Chronic exposure of livestock to Ipomoea carnea, a toxic plant, promotes toxicosis characterized by lysosomal vacuolization of different organs, and is clinically manifested by CNS signs, abnormal endocrine and gastrointestinal functions, alteration of the immune system, and abnormal embryogenesis. The present study evaluated the effects of different doses of the plant extract on pregnant rats and their offspring after oral administration to the dams from day 6 to day 20 of gestation. Histopathology of thyroid, pancreas, liver and kidneys of dams on gestational day 21 showed characteristic vacuolization promoted by I. carnea toxicosis in these organs; the same was observed in the organs of 7-d-old pups. On the other hand, no alteration was found in these same organs of dams the 7th d after parturition. Although the lesions were reversed in the dams, the same did not occur in their pups. I. carnea administration also promoted decreased body weight, thymus atrophy and spleen enlargement in pups. The toxic principle of I. carnea (swainsonine) seems to pass through the placenta.