Maternal treatment with dexamethasone at minimal therapeutic doses inhibits neonatal bone development in a gender-dependent manner

The structural quality of bone is genetically determined, and remains under the influence of hormonal modification. A gender-dependent effect of prenatal treatment with multiple therapeutic minimal doses of dexamethasone (DEX) on the growth and mineralisation of the skeletal system of piglets at weaning was considered in undertaking this study. Sows were treated i.m. with DEX at the dose of 0.03 mg kg−1 body weight every second day during the last 45 days of pregnancy. Prenatal treatment with DEX resulted in decreased weight, length, geometric parameters and histomorphometry of limb bones and influenced bone quality which was expressed by decreased values of bone mineral density (BMD), ultimate and maximum elastic strengths about 40%, 60% and 40%, respectively. Prenatal DEX administration to male piglets via their mothers significantly enhanced the concentration of leptin and decreased the concentration of GH and insulin. Additionally, the negative effect of DEX treatment on bone tissue was connected with changes of the free amino acid pool of male piglets. In addition, female pigs had unaffected mass and length of bones. This result showed that maternal DEX action was multifactorial and differently influenced postnatal bone development in the female and male piglets.