title: Maternal exposure to radiographic exams and major structural birth defects.
abstract: BACKGROUND
  An increasing number of radiologic exams are performed in the United States, but very few studies have examined the effects of maternal exposure to radiologic exams during the periconceptional period and birth defects.
  
  
  OBJECTIVE
  To assess the association between maternal exposure to radiologic exams during the periconceptional period and 19 categories of birth defects using a large population-based study of birth defects.
  
  
  METHODS
  We studied 27,809 case mothers and 10,200 control mothers who participated in the National Birth Defects Prevention Study and delivered between 1997 and 2009. Maternal exposure to radiologic exams that delivered ionizing radiation to the urinary tract, lumbar spine, abdomen, or pelvis were identified based on the mother's report of type of radiologic exams, organ or body part scanned and the month during which the exam occurred
  
  
  RESULTS
  Overall, 0.9% of mothers reported exposure to one of these types of radiographic exams during the periconceptional period. We observed significant associations between maternal exposure during the first trimester and isolated Dandy-Walker malformation (odds ratio = 7.7; 95% confidence interval, 1.8-33) and isolated d-transposition of the great arteries (odds ratio = 3.8; 95% confidence interval, 1.4-10.3). However, the result for isolated Dandy-Walker malformation was based on only two exposed cases.
  
  
  CONCLUSIONS
  These results should be interpreted cautiously because multiple statistical tests were conducted and measurements of exposure were based on maternal report. However, our results may be useful for generating hypotheses for future studies. Birth Defects Research (Part A) 106:563-572, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: University of Texas School of Public Health, Houston, Texas.
authors.forename: Hyeyeun
authors.initials: H
authors.lastname: Lim
authors.affiliation: University of Texas School of Medicine, Houston, Texas.
authors.forename: Charles W
authors.initials: CW
authors.lastname: Beasley
authors.affiliation: University of Texas School of Public Health, Houston, Texas.
authors.forename: Lawrence W
authors.initials: LW
authors.lastname: Whitehead
authors.affiliation: University of Texas School of Public Health, Houston, Texas.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Emery
authors.affiliation: University of Texas School of Public Health, Houston, Texas.
authors.forename: A J
authors.initials: AJ
authors.lastname: Agopian
authors.affiliation: Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, Texas.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Langlois
authors.affiliation: University of Texas School of Public Health, Houston, Texas.
authors.forename: Dorothy K
authors.initials: DK
authors.lastname: Waller
mesh_terms: D000016:Abnormalities, Radiation-Induced / Q000453:epidemiology*; D000328:Adult; D005260:Female; D006801:Humans; D018811:Maternal Exposure / Q000009:adverse effects*; D011247:Pregnancy; D011860:Radiography, Abdominal / Q000009:adverse effects*; D012189:Retrospective Studies
keywords: birth defects; isolated d-transposition of the great arteries; radiography