Answer to Question #2243 Submitted to "Ask the Experts"

Q

Is it possible for radiation from a hysterosalpinogram to cause ova to be aneuploid both while the ova are contained in the ovaries as well as when the ova are fertilized?

A

Effects on unfertilized ova are in the class of genetic effects of radiation, while those on fertilized ova are effects on the embryo.

Genetic effects of radiation are those expressed in future generations. They are extremely rare events. They have been documented following large doses in experimental animals, ranging from fruit flies to rodents, but not in humans—even in the offspring of Japanese atomic bomb survivors. There is currently debate among scientists as to whether small doses of radiation, such as from diagnostic x ray (including hysterosalpingogram), can produce any genetic effects at all. The World Health Organization estimates that about 11% of babies born worldwide carry some genetic defect, ranging from trivial (such as an inconspicuous birthmark) to severe. Genetic effects of radiation mimic nature; they are indistinguishable from those arising spontaneously. Detection of a very rare event, say one in a billion, from radiation would be very difficult. Effects on the embryo fall in a different category, called deterministic effects. Every individual who gets sufficient dose gets the effect. Severity of the effect is proportional to dose. There are threshold doses below which severity of the effect is trivial. Threshold doses for effects on the embryo are much larger (factors of 10-100) than doses delivered in hysterosalpingography. Further, the only effect documented before implantation (within 10 to 14 days of conception) at any dose is early death of the embryo, resulting in an early unrecognizable abortion.

Conclusion: It is extremely unlikely and possibly impossible that hysterosalpingography could have any effect on unfertilized ova. It is for all practical purposes impossible to have any effect on recently fertilized ova.

S.Julian Gibbs, DDS, PhD