What is the most important intervention for a fetus with bradycardia and prolonged contraction during labor induction?

Management of Fetal Bradycardia with Prolonged Contraction During Labor Induction

The most important immediate intervention is to administer subcutaneous terbutaline to stop uterine hyperstimulation, while simultaneously preparing for urgent cesarean section if the bradycardia does not resolve rapidly. 1, 2

Immediate Intrauterine Resuscitation Sequence

This clinical scenario represents uterine hyperstimulation (contraction lasting 2 minutes) with resultant fetal bradycardia (heart rate drop to 80 bpm) following prostaglandin gel administration. The priority is to reverse the reversible cause while preparing for definitive intervention.

First-Line Actions (Perform Simultaneously):

• Discontinue the uterotonic agent - Stop any oxytocin infusion if running (though in this case, only prostaglandin gel was applied) 1, 2

• Administer subcutaneous terbutaline - This tocolytic agent transiently stops contractions and has been shown to improve fetal heart rate tracings in uterine hyperstimulation, which is a potentially reversible cause of fetal bradycardia 1, 2

• Administer oxygen at 10 L/min by facemask - Maternal oxygenation has demonstrated significant effect on increasing fetal oxygen in abnormal FHR patterns 1, 2

• Change maternal position - Implement left lateral uterine displacement to relieve potential aortocaval compression 1, 2

• Assess for cord prolapse - Perform immediate vaginal examination to rule out umbilical cord prolapse, which would be an irreversible cause requiring immediate cesarean delivery 1, 2

Critical Decision Point: Reversible vs. Irreversible Causes

The 2015 Anaesthesia guidelines distinguish between potentially reversible and irreversible causes of fetal bradycardia, which fundamentally determines management urgency 1:

Potentially Reversible Causes (attempt intrauterine resuscitation first):

• Uterine hyperstimulation (this case)
• Hypotension after epidural
• Aortocaval compression 1

Irreversible Causes (proceed directly to cesarean):

• Umbilical cord prolapse with sustained bradycardia
• Major placental abruption
• Ruptured uterine scar with placental/fetal extrusion
• Fetal hemorrhage 1

Preparation for Urgent Cesarean Section

While performing intrauterine resuscitation, simultaneously prepare for urgent cesarean delivery. 1, 2, 3

• In cases of sustained fetal bradycardia, delivery by cesarean section within 25 minutes improves long-term neonatal neurologic outcome 3

• The American College of Obstetricians and Gynecologists recommends expedited delivery via operative vaginal delivery or cesarean section if the FHR tracing remains abnormal despite intrauterine resuscitation measures 2

• Fetal condition is likely to be maintained during a delay in the majority of cases with potentially reversible causes, in contrast to irreversible causes where there is significant decline in neonatal pH with increasing bradycardia-delivery interval 1

Why Each Option Ranks as It Does:

Terbutaline administration addresses the root cause (uterine hyperstimulation from prostaglandin) and may rapidly reverse the bradycardia, avoiding cesarean section entirely 1, 2

Oxygen administration is essential but supportive rather than definitive for uterine hyperstimulation 1, 2

Cord prolapse assessment is critical to rule out an irreversible cause, but if absent (as is statistically more likely), does not solve the problem 1, 2

Urgent cesarean preparation is necessary but should occur simultaneously with attempts at intrauterine resuscitation for potentially reversible causes 1, 2

Common Pitfalls to Avoid:

• Do not delay tocolytic administration while waiting to see if other measures work - uterine hyperstimulation requires active reversal 1, 2

• Do not proceed immediately to cesarean without attempting intrauterine resuscitation when the cause is likely reversible (prostaglandin-induced hyperstimulation) 1

• Do not fail to prepare for cesarean while attempting resuscitation - both must occur simultaneously 1, 2, 3

• Do not use terbutaline for prolonged tocolysis - it is FDA-approved only for acute bronchospasm, not for maintenance tocolysis, and carries serious maternal risks including cardiac arrhythmias, pulmonary edema, and myocardial ischemia when used for prolonged tocolysis 4