Table 2.

Prenatal exposure to medical diagnostic radiation and risk estimates of childhood and adolescent brain tumors

CasesControlsCrude ORa (95% CI)Adjusted ORb (95% CI)
Ultrasound examination during mother's pregnancy
 Yes3355921 (ref)1 (ref)
 No14340.71 (0.36–1.38)0.64 (0.32–1.30)
 Missing320
No. of times
 No ultrasound14340.76 (0.38–1.50)0.71 (0.34–1.45)
 11142121 (ref)1 (ref)
 2961391.36 (0.95–1.94)1.46 (1.01–2.11)
 344940.95 (0.60–1.48)0.96 (0.61–1.53)
 4 or more771441.05 (0.70–1.58)1.11 (0.73–1.68)
 Missing43
Gestational week of the first ultrasound
 No ultrasound14340.91 (0.45–1.85)0.76 (0.36–1.64)
 1–121092061.13 (0.78–1.64)1.18 (0.81–1.73)
 13–241512881 (ref)1 (ref)
 25+13191.47 (0.63–3.40)1.79 (0.74–4.31)
 Missing6279
Maternal X-ray or other scan during pregnancy
 Yes31570.91 (0.54–1.55)0.96 (0.54–1.68)
 No3065561 (ref)1 (ref)
 Missing1533
No. of times
 No X-ray or scan3065561 (ref)1 (ref)
 130511.00 (0.58–1.72)1.00 (0.56–1.79)
 2 or more160.33 (0.04–2.77)0.43 (0.05–3.98)
 Missing
X-ray or scan to the abdomen
 Yes570.88 (0.25–3.04)0.72 (0.17–2.97)
 No X-ray or scan to the abdomen3326061 (ref)1 (ref)
  • aConditional logistic regression model.

  • bConditional logistic regression model adjusted for highest parental education, maternal age, and paternal age.