Effects of microwave exposure in utero on embryonal, fetal and postnatal development of mice

Pregnant Swiss mice were repetitively exposed during various periods of gestation to 2,450 MHz continuous wave microwave radiation. Irradiations were conducted daily in an anechoic chamber at a power density of 10 (subthermal) or 40 mW/cm2 (thermal) for 2 h/day, 7 sessions/week. Thermal exposures to microwaves resulted in significant inhibition of the embryonal and fetal development in utero, accompanied by an increased incidence of intrafetal bleedings, resorptions and deaths of fetuses. Moreover, nonspecific resistance to viral and bacterial infections was markedly depressed in pups of dams irradiated for the whole period of gestation with thermal doses of microwaves. No such effects were found following exposure of pregnant mice to 10 mW/cm2 power density of radiation. The results suggest that the observed effects of microwave exposure in the course of pregnancy are thermal in nature.