Jun 15, 1996

Case-control study of periconceptional folic acid supplementation and oral clefts

American Journal of Epidemiology
C HayesA A Mitchell


There is consistent evidence that the risk of neural tube defects is decreased by periconceptional supplementation with folic acid. A similar protective effect has been postulated for oral clefts. A case-control study was conducted in greater metropolitan Boston; Massachusetts; Philadelphia, Pennsylvania; and southeastern Ontario, Canada, from 1988 through 1991 to test the hypothesis that folic acid supplementation during the periconceptional period reduces the risk of oral clefts. Crude and multivariate-adjusted relative risks were calculated for all oral clefts (n = 303), cleft palate (n = 108), and cleft lip with or without cleft palate (n = 195). Controls (n = 1,167) were liveborn or stillborn infants less than age 6 months who had various congenital anomalies other than oral clefts, neural tube defects, or other "midline defects." Adjusted relative risks and 95 percent confidence intervals for daily folic acid supplementation during the periconceptional period were: oral clefts, 1.1 (95% confidence interval (CI) 0.8-1.7), cleft palate, 0.9 (95% CI 0.5-1.6), and cleft lip with or without cleft palate, 1.3 (95% CI 0.8-2.1). These findings do not support a protective association between the periconceptional use of folic acid ...Continue Reading

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Mentioned in this Paper

Confidence Intervals
Neural Tube
Congenital Neurologic Anomalies
Cleft Palate, Isolated
Folic acid supplementation
Midline Cell Component
Cleft Lip With or Without Cleft Palate
Multivariate Analysis

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