Increased uteroplacental production of prostaglandin E2 during ethanol infusion.

Experiments were conducted in 14 pregnant sheep to determine the effect of a 1-h maternal infusion of ethanol (1 g/kg maternal body wt) on placental efflux of prostaglandin E2 (PGE2), umbilical blood flow (Qum), and carbohydrate metabolism at 123-130 days gestation. This ethanol dosage regimen produced peak ethanol concentrations in fetal and maternal blood in the range of 1.48-1.64 mg/ml at the end of the infusion. Umbilical venous and fetal arterial PGE2 concentrations increased (P < 0.05) from 315 +/- 47 and 202 +/- 25 pg/ml to 740 +/- 172 and 489 +/- 67 pg/ml, respectively, at the end of the infusion. Placental secretion of PGE2 into the fetal circulation increased by 45% (P < 0.05). Uterine venous and maternal arterial PGE2 concentration increased (P < 0.05) from 370 +/- 27 and 262 +/- 28 pg/ml to 705 +/- 51 and 487 +/- 69 pg/ml, respectively. Fetal and maternal blood glucose concentration decreased (P < 0.05) from 0.98 +/- 0.11 and 2.88 +/- 0.25 mmol/l to 0.81 +/- 0.21 and 2.44 +/- 0.16 mmol/l, respectively. Fetal and maternal blood lactate concentration increased (P < 0.05) from 1.40 +/- 0.11 and 0.68 +/- 0.07 mmol/l to 1.67 +/- 0.14 and 1.82 +/- 0.16 mmol/l, respectively. Qum, fetal heart rate, fetal blood pressure, and fetal and maternal blood gases were unchanged by the ethanol infusion. These results support the hypothesis that the placenta is the major source of the elevated fetal and maternal plasma PGE2 concentrations produced in pregnant sheep by maternal ethanol administration.