Rationale and Objectives. The purpose of this study was to determine if mal
e radiologists predominantly father daughters and, if so, to investigate th
e association between this skewed sex ratio of offspring and radiation expo
Materials and 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 reco
mmended 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 hig
hly 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).
Conclusion. X-ray exposure may explain the reduced percentage of sons in th
e offspring of male radiologists.