Pregnancy and radiation.

The risk of foetal irradiation during pregnancy is discussed. It seems that, due to the low level of X-ray exposure to the foetus, neither diagnostic radiography nor nuclear diagnostic examination justifies termination of pregnancy. Radiotherapy for breast cancer, Hodgkin's disease and cervical cancer in pregnant women is reviewed. Radiation therapy for breast cancer is not an absolute contraindication for pregnancy and the risk-benefit assessment should be discussed with the mother. The risk to the foetus during radiotherapy for supradiaphragmatic Hodgkin's disease appears to be minimal, provided special attention is paid to the treatment techniques and the foetus is adequately shielded. Radiotherapy for the treatment of cervical cancer may be necessary during pregnancy, but the timing should be adjusted taking into consideration gestational age. Offspring of cancer patients who were treated by radiotherapy appear to be at little risk of childhood cancer or birth defects. Cancer patients should not be discouraged from having children and can expect a good outcome of pregnancy. However, in the non-pregnant woman, to further reduce any risk it is advisable to delay pregnancy for 12 months following completion of radiation therapy.