Nanoparticles because of their unique properties have widespread application in biomedicine and many industrial sectors. The present study was undertaken to determine the potential effects of AgNPs of different size on pregnant dams and fetal development after maternal exposure on gestational days (GD) 6-19 in mice. AgNPs, of 20nm and 1300 nm respectively were administered to pregnant mice by oral gavages at concentrations of 0.5 mg/kg/day and 1 mg/kg/day. All dams were subjected to Cesarean section on GD 20. The fetuses were evaluated for signs of embryotoxic and teratogenic effects. AgNPs caused a decrease in Catalase and Reduced Glutathione activities at ≥ 0. 5 mg/kg/day and a reduction in glutathione content at 1 mg/kg/day in maternal liver tissues. However, no treatment-related deaths or clinical signs were observed in any of the animals treated with AgNPs. Fetal liver tissue showed significant decrease in Catalase and Reduced Glutathione activities. Histomorphological alterations in the fetal liver were observed at 1300nm particle group which were exacerbated in 20 nm group. The results show that a repeated oral dose of AgNPs during pregnancy caused oxidative stress in fetal hepatic tissue which is not only dose dependent but also depends on the particle size.