Anesthesia as an effective agent against the production of congenital anomalies in mouse fetuses exposed to electromagnetic radiation.

A total of 130 female mice pregnant at 8 days were exposed singly to a 7.3 watt microwave waveguide at 2,450 MHz wave length while being monitored for total obsorbed dose, the exposure being four minutes. Among the 1,328 offspirng examined (327 of which were controls) those not anesthetized but irradiated showed greater fetal damage than those that were anesthetized and placed in one of the three positions with respect to the radiation beam. Immobilization with anesthesia and restraint in the broadside position provided the greatest protection to the fetus against any teratologic effects. Anesthesia reduces the body temperature to a degree equivalent to the rise in temperature expected from the radiation conditions used, hence the protection against the primary thermal effect of microwave irradiation.