Prenatal or postnatal corticosteroids favor clinical, respiratory, metabolic outcomes and oxidative balance of preterm lambs corticotherapy for premature neonatal lambs.

Challenges of the extrauterine environment can be life threatening for a premature fetus with inadequate fetal maturity. Maternal corticosteroids therapy is widely employed to induce fetal pulmonary maturation. Nevertheless, whenever therapeutic pregnancy interruption has to be performed in a time manner insufficient to treat the dam, postnatal corticotherapy can be considered an alternative. However, it is not known if antenatal and postnatal corticotherapy can improve similarly neonatal outcomes and pulmonary function. This research aimed to analyze antenatal and postnatal corticotherapy on premature lambs vitality, pulmonary functioning, metabolic and oxidative status. Lambs were evaluated according to the mode of treatment: Prenatal Corticosteroid Group (8 lambs born after maternal betamethasone treatment 48 h prior to birth), Postnatal Corticosteroid Group (9 lambs subjected to betamethasone treatment 10 min after birth) and Control Group (5 lambs remained untreated). Lambs were medically followed-up from birth to 72 h thereafter through a complete physical examination, as well as lactatemia, glycaemia, blood acid-base balance and antioxidant status. Treated lambs had higher vitality score than the Control Group. Heart rate was higher in postnatal therapy compared to prenatal treatment. Respiratory rate and rectal temperature were higher in treated groups. Treated lambs had hyperglycemia, while the Postnatal Group had higher lactatemia than the Control Group. The Prenatal Group had lower and normal pCO2 from 60 min onwards. The Postnatal Group had higher superoxide dismutase activity than untreated lambs. In conclusion, prenatal and postnatal betamethasone treatments favor neonatal clinical outcome, respiratory function, glucose homeostasis and oxidative balance.