Answer to Question #8772 Submitted to "Ask the Experts"

Category: Pregnancy and Radiation — Flying

The following question was answered by an expert in the appropriate field:


My husband is planning a round-trip from Germany to California, United States, and also plans to take some cross-country flights in the United States. In total he will spend 40 hours on a plane during 14 days. Is it safe to try to conceive right after that, or should I postpone it due to the risk of cancer for our future baby?


The exposure that your husband will receive from flying is extremely low. The reproductive and genetic risks of radiation to your husband's sperm has been extensively studied. Actually, in your case the risks are very small. First of all, the exposure is very low. Preconception radiation risks have been studied in large populations of women and men who have been treated for cancer with chemotherapeutic drugs and radiation and have mothered or fathered a child. Similarly, the atomic bomb survivors have been studied, and numerous survivors who had exposures that were 100 times greater than he would receive had no measurable increase in genetic disease, birth defects, or cancer in their offspring. Both these populations have been extensively studied and in neither population is there an increase in reproductive or developmental risks, although theoretically one would expect an increased risk of genetic abnormalities.

Very high exposures can cause pregnancy loss (miscarriage) or infertility. His exposures are far too low to be concerned about those risks. Based on the genetic developmental risks, we advise women who have had their ovaries exposed to high doses of radiation to wait for three menstrual cycles before attempting to become pregnant. Men who have been exposed should wait at least two spermatogenesis cycles. That is about four months. In your husband's case, the exposure is so low that it really does not matter when you attempt to get pregnant. I wish you well in your future pregnancies.

Remember that every man and woman with a normal personal and genetic family reproductive history has the background reproductive developmental risks that are 3% for birth defects, 11% for genetic diseases, and 15% for miscarriage. We cannot change those risks, as yet.

Robert Brent, MD, PhD

Ask the Experts is posting answers using only SI (the International System of Units) in accordance with international practice. To convert these to traditional units we have prepared a conversion table. You can also view a diagram to help put the radiation information presented in this question and answer in perspective. Explanations of radiation terms can be found here.
Answer posted on 5 January 2010. The information posted on this web page is intended as general reference information only. Specific facts and circumstances may affect the applicability of concepts, materials, and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice. To the best of our knowledge, answers are correct at the time they are posted. Be advised that over time, requirements could change, new data could be made available, and Internet links could change, affecting the correctness of the answers. Answers are the professional opinions of the expert responding to each question; they do not necessarily represent the position of the Health Physics Society.