Answer to Question #2070 Submitted to "Ask the Experts"

Q

I had a CT scan of my abdomen and pelvic area six weeks ago. My doctor told me to wait one menstrual cycle before trying to conceive. Is there any evidence that suggests waiting longer or is it okay to conceive at this time?

A

The dose of ionizing radiation you receive to your ovaries from a CT scan of the abdomen is very low and the risk of producing a genetic change in the ovary that may be manifested in your future pregnancies is also very low. In fact, the scientists who studied the survivors of the atomic bomb in Japan did not demonstrate any increased genetic or reproductive effects in the next generation. Be that as it may, because experimentally we know that the ova ovulated in the first few cycles after an exposure to radiation have a higher risk of a genetic effect, we recommend that women who have received radiation therapy wait for three cycles before they attempt to get pregnant. For someone who had a CT scan, like yourself, your exposure is far less them some who is receiving radiation therapy to the abdomen. But since waiting three months is usually not a hardship, we advise that to women as well. If you happen to get pregnant before the three months, the risks are so low that no one should suggest that such a pregnancy was at risk. In the meantime you should realize that the risks that are present in every pregnancy are 3% for birth defects and 15% for miscarriage. This is for healthy women without reproductive or genetic problems in themselves or their family history. I wish you well. Robert L. Brent, MD, PhD