The dexamethasone, a synthetic glucocorticoid, has the ability to cross the placenta by increasing the level of movement of corticosteroids from mother to fetus during pregnancy. When administered in the late stages of pregnancy can produce effects undesirable on placental formation. The present study aimed to investigate the effect of administration of dexamethasone (0.8mg/day/animal) in the first five days of pregnancy, on placental development in rats. We used 30 albino rats, divided into two groups: Group I -pregnant rats without the application of dexamethasone, sacrificed to the 7th and 14th day. Group II -rats subjected to the application of dexamethasone in the first five days of pregnancy, sacrificed to the 7th and 14th day. The results showed that dexamethasone did not affect the number and histology of the implantation sites, but promoted changes in the disk placental causing hypertrophy in trophoblastic giant cell layer. No changes were found in the content of collagen, but there was interference with the metabolism of glycogen in spongiotrophoblast. The morphometry of lines showed, a difference between groups in the region of labyrinth and trophoblast giant cell. However, in morphometry of points there was a difference between groups in the region of labyrinth.
Dexamethasone; placenta; histochemical morphometry; rat
