The effect of continuous or pulsatile administration of oxytocin to ewes at 126 to 136 days' gestation on myometrial activity and fetal oxygenation

G. Pimentel, E. R. Poore, P. W. Nathanielsz

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

Oxytocin was infused either continuously or in pulses to pregnant ewes to compare the responses of myometrial activity (contractures) and changes in fetal arterial Po2. Group 1 (n = 5) was infused with saline solution throughout the experiment. In group 2 (n = 5) oxytocin was infused continuously (160 μU · kg-1 · min-1) for 7 days whereas group 3 (n = 5) ewes received 960 μU · kg-1 · min-1 for 5 minutes every 30 minutes for 7 days. Contracture frequency increased in both oxytocin-infused groups. With continuous infusion contracture frequency returned to preinfusion levels during the last 4 days of infusion, whereas with pulsatile infusion contracture frequency remained increased throughout the infusion period. Fetal arterial Po2 was decreased throughout the 7 days of infusion in both oxytocin-infused groups. Pulsatile group fetal arterial Po2 levels remained decreased after the oxytocin infusion was stopped. These findings show; (1) Myometrial response to oxytocin in late pregnant ewes is influenced by the mode of administration; (2) administration of oxytocin to pregnant ewes resulted in a decrease in fetal Po2, and thus fetal hypoxemia cannot be attributed exclusively to increased contracture frequency.

Original languageEnglish (US)
Pages (from-to)242-247
Number of pages6
JournalAmerican Journal of Obstetrics and Gynecology
Volume160
Issue number1
DOIs
StatePublished - Jan 1989
Externally publishedYes

Keywords

  • fetal oxygenation
  • myometrial activity
  • Oxytocin

ASJC Scopus subject areas

  • Obstetrics and Gynecology

Fingerprint Dive into the research topics of 'The effect of continuous or pulsatile administration of oxytocin to ewes at 126 to 136 days' gestation on myometrial activity and fetal oxygenation'. Together they form a unique fingerprint.

Cite this