oxytocin challenge test
Pronunciation: ok-see-TOH-sin
Antepartum fetal surveillance test using synthetic oxytocin to evaluate fetal response to uterine contractions.
Full Definition
The oxytocin challenge test (OCT) is a method of antepartum fetal assessment that evaluates fetal reserve by observing fetal heart rate response to induced uterine contractions. The test involves intravenous oxytocin administration to achieve three moderate contractions within a 10-minute period while monitoring fetal heart rate patterns. Results are classified as negative (reassuring), positive (concerning for uteroplacental insufficiency), suspicious, or unsatisfactory. A positive test suggests fetal hypoxia during contractions and may indicate need for delivery. Due to risks of uterine hyperstimulation and preterm labor, OCT is generally reserved for specific high-risk situations when other testing methods are inadequate.
Usage
Usage note: Also known as contraction stress test (CST). Often abbreviated as OCT.
In Context
- "The oxytocin challenge test revealed late decelerations suggestive of uteroplacental insufficiency." — High-risk pregnancy monitoring
- "A negative oxytocin challenge test provided reassurance about fetal well-being at 40 weeks gestation." — Antepartum surveillance report