Functional alterations in the hypothalamic-pituitary-thyroid axis in rats exposed prenatally to diazepam

Prenatal exposure to diazepam in the rat from day 15 to day 21 of gestation induced a decrease in serum thyroxine levels in both male and female animals at 3 and 6 weeks of age. Furthermore, female rats exposed prenatally to diazepam showed an increase in the TSH response to synthetic thyrotropin-releasing hormone (TRH) when tested at 10-12 weeks of age, though their serum thyroxine level was normal. The results suggest that prenatal exposure to diazepam in rats during the last week of gestation affects the functional development of hypothalamic-pituitary-thyroid axis.