Abstract. In our study, we examined white laboratory rats born from control and experimental mothers with hypothyroidism. As a result of morphological analysis of the pancreas in different periods of postnatal ontogenesis, significant changes in the delay in the development and formation of individual components of the vascular wall were revealed compared to the control group. From the first days after the start of the experiment, changes in the arterial wall were noted in all experimental animals. The results show that morphological changes in the cells of the pancreas and its blood vessels occur in the offspring born from mothers with hypothyroidism.