Lecture Notes: Fetal Assessment and Monitoring in Labor

Importance of Fetal Assessment

• Fetal monitoring is essential during labor to understand fetal health.
• Nurses use fetal monitors to track the fetal heart rate and contractions.
• Monitoring can be intermittent or continuous, depending on doctor's orders.
• Key objectives and exam questions may be based on fetal monitoring.

Electronic Fetal Monitoring

• Introduced in the 1970s, replacing fetoscopes and stethoscopes.
• Helps visualize fetal heart rate and contractions for over 80% of laboring patients.
• Aims to reduce long-term neurological effects, though research continues.

Types of Fetal Monitoring

External Fetal Monitoring

• Components: Ultrasound transducer (requires gel) and Toco transducer.
• Measures fetal heart rate and contraction frequency/duration but not strength.
• Placement involves identifying fetal position using Leopold's maneuvers.
• Interpreting Tracings:
  • Baseline heart rate: Normal is 110-160 bpm.
  • Variability types: Absent, Minimal, Moderate, Marked.
  • Accelerations: 15 bpm above baseline for at least 15 seconds.

Internal Fetal Monitoring

• Requires ruptured membranes (spontaneously or artificially).
• Components: Scalp electrode for heart rate and intrauterine pressure catheter for contractions.
• Provides exact contraction strength and helps calculate Montevideo units (MVUs).

Understanding Variability

• Absent Variability: No fluctuation, possibly indicating fetal demise.
• Minimal Variability: 0-5 bpm fluctuation, could indicate fetal sleep or narcotic effect.
• Moderate Variability: 5-25 bpm fluctuation, reassuring of fetal well-being.
• Marked Variability: >25 bpm fluctuation, significance unclear.

Decelerations

• Early Decelerations: Mirrors contraction, indicating head compression.
• Late Decelerations: Occur after contraction peak, indicating placental insufficiency.
• Variable Decelerations: Abrupt dips with quick recovery, indicating cord compression.
• Prolonged Decelerations: Lasts 2-10 minutes, requires intervention.
• Mnemonic for Decelerations: VEAL CHOP (Variable, Early, Accelerations, Late).

Intervention Strategies

• POISON mnemonic:
  • Position change, Oxygen, Increase IV fluids, Sterile exam, Turn off Pitocin, Notify provider.
• Amnioinfusion for oligohydramnios or variable decelerations.
• Tocolytics like Magnesium Sulfate and Terbutaline to relax uterine muscles.

Documentation and Categories

• Category 1: Reassuring, normal baseline, moderate variability, no decelerations.
• Category 2: Non-reassuring, variable decelerations, Bradycardia/Tachycardia, minimal variability.
• Category 3: Non-reassuring, requires intervention, sinusoidal pattern, absent variability.

Additional Notes

• Importance of a 20-minute tracing for accurate documentation.
• Proper documentation is crucial for legal and medical accuracy.
• Nurses should know their scope of practice based on state regulations.