Population-based case control study of folic acid supplementation during pregnancy

Teratology. 1996 Jun;53(6):345-51. doi: 10.1002/(SICI)1096-9926(199606)53:6<345::AID-TERA5>3.0.CO;2-Z.

Abstract

Previous studies have demonstrated that periconceptional folic acid/multivitamin supplementation reduced the occurrence of neural tube defects. A case control analysis has been conducted in the dataset of the Hungarian Case Control Surveillance of Congenital Abnormalities, 1980-1991. In the study period, 54.9% of 30,663 pregnant women who had healthy babies (negative control group) were supplemented with high doses (in general 2 x 3 mg) of folic acid per day. In those 17,300 pregnant women who had offspring with congenital abnormalities, the rate of folic acid supplementation was 50.4%. Exposure histories: preconceptional, I, II, III, and IV-IX postconceptional months were determined by record reviews and questionnaire assessment. The case control pair analysis showed a significant protection after folic acid supplementation during the critical period of cardiovascular defects, neural tube defects, cleft lip with or without cleft palate and posterior cleft palate.

MeSH terms

  • Case-Control Studies
  • Female
  • Folic Acid / administration & dosage*
  • Humans
  • Neural Tube Defects / chemically induced
  • Pregnancy

Substances

  • Folic Acid