title: Sex ratio in the offspring of male radiologists.
abstract: OBJECTIVE
  The purpose of this study was to determine if male radiologists predominantly father daughters and, if so, to investigate the association between this skewed sex ratio of offspring and radiation exposure.
  
  
  METHODS
  Questionnaires completed by 586 male radiologists in Japan provided data regarding the radiologist's age, length of employment in radiology, if he had ever received radiation doses higher than that recommended by the International Commission on Radiological Protection, the sex of each child fathered, and the birth date of each child.
  
  
  RESULTS
  As a group, male radiologists tended to father a lower proportion of boys (48.47%) compared with the control group (51.46%), and the relative risk was 1.13 (95% confidence interval [CI]: 1.00, 1.27). Offspring of highly irradiated radiologists, however, had a reduced proportion of males (34.48%), with a significantly (P = .002) increased relative risk of 2.01 (95% CI: 1.29, 3.13).
  
  
  CONCLUSIONS
  X-ray exposure may explain the reduced percentage of sons in the offspring of male radiologists.
authors.affiliation: Department of Radiology, National Defense Medical College, Tokorozawa, Saitama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Hama
authors.forename: M
authors.initials: M
authors.lastname: Uematsu
authors.forename: Y
authors.initials: Y
authors.lastname: Sakurai
authors.forename: S
authors.initials: S
authors.lastname: Kusano
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D016273:Occupational Exposure; D018812:Paternal Exposure; D011827:Radiation; D011871:Radiology; D012744:Sex Ratio; D011795:Surveys and Questionnaires; D014965:X-Rays