Correlates of intake of folic acid–containing supplements among pregnant women

doi:10.1016/j.ajog.2005.06.018

American Journal of Obstetrics and Gynecology

Volume 194, Issue 1, January 2006, Pages 203-210

https://doi.org/10.1016/j.ajog.2005.06.018 Get rights and content

Objective

This study describes the timing and correlates of folic acid supplement intake among pregnant women.

Study design

Data from 2518 women with estimated delivery dates from 1997 to 2000, collected for the National Birth Defects Prevention Study, a population-based case-control study, were analyzed. Multinomial logistic regression was used to identify correlates of supplement intake.

Results

Fifty-three percent of women began taking folic acid supplement during the periconceptional period, 35% during early pregnancy, and 8% during late pregnancy (ie, 3 months before through 1 month after conception, 2-3 months after conception, or more than 3 months after conception, respectively). Women who did not take folic acid supplement periconceptionally tended to be nonwhite, speak Spanish, have low education, be younger than 25 years old, be nulliparous, smoke, have no previous miscarriage and no fertility treatments, begin prenatal care and become aware of their pregnancy after the first trimester, have nonplanned pregnancies, and eat less breakfast cereal.

Conclusion

This study identifies correlates of folic acid supplement intake, which may contribute to the design of interventions to improve intake during early pregnancy.

Section snippets

Material and methods

This study included data on deliveries that had estimated due dates from October 1997 to December 2000 and were part of the National Birth Defects Prevention Study.¹⁷ This study is an approved activity of the institutional review boards of the participating study centers and the Centers for Disease Control and Prevention. Each study site randomly selected approximately 100 nonmalformed, liveborn controls per study year from birth certificates (Iowa, Massachusetts, and New Jersey) or birth

Results

Among the 2518 women interviewed, 53% (1324) began taking FA supplements before or during the periconceptional period, 35% (879) during early pregnancy, and 8% (208) during late pregnancy, such that overall, 96% (2411) took FA supplements at some time during the 3 months before pregnancy or during pregnancy (Table I). Two percent of the women (39) took only non–FA-containing supplements, and 3% (68) took no supplements during this time period. Among women who took FA supplements, 94% (2256)

Comment

This study indicates that most (96%) women from several regions of the United States took FA supplements during pregnancy. However, only 53% took FA around the time of neural tube closure, which is completed by 4 weeks after conception.

Women who were not taking FA supplements during the first few weeks after conception (ie, the periconceptional period) tended to be nonwhite and younger than 25 years old, have low education, begin prenatal care and become aware of their pregnancy after the first

Acknowledgment

We thank Kathy Kelley, RPh, for her contributions to coding the data on the supplements.

