Objectives: Compare the histological structure of a liver and a spleen of the experimental groups in relation to the control group. Compare the number of mast cells and the number of mitochondria in the liver and compare the amount of connective tissue and the ratio of red and white pulp in the following experimental groups versus the control group. Study Design: This study was designed as a case-control study. The study included three groups of animals whose mothers, Sprague Dawley rats, had been treated with the antihistamines desloratadine or bilastine since the 10th gestational day of pregnancy or had not been treated. The groups were further divided into male and female offspring. Materials and methods: Prepared liver tissue for analysis was stained with hemalaun and eosin to show histological structure, Toluidine blue to show mast cells and PTAH staining to show the amount of liver mitochondria. Hemalaun and eosin were used to visualize the spleen tissue, which was used to show the ratio of red and white pulp and picrosirius staining, which was used to show the amount of connective tissue. Results: There is a statistically significant difference in the amount of double nuclei in hepatocytes in male Sprague Dawley rats’ offspring treated with desloratadine while, in the female group of rats’ offspring, no statistically significant difference is revealed. The numbers of mitochondria and mast cells in the liver were not altered in the rats’ offspring untreated and treated with the antihistamines desloratadine and bilastine. The ratio of red and white pulp of rats’ offspring untreated and treated with antihistamines, as well as the percentage of reticulin fibers in the visual field, remains unchanged. Conclusion: The use of antihistamines desloratadine and bilastine does not cause changes in the development of the liver and spleen of the offspring of pregnant Sprague Dawley rats. There is no increase in the number of mast cells in the liver and the ratio of red and white pulp does not change in the spleen.