the highest prevalence ratio for all measures. The adjusted prevalence ratio for highest percentage cropland was 1.73 [95% CI, 1.14-2.51] using natural breaks and 1.42 [95% CI, 1.07-1.86] using quartiles. The trend with cropland percentage was significant (P < .03), whether crude or adjusted. The crude trend was also significant using RUCC. Neither truncus arteriosus nor transposition of the great arteries exhibited consistent associations with urban or rural residence.

CONCLUSIONS

The urban/rural measures were generally correlated with each other; as a broad measure, RUCA has advantages for many health studies. Tetralogy of Fallot was most prevalent in rural areas; that pattern was strongest using percentage of land in crops.

Awareness, knowledge, and use of folic acid among women: a study from Turkey

PURPOSE

To investigate the awareness, knowledge, and behaviors relevant to folic acid intake in women aged 15-49 years.

MATERIALS AND METHODS

A questionnaire designed by the researchers was administered to 1,083 women who attended to family health care centers for any reason, between 1 and 15 of December 2009.

RESULTS

Half of the women (53.7%) surveyed did not hear or read about folic acid. Women older than 35 and less-educated women were more unaware of folic acid. Out of 171 pregnant women, 81.3% (139 women) were taking/took vitamin/folic acid supplementation but only 12.2% of the users started to take supplements at least 1 month before conception. Out of 912 non-pregnant women 81 (8.9%) said they are taking any vitamin or mineral supplement. Out of the women who are not pregnant, not using a modern contraceptive method and planning to have a child at the time of the survey, only 9 (10%) were taking vitamin/folic acid. The most common information sources on folic acid were the doctors.

CONCLUSION

In order to improve the intake of folic acid during the recommended period, preconceptional counseling by the family doctors to inform women of childbearing age about the need to take folic acid to prevent NTDs seems to be important.

Urban-rural residence and the occurrence of cleft lip and cleft palate in Texas, 1999-2003

PURPOSE

The etiology of orofacial clefts is complex and relatively unknown. Variation in cleft lip with or without palate (CLP) and cleft palate alone (CP) was examined in Texas across urban-rural residence (1999 to 2003).

METHODS

Cases came from the Texas Birth Defects Registry (1,949 CLP and 1,054 CP) and denominator data came from vital records (254 counties; 1,827,317 live births). Variation in maternal residence was measured using four classification schemes: Rural Urban Continuum Codes, Urban Influence Codes, percentage of county in cropland, and Rural Urban Commuting Areas. Poisson regression was used to calculate rate ratios, adjusted for infant sex, plurality, gestational age, maternal parity, age, race/ethnicity, and education.

RESULTS

Compared to the most urban referent category, living in more rural areas was associated with an increased adjusted risk of CLP. For example, the Rural-Urban Continuum Codes demonstrated elevated risks for CLP in "thinly populated areas" compared to "metropolitan-urban areas" (adjusted prevalence ratio = 1.9; 95% confidence intervals (CI) 1.2-2.8); CP was not similarly associated. Percentage of county cropland was not consistently associated with any outcome.

CONCLUSION

The association patterns between non-urban residence and risk of CLP, except for percentage of cropland, suggests a constellation of exposures that may differ across urban-rural residence.

Urban-rural residence and the occurrence of neural tube defects in Texas, 1999-2003

Neural tube birth defects (NTDs) affect more than 4000 pregnancies in the US annually. The etiology of NTDs is believed to be multifactorial, but much remains unknown. We examined the pattern and magnitude of urban-rural variation in anencephaly, spina bifida without anencephaly, and encephalocele in Texas in relation with urban-rural residence for the period 1999-2003. There was no evidence that urban-rural residence was associated with changes in the rate of anencephaly or spina bifida without anencephaly in unadjusted or adjusted analyses. In contrast, rates of encephalocele were statistically significantly higher in areas classified as suburban or more rural compared to urban areas using four different urban-rural residence indicators.

Assessing awareness, knowledge and use of folic acid in Kansas women between the ages of 18 and 44 years

Taking folic acid daily, before and during early pregnancy, has been proven to reduce neural tube birth defects (NTD). Unfortunately, many women fail to take it daily as recommended.

OBJECTIVES

To assess women's self-reported awareness, knowledge and use of folic acid. Methods Data were obtained by cross-sectional, random digit-dialing, computer-assisted telephone interviews with 250 women in Kansas. Associations were determined by chi-squared analysis.

RESULTS

Eighty-eight percent of childbearing age women in Kansas have a general awareness of folic acid, 20% have knowledge that it reduces birth defects, but only 25% report taking it daily. Awareness was associated with high school or greater education (P < .0001), incomes over $25,000 (P = 0.0003), being married (P = 0.0035), being white (P = 0.0135), having health insurance (P = 0.0152) and being capable of pregnancy (P = 0.0119). Knowledge that folic acid reduces birth defects was associated with being aware of the USPHS recommendation (P < .0001), being capable of pregnancy (P = 0.0043), being pregnant (P = 0.0061), and being aware of folic acid (P = 0.0379). Taking folic acid daily was associated with currently being pregnant (P = 0.0126).

CONCLUSIONS

Women less likely to take folic acid on a daily basis were young, non-Caucasians who reported less education, less income and no health insurance. Based upon these data, multi-level education campaigns that specifically target lower-SES women should be considered.