Folic acid supplementation in early second trimester and the risk of preeclampsia
Received 20 November 2006; received in revised form 17 April 2007; accepted 29 June 2007.
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.
Study Design
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 μmol/L), decreased plasma homocysteine (on average 0.39 μmol/L), and reduced risk of preeclampsia (adjusted odds ratio, 0.37; 95% confidence interval, 0.18-0.75).
Conclusion
Supplementation of multivitamins containing folic acid in the second trimester is associated with reduced risk of preeclampsia.
aOMNI Research Group, Department of Obstetrics and Gynecology, University of Ottawa, Faculty of Medicine, Ottawa, Ontario, Canada
bDepartment of Epidemiology and Community Medicine, University of Ottawa, Faculty of Medicine, Ottawa, Ontario, Canada
cClinical Epidemiology Program, Ottawa Health Research Institute, Ottawa, Ontario, Canada
dDivision of Hematology, Department of Medicine, Queen’s University School of Medicine, Kingston, ON
eDepartment of Medicine, Queen’s University School of Medicine, Kingston, ON
fDivision of Biochemistry, Queen’s University School of Medicine, Kingston, ON
gQueen’s Perinatal Research Unit, Kingston General Hospital, and the Department of Obstetrics and Gynecology, Queen’s University School of Medicine, Kingston, ON
hDivision of Endocrinology, University of Calgary, Calgary, AB, Canada.
Reprints: Shi Wu Wen, MB, PhD, OMNI Research Group, Department of Obstetrics and Gynecology, University of Ottawa, Faculty of Medicine, 501 Smyth Rd, Box 241, Ottawa, Ontario, Canada K1H 8L6
Cite this article as: Wen SW, Chen X-K, Rodger M, et al. Folic acid supplementation in early second trimester and the risk of preeclampsia. Am J Obstet Gynecol 2008;198:45.e1-45.e7.
Supported in part by a grant from the Canadian Institute for Health Research (Grant MOP 53188). S.W.W., G.N.S., R.J.S., and M.C.W. are recipients of a New Investigators’ Award from the Canadian Institute for Health Research. M.R. is a Clinical Investigator of the Heart and Stroke Foundation of Canada, and X.-K.C. and Q.Y. are Canadian Institute for Health Research/Strategic Training Initiatives of Research in Reproductive Health Sciences postdoctor fellows.
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