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Maternal periconceptional use of multivitamins and reduced risk for conotruncal heart defects and limb deficiencies among offspring
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Maternal supplemental and dietary zinc intake and the occurrence of neural tube defects in California
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Folic acid supplement use and the risk of gestational hypertension and preeclampsia
2018, Women and Birth
Citation Excerpt :
For instance, a study using data from the 2001 to 2002 National Health and Nutrition Examination Survey showed that a lower percentage of Hispanic women consumed the recommended dosage of folic acid from supplements and fortified foods compared to non-Hispanic White women.28 However, it should also be noted that a majority of women included in the study had characteristics, such as higher educational achievement, which have been shown to correlate with higher use of folic acid supplements.29,30 Further limitations, such as the high rates of comorbidities and possible selection bias, could limit generalizability of the study.
Hypertensive disorders of pregnancy are among the leading causes of maternal morbidity and mortality. Studies suggest that the use of folic acid may lower the risk of hypertensive disorders in pregnant women.
The aim of this study was to assess the effects of timing and duration of folic acid-containing supplement use on the risk for gestational hypertension and preeclampsia.
Exposures and outcomes data were obtained through interviews and review of participant’s medical records from the MotherToBaby cohort studies across the United States and Canada. Demographics, medical history, lifestyle factors, substance use, and fetal sex were assessed as potential confounders. Unadjusted and adjusted risks for gestational hypertension and preeclampsia were examined using odds ratios and 95% confidence intervals.
3247 women were included in the study. Compared to non-supplement use, early and late supplement use were not significantly associated with the development of gestational hypertension or preeclampsia. The odds of developing gestational hypertension and preeclampsia were significantly reduced as the duration of folic acid-containing supplement use increased.
Findings from this study suggest that the use of folic acid-containing supplements may mitigate the risk for gestational hypertension and preeclampsia.
Epidemiological Factors in Developmental Toxicology
2018, Comprehensive Toxicology: Third Edition
Human experience is the ultimate test of risks for human congenital anomalies following exposures during pregnancy. The gold standard for human safety studies is the randomized clinical trial. However, due to ethical constraints, only in few instances it is possible to conduct such trials to evaluate the teratogenicity of a specific exposure. Various types of observational epidemiological studies provide the major source of information regarding human teratogenicity. There are numerous methodological challenges in conducting studies of prenatal exposures in relation to rare outcomes such as birth defects, and each of the commonly used study designs has limitations. Therefore, for many exposures in pregnancy, the available data are limited in quantity and quality. Multiple types of study designs are needed to appropriately evaluate exposures. A systematic program for collecting these data and a coordinated plan for interpretation is recommended.
Periconceptional folic acid supplementation among women attending antenatal clinic in Anhui, China: Data from a population-based cohort study
2012, Midwifery
Citation Excerpt :
A case-control study (de Jong-Van den Berg et al., 2005), based on data from Boston, Philadelphia, and Toronto, found that the use of folic acid in the periconceptional period was 40%. Finding from Australia (Watson et al., 2006) showed that less than 50% of women took periconceptional folate supplementation and data from the National Birth Defects Prevention Study in the USA (Carmichael et al., 2006) reported that rate of folic acid supplement intake was 53% during the periconceptional period. A recent survey from South Korea (Kim et al., 2009) of 1277 women, found only 10.3% took folic acid periconceptionally.
to examine the rate of periconceptional and optimal folic acid supplementation, and to characterise their patterns and determinants among antenatal women in central China.
data from 4290 women in the Anhui Birth Defects and Child Development Cohort Study recruited between October 2008 and September 2009 were analysed.
seven Maternal and Child Health Centres of two cities (Hefei and Maanshan) in Anhui province of central China.
women initiating prenatal care were included and asked to complete a structured questionnaire regarding folic acid supplementation.
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.
optimal folic acid supplementation was relatively low.
further efforts are needed to inform the population and promote the use of folic acid supplementation.
Lack of periconceptional vitamins or supplements that contain folic acid and diabetes mellitusassociated birth defects
2012, American Journal of Obstetrics and Gynecology
Citation Excerpt :
If exact dates of use were unknown, mothers could report less specific information, such as a pregnancy month (eg, first month of pregnancy) or time of year (eg, beginning of the year), which was converted into dates to determine the timing of the use in relation to the pregnancy. NBDPS investigators determined whether the specific product that was reported contained folic acid.33 Periconceptional users of vitamins or supplements that contain folic acid were identified as mothers who reported any use during the month before conception or during the first 3 months of pregnancy.
The purpose of this study was to examine the risk of birth defects in relation to diabetes mellitus and the lack of use of periconceptional vitamins or supplements that contain folic acid.
The National Birth Defects Prevention Study (1997-2004) is a multicenter, population-based case-control study of birth defects (14,721 cases and 5437 control infants). Cases were categorized into 18 types of heart defects and 26 noncardiac birth defects. We estimated odds ratios for independent and joint effects of preexisting diabetes mellitus and a lack of periconceptional use of vitamins or supplements that contain folic acid.
The pattern of odds ratios suggested an increased risk of defects that are associated with diabetes mellitus in the absence vs the presence of the periconceptional use of vitamins or supplements that contain folic acid.
The lack of periconceptional use of vitamins or supplements that contain folic acid may be associated with an excess risk for birth defects due to diabetes mellitus.
Why Do Canadian Women Fail to Achieve Optimal Pre-Conceptional Folic Acid Supplementation? An Observational Study
2011, Journal of Obstetrics and Gynaecology Canada
To determine the factors that put Canadian women at risk for not supplementing with folic acid (FA) in the three months before conception, as recommended for the prevention of infant neural tube defects.
This study used data from the Canadian Maternity Experiences Survey. We used Poisson regression analysis with a robust variance to determine which factors were associated with women not supplementing with FA in the three months prior to pregnancy as compared with women who did supplement.
Of the 6421 women surveyed, 57.7% were supplementing with FA pre-conceptionally. The risk factors associated with a lack of FA supplementation pre-conceptionally were maternal age < 19 (prevalence ratio [PR] = 0.50; 95% CI 0.36 to 0.69) or 20 to 24 (PR = 0.75; 95% CI 0.67 to 0.84); education below high school level (PR = 0.73; 95% CI 0.61 to 0.87), at high school level (PR = 0.77; 95% CI 0.71 to 0.83), or at post-secondary level other than university (PR = 0.93; 95% CI 0.88 to 0.97); being at or below the low-income cut-off (PR = 0.74; 95% CI 0.67 to 0.81); smoking before pregnancy (PR = 0.79; 95% CI 0.73 to 0.86); being non-fluent in the language of the health care provider (PR = 0.66; 95% CI 0.49 to 0.88); being obese (BMI ≥ 30) (PR = 0.91; 95% CI 0.85 to 0.98); being unemployed (PR = 0.94; 95% CI 0.89 to 1.00); and being born outside of Canada (PR = 0.79; 95% CI 0.74 to 0.84).
Young maternal age, low education, low income, smoking, language barriers, obesity, unemployment, and being born outside Canada are risk factors for suboptimal or lack of FA supplementation pre-conceptionally.
Déterminer les facteurs qui exposent les Canadiennes au risque de ne pas prendre des suppléments d’acide folique (AF) au cours des trois mois précédant la conception, tel que recommandé pour la prévention des anomalies du tube neural chez l’enfant.
Cette étude a utilisé des données issues de l’Enquête canadienne sur l’expérience de la maternité. Nous avons utilisé une analyse de régression de Poisson et une robuste variance pour déterminer les facteurs qui étaient associés aux femmes ne prenant pas de suppléments d’AF au cours des trois mois précédant la grossesse, par comparaison avec les femmes qui prenaient de tels suppléments.
Chez les 6 421 femmes étudiées, 57,7 % prenaient des suppléments d’AF de façon préconceptionnelle. Parmi les facteurs de risque associés à l’absence d’une supplémentation à l’AF préconceptionnelle, on trouvait l’âge maternel < 19 ans (taux de prévalence [TP] = 0,50; IC à 95 %, 0,36 - 0,69) ou se situant entre 20 et 24 ans (TP = 0,75; IC à 95 %, 0,67 - 0,84); un niveau de scolarité se situant en deçà des études secondaires (TP = 0,73; IC à 95 %, 0,61 - 0,87), équivalant aux études secondaires (TP = 0,77; IC à 95 %, 0,71 - 0,83) ou équivalant à des études postsecondaires autres que les études universitaires (TP = 0,93; IC à 95 %, 0,88 - 0,97); le fait de se situer au seuil de faible revenu ou en deçà (TP = 0,74; IC à 95 %, 0,67 - 0,81); le tabagisme avant la grossesse (TP = 0,79; IC à 95 %, 0,73 - 0,86); le fait de ne pas être à l’aise dans la langue parlée par le fournisseur de soins (TP = 0,66; IC à 95 %, 0,49 - 0,88); l’obésité (IMC ≥ 30) (TP = 0,91; IC à 95 %, 0,85 - 0,98); le fait d’être sans emploi (TP = 0,94; IC à 95 %, 0,89 - 1,00); et le fait d’être née à l’étranger (TP = 0,79; IC à 95 %, 0,74 - 0,84).
Le jeune âge maternel, un faible niveau de scolarité, un faible revenu, le tabagisme, les obstacles de langue, l’obésité, le chômage et le fait d’être née à l’étranger constituent des facteurs de risque en ce qui concerne une supplémentation à l’AF préconceptionnelle sous-optimale ou même absente.
Epidemiological Factors in Developmental Toxicology
2010, Comprehensive Toxicology, Second Edition
Human experience is the ultimate test of risks for human congenital anomalies following exposures during pregnancy. The gold standard for human safety studies is the randomized clinical trial. However, due to ethical constraints, only in few instances is it possible to conduct such trials to evaluate the teratogenicity of a specific exposure. Various types of observational epidemiological studies provide the major source of information regarding human teratogenicity. There are numerous methodological challenges in conducting studies of prenatal exposures in relation to rare outcomes such as birth defects, and each of the commonly used study designs has limitations. Therefore, for many exposures in pregnancy, the available data are limited in quantity and quality. Multiple types of study designs are needed to appropriately evaluate exposures. A systematic program for collecting these data and a coordinated plan for interpretation is recommended.

