What is the immediate management for a primigravida (first-time mother) in labor with recurrent late decelerations and reduced variability on Cardiotocography (CTG) after oxytocin administration?

Immediate Management: Stop Oxytocin

The immediate management for this primigravida with recurrent late decelerations and reduced variability on CTG after oxytocin administration is to stop the oxytocin infusion (Option D). This clinical presentation represents a Category III fetal heart rate tracing indicating uteroplacental insufficiency and potential fetal hypoxia, requiring urgent intervention 1.

Rationale for Stopping Oxytocin First

Discontinuing oxytocin is the priority initial action before considering other measures or delivery, as it addresses the root cause of uterine hyperstimulation leading to uteroplacental insufficiency 1. The American College of Obstetricians and Gynecologists explicitly recommends stopping the oxytocin infusion as the first intervention for Category III fetal heart rate tracings 1.

The FDA labeling for oxytocin mandates that "the oxytocin infusion should be discontinued immediately in the event of uterine hyperactivity or fetal distress" 2. This is critical because:

• Recurrent late decelerations combined with reduced variability indicate uteroplacental insufficiency 1, 3
• The physiology involves inadequate oxygen delivery to the fetus through the placenta, often caused by uterine hyperstimulation (tachysystole) from oxytocin 3
• When properly stopped, oxytocic stimulation of the uterine musculature will soon wane 2

Complete Intrauterine Resuscitation Algorithm

While stopping oxytocin is the first and most critical step, comprehensive management includes simultaneous resuscitative measures 1, 3:

1. Stop oxytocin immediately to reduce uterine activity and improve uteroplacental blood flow 1, 3

2. Change maternal position to left lateral to relieve potential cord compression and optimize placental perfusion 1, 3

3. Administer oxygen at 6-10 L/min via face mask to improve fetal oxygenation 1, 3, 2

4. Give IV fluid bolus if not already administered to ensure adequate maternal hydration 3

5. Assess maternal vital signs and treat hypotension if present to ensure adequate uteroplacental perfusion 3

6. Perform vaginal examination to assess for rapid descent, cord prolapse, or signs of uterine rupture 4

Why Other Options Are Secondary

Cesarean section (Option A) is not the immediate first step. Continuous monitoring after stopping oxytocin is crucial to assess response to intervention 1. If the tracing improves, labor may continue with close monitoring, but if it remains abnormal despite resuscitative measures, expedited delivery via operative vaginal delivery or cesarean section should then be considered 1.

Maternal position change (Option B) and oxygenation (Option C) are important supportive measures that should be done simultaneously with stopping oxytocin, but they do not address the root cause of uterine hyperstimulation 1, 3. These are components of intrauterine resuscitation but are secondary to discontinuing the causative agent.

Critical Pitfall to Avoid

The most common error is attempting other resuscitative measures while continuing oxytocin infusion. The oxytocin must be stopped first because continued administration perpetuates the uterine hyperstimulation causing the uteroplacental insufficiency 1, 2. Even with proper administration and adequate supervision, hypertonic contractions can occur in patients whose uteri are hypersensitive to oxytocin 2.

Monitoring After Intervention

After stopping oxytocin and implementing resuscitative measures, continuous fetal heart rate monitoring is essential 1, 4. If severe hyperstimulation with fetal heart rate abnormalities persists, consider tocolysis with terbutaline to reduce uterine tone 4, 5. Prepare for expedited delivery if the abnormal pattern persists despite all interventions 1, 3.