wk 6 (recorded lecture) ~ Fetal Monitoring

Introduction to Fetal Assessment
- Focus on fetal monitoring specifically during labor, distinguishing from NST (Non-Stress Test) assessments.
- Importance of understanding that criteria for assessment differs in labor settings.

Purpose of Leopold's Maneuver
- To determine the position of the fetus during labor.
- Positions include:
  - Longitudinal
  - Perpendicular
  - Parallel
  - Oblique
  - Transverse
- Identify if the presenting part is vertex or breech.
- Assess whether the presenting part is engaged in the pelvis or remains high and floating.
- Key focus for monitoring: locate fetal back to enable accurate heart rate tracing with external monitors.

Fetal Heart Rate
- Fetal heart rate responds to demands by increasing or decreasing, unlike adults who can modify contractility among other factors.
Central Nervous System Development
- Completed by week 10, involving sympathetic and parasympathetic systems:
- Sympathetic: responsible for increasing heart rate (speedy).
- Parasympathetic: responsible for decreasing heart rate (pokey).
Baroreceptors and Chemoreceptors
- Baroreceptors:
- Sensitive to pressure changes in the fetal circulatory system.
- Trigger heart rate changes based on circulation pressure (e.g., fetal blood loss due to abruption).
- Chemoreceptors:
- Sensitive to CO2 levels and oxygenation.
- Affect heart rate based on the balance of these gases.
- Assessment of heart rate variability indicates CNS responsiveness to incoming information.

Fetal Heart Rate Strips
- Comprised of two main sections: contractions and fetal heart rate components.
- Fetal heart rate serves as an indirect assessment of fetal oxygenation, emphasizing the importance of oxygen flow from the mother to the fetus.
- Uterine contractions significantly affect oxygen delivery; thus, both heart rate and contractions should be monitored concurrently.
Frequency of Monitoring
- Intermittent Auscultation:
- Utilizes a handheld Doppler for short assessments (60 seconds).
- Not all patients qualify, primarily low-risk patients.
- Intermittent monitoring may occur every 15-30 minutes, or hourly in latent labor.
- Continuous Monitoring:
- Required for higher risks or when patients are receiving medications affecting labor augmentation (like Pitocin).
Evaluating Fetal Monitoring Strips
- Assessment of four key areas:
- Baseline heart rate (normal range: 110-160 bpm).
- Variability: fluctuation in heart rate.
- Accelerations: increases in heart rate.
- Decelerations: decreases in heart rate.

Interpreting Fetal Monitoring Strips
- Example of fetal heart rate strip and contraction tracing:
- Contraction tracing at the bottom with vertical lines indicating pressure changes in millimeters of mercury (mmHg).
- Fetal heart rate tracing at the top, with horizontal lines displaying 10 bpm increments.
Baseline Heart Rate Analysis:
- Average heart rate observed over a 10-minute window.
- Normal range is 110 to 160 bpm, aberrations may denote inadequate perfusion.
Variability:
- Definition: fluctuation in heart rate amplitude and frequency.
- Absent Variability: no fluctuations, suggests critical fetal oxygenation issues.
- Minimal Variability: fluctuations of less than 5 bpm.
- Moderate Variability: 6-25 bpm fluctuation—indicates healthy fetal neurologic response.
- Marked Variability: fluctuation exceeding 25 bpm—may indicate distress.

Accelerations:
- An increase of 15 bpm or more for 15 seconds, occurring when the fetus moves and requires more oxygen.
Decelerations Types:
- Early Decelerations: Gradual drop correlating with uterine contractions (mirror image), indicating fetal head compression (vagal response).
- Late Decelerations: Gradual decrease starting at peak contraction, indicating placental insufficiency.
- