How is a concerning Cardiotocography (CTG) tracing in a pregnant woman with a history of previous obstetric complications and underlying medical conditions interpreted and managed?

Interpretation and Management of Concerning CTG in High-Risk Pregnancy

A concerning CTG tracing in a pregnant woman with previous obstetric complications and underlying medical conditions requires immediate obstetric and medical review, as emergency cesarean delivery may be necessary, and non-reassuring fetal status could be the first sign of maternal clinical deterioration. 1

Identifying Non-Reassuring CTG Patterns

The following patterns indicate potential fetal compromise and require urgent action:

• Fetal tachycardia: Baseline fetal heart rate persistently above 160 beats per minute 1
• Fetal bradycardia: Baseline fetal heart rate persistently below 110 beats per minute 1
• Loss of heart rate variability: Absence of normal beat-to-beat fluctuations in the fetal heart rate 1
• Variable decelerations: Abrupt decreases in fetal heart rate that vary in timing, depth, and duration 1
• Late decelerations: Gradual decreases in fetal heart rate with delayed onset after contraction begins, indicating uteroplacental insufficiency and fetal hypoxemia 1

Late decelerations are particularly concerning, especially when accompanied by loss of variability, as they are associated with fetal acidosis and increased risk of adverse neonatal outcomes. 1

Immediate Management Steps

When a non-reassuring CTG pattern is identified, implement the following interventions immediately:

• Administer supplemental oxygen to the mother 1
• Position the mother on her left side to improve uteroplacental perfusion 1
• Discontinue oxytocin if being administered 1
• Activate multidisciplinary team involving obstetrics, maternal-fetal medicine, and anesthesia 1

Context-Specific Interpretation in High-Risk Patients

Previous Obstetric Complications

In women with history of preeclampsia or fetal growth restriction, non-reassuring CTG patterns warrant particularly urgent evaluation, as delivery may be indicated. 1 Specifically:

• Preeclampsia with non-reassuring CTG is an indication for delivery 1
• Fetal growth restriction with absent or reversed end-diastolic velocity on umbilical artery Doppler combined with non-reassuring CTG requires delivery 1, 2

Maternal Critical Illness or Underlying Medical Conditions

Non-reassuring fetal well-being could be the first sign of deterioration of maternal clinical condition and may signify impending maternal decompensation. 1 In this context:

• Fetal surveillance provides a real-time measure of maternal end-organ perfusion 1
• CTG findings can help optimize maternal positioning, oxygenation, and mean arterial pressure 1
• Women with cardiovascular disease require management in specialized centers with multidisciplinary teams including experienced cardiologists, obstetricians, and access to cardiothoracic surgery 3

Fetal Growth Restriction

When CTG is concerning in the context of fetal growth restriction, integrate with Doppler findings:

• Increase CTG monitoring frequency to twice weekly or more when complicated by absent or reversed end-diastolic velocity 2
• Monitor 1-2 times per day with absent or reversed end-diastolic velocity 2
• Consider cesarean delivery for pregnancies with fetal growth restriction complicated by absent or reversed end-diastolic velocity 2

Delivery Decision Algorithm

Emergency cesarean delivery should be considered when:

• Late decelerations persist despite interventions, especially with loss of variability 1
• Non-reassuring CTG occurs in context of preeclampsia 1
• Fetal growth restriction with absent or reversed end-diastolic velocity shows non-reassuring patterns 1, 2
• Maternal cardiovascular decompensation is suspected based on fetal monitoring 1

Induction of labor with continuous CTG monitoring may be appropriate if umbilical end-diastolic flow is present and CTG patterns improve with initial interventions. 2

Critical Pitfalls to Avoid

• Never attribute non-reassuring CTG solely to maternal anxiety or positioning without implementing interventions and reassessing 1
• Do not rely on CTG alone in high-risk pregnancies; integrate with umbilical artery Doppler assessment when fetal growth restriction is suspected 2
• Avoid delaying delivery when significant abnormalities persist despite interventions, particularly in context of preeclampsia or abnormal Doppler studies 1, 2
• Do not fail to recognize that fetal compromise may indicate maternal deterioration in women with underlying medical conditions 1

Ongoing Surveillance Requirements

For high-risk patients with initially reassuring CTG:

• Women with cardiovascular disease require repeated assessments at regular intervals throughout gestation 3
• Fetal growth restriction with normal Doppler requires weekly CTG monitoring after viability 2
• Abnormal umbilical artery Doppler requires at least weekly CTG monitoring 2
• Patients with ascending aorta dilatation require repeated echocardiographic imaging every 4-8 weeks 3