Fetal and maternal sheep hypothalamus pituitary adrenal axis responses to chronic binge ethanol exposure during the third trimester equivalent

Background: We tested the hypothesis that in utero ethanol exposure results in changes in fetal and maternal adrenocorticotropin (ACTH) and cortisol d uring the third trimester equivalent, by using a chronically instrumented f etal sheep model. Methods: Pregnant ewes received saline or ethanol intravenously 3 consecuti ve days per week from day 109 to day 132 of gestation. Fetal and maternal b lood samples were collected on days 118 and 132. Results: Maternal and fetal ACTH and cortisol values increased on days 118 and 132 of gestation in response to ethanol infusions that created blood et hanol concentrations (BECs) that are easily achievable by human drinkers. P eak ACTH and cortisol values were detected 30 to 60 min after peak BECs wer e achieved. Conclusions: Chronic ethanol exposure during the third trimester equivalent in sheep resulted in repeated activation of the hypothalamus-pituitary-adr enal axis in both the mother and fetus. Temporally, the patterns of materna l and fetal responses to ethanol infusion were similar. We conclude that ov ine maternal ethanol exposure during the third trimester equivalent increas es fetal ACTH and cortisol concentrations, hormonal responses that may play a role in mediating alcohol-related birth defects.