Antenatal glucocorticoid therapy increases glucose delivery to cerebral circulations during acute hypoxemia in fetal sheep during late gestation.

Abstract

To determine the effects of 2 maternal injections with dexamethasone on the calculated oxygen and glucose deliveries to fetal cerebral and peripheral circulations during acute hypoxemia in sheep. Beginning at 124 days, ewes received 2 intramuscular injections of either dexamethasone (2 x 12 mg, n = 10) or saline solution (2 x 2 mL, n = 12) 24 hours apart. Hypoxemia (1 hour) was induced 32 hours after the first injection (H1) and 3 days after the second (H2). In saline solution-treated fetuses, glucose delivery was unchanged or increased in femoral and carotid circulations, respectively, during H1 and H2. In dexamethasone-treated fetuses, the increase in glucose delivery to the head tended to be greater during H1 and was significantly enhanced in dexamethasone- vs saline solution-treated fetuses during H2. Two maternal injections with dexamethasone significantly enhanced glucose delivery to the head during acute hypoxemia in the ovine fetus.