What is the immediate management for a laboring patient who develops a non‑reassuring fetal heart rate tracing?

Management of Non-Reassuring Fetal Heart Rate Tracing

When a laboring patient develops a non-reassuring fetal heart rate tracing, immediately initiate a systematic sequence of intrauterine resuscitation measures starting with maternal repositioning, discontinuing oxytocin if infusing, administering oxygen, and performing a vaginal examination, while simultaneously preparing for expedited delivery if the tracing remains abnormal despite these interventions. 1, 2

Immediate Intrauterine Resuscitation Algorithm

The following interventions should be performed rapidly and systematically 1:

1. Change maternal position to left lateral to relieve potential cord compression and improve uteroplacental blood flow 1, 2, 3

2. Assess maternal vital signs (temperature, blood pressure, pulse) to identify maternal hypotension or fever that may contribute to fetal compromise 1

3. Discontinue oxytocin infusion immediately if in use, as this is the priority action for Category III tracings and addresses uterine hyperstimulation causing uteroplacental insufficiency 1, 2, 4

4. Initiate oxygen at 6 to 10 L per minute via face mask to improve fetal oxygenation, though this should be done concurrently with other measures rather than as a first-line solo intervention 1, 2, 4

5. Perform vaginal examination to check for cord prolapse, rapid fetal descent, or vaginal bleeding suggestive of placental abruption 1, 2

6. Administer intravenous fluid bolus if not already running, or give a bolus to improve maternal intravascular volume and uteroplacental perfusion 1, 4

7. Assess fetal pH status using fetal scalp stimulation or acoustic stimulation; an acceleration in response indicates fetal pH is at least 7.20 and suggests the fetus is not acidemic 1, 3

Pattern-Specific Interventions

For Recurrent Variable Decelerations

Administer amnioinfusion for recurrent moderate to severe variable decelerations, as this has been shown to reduce decelerations, cesarean delivery rates, low Apgar scores at five minutes, low cord arterial pH, and maternal/neonatal hospital stays greater than three days 1, 3

For Recurrent Late Decelerations

Prioritize stopping oxytocin and correcting maternal hypotension if present, as late decelerations indicate uteroplacental insufficiency from compromised placental blood flow 1, 4

For Tachysystole

Consider tocolytic agents such as terbutaline to transiently stop contractions, understanding that while this improves FHR tracings, there is no proven improvement in neonatal outcomes 1

Decision for Expedited Delivery

Prepare for operative vaginal delivery or cesarean delivery if the FHR tracing remains abnormal despite intrauterine resuscitation measures 1, 2, 4, 3

Category III Tracings Require Immediate Action

Category III tracings—defined as absent baseline variability with recurrent late or variable decelerations, bradycardia, or sinusoidal pattern—predict current or impending fetal asphyxia and mandate expedited delivery if resuscitation fails 1, 2, 4, 3

Timing Considerations

If delivery is imminent, even severe decelerations are less significant than in earlier stages of labor, and vaginal delivery may be appropriate if anticipated within minutes 1

Post-Delivery Management

Obtain cord blood gases after any delivery with abnormal FHR tracing to document the presence or absence of metabolic acidosis (cord pH less than 7.00 or base deficit greater than 12 mmol per L), which is one of four essential criteria for determining an acute intrapartum hypoxic event sufficient to cause cerebral palsy 1, 3

Critical Pitfalls to Avoid

• Do not delay definitive intervention when recurrent variable or late decelerations persist with absent variability despite resuscitation measures, as this represents Category III tracing requiring expedited delivery 2, 4, 3

• Do not use maternal oxygen as a first-line solo measure before attempting position changes and stopping oxytocin, as recent evidence suggests potential risks from oxygen free radical activity with uncertain long-term effects 5

• Do not fail to perform periodic reassessment of the FHR tracing after interventions, as management depends on fetal response and the ability to effect rapid delivery when necessary 1

• Do not overlook subtle late decelerations, which can be difficult to visualize but can be detected by holding a straight edge along the baseline 1

Documentation Requirements

Ensure adequate documentation with flow sheets, clinical pathways, or FHR tracing archival processes, with any written information on the tracing coinciding with automated processes to minimize litigation risk 1