Periconceptional Intake of Folic Acid and Food Folate and Risks of Preterm Delivery

ABSTRACT

We investigated multiple sources of folate and folic acid to determine whether their periconceptional intakes were associated with preterm delivery. Studied were controls from the National Birth Defects Prevention Study delivered September 1998 to December 2005. Telephone interviews were conducted with 5952 (68% of eligible) mothers. Women were queried about intake of vitamin supplements in the 12 weeks before conception through delivery. A version of the Nurse's Health Study food frequency questionnaire was used to assess food sources. Eight percent of infants (n = 487) were preterm (<37 weeks). Compared with women who began intake of supplements with folic acid before pregnancy, those who began any time during pregnancy had an ~20% lowered risk of preterm delivery. Lower dietary intakes showed a modest increased risk of preterm delivery: odds ratios were 1.44 (1.01 to 2.04) for lowest quartile intake of folate and 1.27 (0.95 to 1.69) for lowest quartile intake of folic acid compared with the highest. Findings suggest some evidence that folates influenced risks; however, an interpretation of results was also consistent with no association between intake of folates and preterm delivery.

KEYWORDS

Folic acid - preterm delivery - food folate - preconceptional intake - birth defects - preterm

REFERENCES

• 1 MRC Vitamin Study Research Group . Prevention of neural tube defects: results of the Medical Research Council Vitamin Study.  Lancet. 1991;  338 131-137
• 2 Blom H J, Shaw G M, den Heijer M, Finnell R H. Neural tube defects and folate: case far from closed.  Nat Rev Neurosci. 2006;  7 724-731
• 3 Scholl T O, Hediger M L, Schall J I, Khoo C S, Fischer R L. Dietary and serum folate: their influence on the outcome of pregnancy.  Am J Clin Nutr. 1996;  63 520-525
• 4 Shaw G M, Liberman R F, Todoroff K, Wasserman C R. Low birth weight, preterm delivery, and periconceptional vitamin use.  J Pediatr. 1997;  130 1013-1014
• 5 Scholl T O, Hediger M L, Bendich A, Schall J I, Smith W K, Krueger P M. Use of multivitamin/mineral prenatal supplements: influence on the outcome of pregnancy.  Am J Epidemiol. 1997;  146 134-141
• 6 Catov J M, Bodnar L M, Ness R B et al.. Association of periconceptional multivitamin use and risk of preterm or small-for-gestational-age births.  Am J Epidemiol. 2007;  166 296-303
• 7 Bukowski R, Malone F D, Porter F T et al.. Preconceptional folate supplementation and the risk of spontaneous preterm birth: a cohort study.  PLoS Med. 2009;  6 e1000061
• 8 Vahratian A, Siega-Riz A M, Savitz D A, Thorp Jr J M. Multivitamin use and the risk of preterm birth.  Am J Epidemiol. 2004;  160 886-892
• 9 Baumslag N, Edelstein T, Metz J. Reduction of incidence of prematurity by folic acid supplementation in pregnancy.  BMJ. 1970;  1 16-17
• 10 Rolschau J, Kristoffersen K, Ulrich M, Grinsted P, Schaumburg E, Foged N. The influence of folic acid supplement on the outcome of pregnancies in the county of Funen in Denmark. Part I.  Eur J Obstet Gynecol Reprod Biol. 1999;  87 105-110 discussion 103-104
• 11 Giles P FH, Harcourt A G, Whiteside M G. The effect of prescribing folic acid during pregnancy on birth-weight and duration of pregnancy. A double-blind trial.  Med J Aust. 1971;  2 17-21
• 12 Charles D HM, Ness A R, Campbell D, Smith G D, Whitley E, Hall M H. Folic acid supplements in pregnancy and birth outcome: re-analysis of a large randomised controlled trial and update of Cochrane review.  Paediatr Perinat Epidemiol. 2005;  19 112-124
• 13 Mathews F, Yudkin P, Neil A. Influence of maternal nutrition on outcome of pregnancy: prospective cohort study.  BMJ. 1999;  319 339-343
• 14 Hininger I, Favier M, Arnaud J et al.. Effects of a combined micronutrient supplementation on maternal biological status and newborn anthropometrics measurements: a randomized double-blind, placebo-controlled trial in apparently healthy pregnant women.  Eur J Clin Nutr. 2004;  58 52-59
• 15 Siega-Riz A M, Savitz D A, Zeisel S H, Thorp J M, Herring A. Second trimester folate status and preterm birth.  Am J Obstet Gynecol. 2004;  191 1851-1857
• 16 Shaw G M, Carmichael S L, Nelson V, Selvin S, Schaffer D M. Occurrence of low birthweight and preterm delivery among California infants before and after compulsory food fortification with folic acid.  Public Health Rep. 2004;  119 170-173
• 17 Shaw G M, Savitz D A, Nelson V, Thorp Jr J M. Role of structural birth defects in preterm delivery.  Paediatr Perinat Epidemiol. 2001;  15 106-109
• 18 Yoon P W, Rasmussen S A, Lynberg M C et al.. The National Birth Defects Prevention Study.  Public Health Rep. 2001;  116 (Suppl 1) 32-40
• 19 Willett W C, Reynolds R D, Cottrell-Hoehner S, Sampson L, Browne M L. Validation of a semi-quantitative food frequency questionnaire: comparison with a 1-year diet record.  J Am Diet Assoc. 1987;  87 43-47
• 20 US Department of Agriculture .Agricultural Research Service. USDA National Nutrient Database for Standard Reference 21 2009. Available at: http://www.nal.usda.gov/fnic/foodcomp Accessed August 2009
• 21 Cogswell M E, Bitsko R H, Anderka M National Birth Defects Prevention Study et al. Control selection and participation in an ongoing, population-based, case-control study of birth defects: the National Birth Defects Prevention Study.  Am J Epidemiol. 2009;  170 975-985
• 22 Block G. A review of validations of dietary assessment methods.  Am J Epidemiol. 1982;  115 492-505
• 23 Willett W C, Reynolds R D, Cottrell-Hoehner S, Sampson L, Browne M L. Validation of a semi-quantitative food frequency questionnaire: comparison with a 1-year diet record.  J Am Diet Assoc. 1987;  87 43-47
• 24 Willett W. Nutritional Epidemiology. 2nd ed. Oxford: Oxford University Press; 1998