Birth defects and fertility after radiation for testicular cancer

Last Modified: September 26, 2004

Dear OncoLink "Ask The Experts,"
I was diagnosed with stage I seminoma in December 2002 and had my left testicle removed shortly after. In March 2004, I was told I had to get radiation treatments because the cancer reappeared in the para-aortic lymph nodes. I received 27 treatments covering an area beneath the sternum to the pelvis.

This week, my wife, who was close to nine months (37 weeks) pregnant, lost the baby she was carrying for no apparent reason and we are devastated by this news. We are talking of trying again for another baby.

My oncologist suggested we should wait for at least a year before conceiving again. I read somewhere that there should be no reason for us to wait that long since the effects of the radiation on the other testicle are "gone". How long should I wait before trying to conceive again?

Richard Whittington, MD, Associate Professor of Radiation Oncology at the University of Pennsylvania School of Medicine, responds:

The reason that one year is recommended is based on what was called the "mega mouse experiment." Researchers exposed millions of mice to radiation so they could determine the risk of birth defects. It seems that there is no standard birth defect that one can attribute to radiation, but rather that all birth defects occur more commonly. In the general population, about 3% of all infants have some sort of birth defect and most are very minor. The risk of birth defects after radiation is slightly increased for a period of 8 to 9 months. However, the risk is generally less than 10%, and probably less than 5%. It is for this reason that most radiation oncologists recommend a year to be safe. It took literally millions of mice to find this risk and quantitate it. A small series of people from the military hospitals looked at infants conceived in the first year and there were only about 80 pregnancies and found no increased risk. It must be remembered that although the risk is low, having a child with birth defects can bring on enormous unexpected responsibilities and feelings of guilt.