View all citing articles on Scopus

: Supported by a cooperative agreement from the Centers for Disease Control and Prevention, Centers of Excellence (Award no. U50/CCU913241) and National Institutes of Health Grant R01 HD042538-01.

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General Obstetrics and Gynecology: ObstetricsCorrelates of intake of folic acid–containing supplements among pregnant women

Objective

Study design

Results

Conclusion

Section snippets

Material and methods

Results

Comment

Acknowledgment

Recommendations for the use of folic acid to reduce the number of cases of spina bifida and other neural tube defects

MMWR Morb Mortal Wkly Rep

Dietary reference intakes for thiamin, riboflavin, niacin, vitamin B6, folate, vitamin B12, pantothenic acid, biotin, and choline

Do multivitamin or folic acid supplements reduce the risk for congenital heart defects? Evidence and gaps

Am J Med Genet

Multivitamin supplementation and risk of birth defects

Am J Epidemiol

Risks of orofacial clefts in children born to women using multivitamins containing folic acid periconceptionally

Lancet

Maternal periconceptional use of multivitamins and reduced risk for conotruncal heart defects and limb deficiencies among offspring

Am J Med Genet

Maternal supplemental and dietary zinc intake and the occurrence of neural tube defects in California

Am J Epidemiol

Folic acid: nutritional biochemistry, molecular biology, and role in disease processes

Mol Genet Metab

Estimated folate intakes: data updated to reflect food fortification, increased bioavailability, and dietary supplement use

Am J Clin Nutr

Achieving a public health recommendation for preventing neural tube defects with folic acid

Am J Public Health

Preconceptional and prenatal multivitamin-mineral supplement use in the 1988 National Maternal and Infant Health Survey

Am J Public Health

Use of vitamins containing folic acid among women of childbearing age—United States, 2004

MMWR Morb Mortal Wkly Rep

Knowledge and use of folic acid by women of childbearing age—United States, 1995 and 1998

MMWR Morb Mortal Weekly Rep

Surveillance for selected maternal behaviors and experiences before, during, and after pregnancy. Pregnancy Risk Assessment Monitoring System (PRAMS), 2000

MMWR Surveill Summ

General Obstetrics and Gynecology: Obstetrics
Correlates of intake of folic acid–containing supplements among pregnant women