Reaction of posterity of two generations after exposure of pregnant Wistar rats to low dose irradiation during the period of fetus formation. Development of the first generation posterity

Whole-body single exposure of female Wistar rats to 0.25, 0.5 and 1 Gy of gamma-rays (dose rate of 0.03 cGy/s) on the 10th day of pregnancy (a period of formation of the reproductive system in fetus) was carried out. To study irradiation consequences on the antenatal and postnatal development of the progeny 220 females, 700 19-day-old fetuses and about 1100 young rats were examined. The antenatal development of the progeny of the first generation was significantly impaired after the exposure to 1 Gy. However even less radiation doses resulted in a pronounced tendency to higher rates of intrauterine death and a lower number of live fetuses. Significant deviatins in the postnatal development of the first generation progeny were found after the exposure to 0.5 Gy, although the exposure to 0.25 Gy led to a higher rate of postnatal death and a less number of newborns in the litter.