title: Occurrence of omphalocele in relation to maternal multivitamin use: a population-based study.
abstract: OBJECTIVE
  We evaluated the association between mothers' use of multivitamin supplements and their infants' risk for omphalocele, a congenital anomaly of the abdominal wall. Omphalocele can occur in certain multiple congenital anomaly patterns with neural tube defects, for which a protective effect of multivitamins with folic acid has been demonstrated.
  
  
  METHODS
  We used data from a population-based case-control study of infants born from 1968-1980 to mothers residing in metropolitan Atlanta. Case-infants with nonsyndromic omphalocele (n = 72) were actively ascertained from multiple sources. Control-infants (n = 3029), without birth defects, were selected from birth certificates by stratified random sampling.
  
  
  RESULTS
  Compared with no use in the periconceptional period, periconceptional use of multivitamin supplements (regular use from 3 months before pregnancy through the first trimester of pregnancy) was associated with an odds ratio for nonsyndromic omphalocele of 0.4 (95% confidence interval [CI]: 0.2-1.0). For the subset comprising omphalocele alone or with selected midline defects (neural tube defects, hypospadias, and bladder/cloacal exstrophy), the odds ratio was 0.3 (95% CI: 0.1-0.9). These estimates were similar when the reference group also included women who began using multivitamins late in pregnancy (during the second or third month of pregnancy). The small number of participants limited the precision of subgroup analyses and translated into wide confidence intervals that included unity.
  
  
  CONCLUSIONS
  Periconceptional multivitamin use was associated with a 60% reduction in the risk for nonsyndromic omphalocele. These findings await replication from additional studies to confirm the findings, generate more precise estimates, and detail possible mechanisms of actions.
authors: National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. lbotto@cdc.gov
authors: Lorenzo D
authors: LD
authors: Botto
authors: Joseph
authors: J
authors: Mulinare
authors: J David
authors: JD
authors: Erickson
mesh_terms: D016022:Case-Control Studies; D016001:Confidence Intervals; D000013:Congenital Abnormalities / Q000453:epidemiology; D019587:Dietary Supplements; D005260:Female; D006554:Hernia, Umbilical / Q000453:epidemiology* / Q000517:prevention & control*; D006801:Humans; D007231:Infant, Newborn; D016017:Odds Ratio; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011295:Prenatal Care; D015995:Prevalence; D018570:Risk Assessment; D016896:Treatment Outcome; D014815:Vitamins / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D014815:Vitamins