title: Folic acid supplementation in early second trimester and the risk of preeclampsia.
abstract: OBJECTIVE
  The objective of the study was to evaluate the association between folic acid supplementation in early second trimester and the risk of developing preeclampsia.
  
  
  METHODS
  We carried out a prospective cohort study between October 2002-December 2005. We recruited women who had their prenatal care visit (12-20 weeks' gestation) at the Ottawa Hospital and Kingston General Hospital. All charts for participants with a diagnosis of preeclampsia were audited and blindly adjudicated by 4 study investigators to validate the diagnosis.
  
  
  RESULTS
  A total of 2951 pregnant women were included in the final analysis. Supplementation of multivitamins containing folic acid was associated with increased serum folate (on average 10.51 micromol/L), decreased plasma homocysteine (on average 0.39 micromol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75).
  
  
  CONCLUSIONS
  Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.
authors.affiliation: OMNI Research Group, Department of Obstetrics and Gynecology, University of Ottawa, Faculty of Medicine, Ottawa, Ontario, Canada. swwen@ohri.ca
authors.forename: Shi Wu
authors.initials: SW
authors.lastname: Wen
authors.forename: Xi-Kuan
authors.initials: XK
authors.lastname: Chen
authors.forename: Marc
authors.initials: M
authors.lastname: Rodger
authors.forename: Ruth Rennicks
authors.initials: RR
authors.lastname: White
authors.forename: Qiuying
authors.initials: Q
authors.lastname: Yang
authors.forename: Graeme N
authors.initials: GN
authors.lastname: Smith
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Sigal
authors.forename: Sherry L
authors.initials: SL
authors.lastname: Perkins
authors.forename: Mark C
authors.initials: MC
authors.lastname: Walker
mesh_terms: D000328:Adult; D015331:Cohort Studies; D016001:Confidence Intervals; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage*; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000453:epidemiology* / Q000517:prevention & control; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011295:Prenatal Care / Q000379:methods; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment
chemical_list: D005492:Folic Acid