Effect of "in Utero" Exposure to Low Doses of Low Energy X-rays on the Postnatal Development of Mouse

Pregnant Swiss albino mice were exposed to a single dose of 9 mGy or 50 mGy of 70 kVp X-rays on day 3.5 (preimplantation), 6.5 (early organogenesis) or 11.5 (late organogenesis) of gestation. The offspring were observed for any radiation induced changes in litter size at birth and sex ratio at 4 wks of age, and postnatal mortality and growth retardation up to 6 wks of age. Irradiation at the early organogenesis stage produced an increase in the postnatal death, statistically significant in the 50 mGy group. A significant increase in the number of retarded offspring and decrease in body weight were observed in the groups exposed at the early and late organogenesis periods. The results indicate that a single exposure to low energy low dose X-rays can be harmful to the growing embryos and the type and extent of the injury will depend on the stage of development as well as the dose of radiation.