pubmed-article:2991411 | pubmed:abstractText | Uterine contractions, induced by the administration of oxytocin to sheep between d 123-144 of pregnancy, were associated with a mean transient decrease in fetal PaO2 of 2.8 mm Hg within 5 min. These changes were associated with a rapid increase in the concentration of ACTH in fetal plasma. There was a significant (P less than 0.05) increase in the percentage change (+40 to +47%) over basal ACTH levels in fetal plasma at +5, +15 and +20 min after oxytocin. Administration of saline had no significant effect on intrauterine pressure, fetal PaO2 or fetal plasma ACTH levels. We speculate that increases in uterine activity and/or transient decreases in fetal PaO2 may contribute to short-term fluctuations in plasma ACTH in fetal sheep. | lld:pubmed |