Foetal Dosimetry

ct gravid abdomen

This patient was involved in a motor vehicle accident, while 35 weeks pregnant.

Although exposure to the gravid uterus is to be avoided when ever possible, and only deliberately performed after careful weighing up of the pros and cons, McCollough et al conclude their recent Radiographics article with: “After comparing the doses from radiologic and nuclear medicine examinations with risk data from human in utero exposures, we have concluded that the absolute risks of fetal effects, including childhood cancer induction, are small at conceptus doses of 100 mGy and negligible at doses of less than 50mGy.” (1)

Doses from diagnostic procedures are all below these thresholds – even a CT abdomen / pelvis only delivers approximately 30 mGy.

For the doses of other common investigations please visit here.


1. McCollough et al. “Radiation Exposure and Pregnancy: When Should We Be Concerned?” RadioGraphics 2007; 27:909–918

Credit: Dr Frank Gaillard