What is the best course of action for a mother in active labor with recurrent late decelerations and reduced variability on the Cardiotocography (CTG) tracing while receiving oxytocin?

Immediate Management: Stop Oxytocin First

The immediate priority is to discontinue the oxytocin infusion (Option A), as this addresses the root cause of uteroplacental insufficiency in this clinical scenario. 1, 2

Clinical Context and Rationale

This patient presents with a Category III fetal heart rate tracing characterized by recurrent late decelerations combined with reduced variability while receiving oxytocin. 3, 1 This pattern indicates:

• Uteroplacental insufficiency - Late decelerations occur when the nadir of deceleration follows the peak of contraction, reflecting inadequate placental oxygen delivery 3
• Potential fetal hypoxia or acidemia - The combination of recurrent late decelerations with reduced variability signifies absent baseline FHR variability requiring immediate intervention 3, 1
• Likely oxytocin-induced uterine hyperstimulation - The FDA labeling explicitly states that oxytocin infusion should be discontinued immediately in the event of uterine hyperactivity or fetal distress 2

Evidence-Based Management Algorithm

Step 1: Stop Oxytocin Immediately (Priority Action)

• Discontinue the oxytocin infusion as the first intervention before considering other measures or delivery 1, 4
• This addresses uterine hyperstimulation (tachysystole), which is the most likely cause of uteroplacental insufficiency in this oxytocin-receiving patient 1, 2
• The NICHD and ACOG guidelines consistently prioritize stopping oxytocin for Category III tracings 1
• Oxytocic stimulation of the uterine musculature will wane soon after abrupt cessation 3

Step 2: Simultaneous Resuscitative Measures

While stopping oxytocin is the priority, implement these measures concurrently:

• Reposition to left lateral position to relieve potential cord compression and improve uteroplacental blood flow 1, 4
• Administer oxygen at 6-10 L/min via face mask to improve fetal oxygenation 1, 4, 2
• Assess maternal vital signs and treat hypotension if present to ensure adequate uteroplacental perfusion 3, 4
• Perform vaginal examination to assess labor progress 3, 4
• Administer IV fluid bolus if not already given 3, 4

Step 3: Continuous Monitoring and Reassessment

• Monitor the fetal heart rate tracing continuously after stopping oxytocin to assess response to intervention 1
• If the tracing improves and variability returns, labor may continue with close monitoring 1
• If the tracing remains abnormal despite intrauterine resuscitation, prepare for expedited delivery via operative vaginal delivery or cesarean section 3, 1

Why Not Immediate Cesarean Section?

• Category III tracings require intervention to resolve the abnormal pattern or move toward expeditious delivery - not automatic cesarean 3
• Stopping oxytocin often rapidly improves the tracing since uterine hyperstimulation is reversible 1, 2
• Immediate cesarean without attempting intrauterine resuscitation exposes the mother to unnecessary surgical risks when the problem may resolve with conservative measures 1

Critical Pitfalls to Avoid

• Do not delay stopping oxytocin while only repositioning the patient - oxytocin discontinuation must be the first action 1, 2
• Do not continue oxytocin at a reduced rate - it must be completely discontinued 2
• Do not fail to prepare for expedited delivery if the pattern persists despite stopping oxytocin and implementing resuscitative measures 3, 1
• Do not assume repositioning alone will resolve late decelerations caused by oxytocin-induced uterine hyperstimulation - the underlying cause must be addressed 1, 4

Physiological Basis

• Late decelerations reflect uteroplacental insufficiency with delayed timing where oxygen delivery through the placenta is compromised 3, 4
• Oxytocin-induced uterine hyperstimulation reduces the resting interval between contractions, limiting placental reperfusion and fetal oxygenation 2, 5
• Reduced variability combined with late decelerations indicates the fetus is decompensating and no longer maintaining normal baseline variability despite ongoing hypoxic stress 6