Herbs and spices are frequently used for culinary and medicinal intention. One of the herbs that is extremely consumed in dietary and therapeutic object is garlic (Allium sativum) with special concern in urban countries. Nevertheless, various controversies persist about the advantageous or the toxic effects of garlic depending on administration mode and garlic dosage. Twenty female pregnant rats were evenly distributed into two groups, control and treated groups (n = 10). In the treated group, each pregnant rat received orally 2 g/kg body weight of aqueous garlic extract on day 6 of pregnancy. On the 20^th day of gestation, morphological, biochemical, and histological investigations were performed to appreciate the cellular abnormalities in the maternal ovary and damage in liver and spleen of both pregnant rats and their embryos. The results showed that garlic extract at a dose of 2 g/kg body weight produced an intense cytotoxic effect on the liver and splenic tissues of the pregnant females and their progeny and obviously-detected congenital malformations in the progression of the fetuses. A significant elevation in the aspartate aminotransferase activity and the levels of the total proteins, interleukin-6, malondialdehyde, and nitric oxide; while a significant reduction in the activities of superoxide dismutase and glutathione peroxidase were detected in the garlic-treated group when compared with the control group. In conclusion, garlic disrupts significantly the liver functions and immunity of the pregnant rats. Moreover, congenital deformations were detected in the fetuses of the garlic-treated pregnant rats.