EFFECT OF ETHANOL ON IMMATURE OVINE FETAL BREATHING MOVEMENTS, FETAL PROSTAGLANDIN E(2), AND MYOMETRIAL ACTIVITY

In the mature ovine fetus, ethanol decreases fetal breathing movements (FBM), which is temporally related to increased prostaglandin E(2) (PGE(2)) concentration, decreases blood glucose concentration, increases blood lactate concentration, and decreases uterine electromyographic (EMG) activity. The objective of this study was to determine the effects of ethanol on these variables in the immature fetal sheep. Experiments were conducted in pregnant ewes at 85-94 days of gestation (full term 147 days) that received a 1-h maternal infusion of 1 g ethanol/kg maternal body wt (n = 9) or an equivalent volume of saline (n = 5). The maximal maternal and fetal blood ethanol concentrations for the ethanol regimen were 1.305 +/- 0.165 and 1.458 +/- 0.137 mg/ml, respectively. Maternal infusion of ethanol (or saline) did not change the incidence of FBM, fetal plasma PGE(2) concentration, heart rate, blood pressure, blood gases and pH, or uterine EMG activity. Ethanol decreased (P < 0.05) fetal blood glucose concentration from 1.18 +/- 0.10 to 0.87 +/- 0.07 and 0.89 +/- 0.09 mM at 1 and 3 h, respectively, but did not alter blood lactate concentration compared with saline infusion. These data support the hypothesis that the effects of ethanol on FBM, fetal plasma PGE(2) and blood lactate concentrations, and uterine EMG activity are gestational age dependent.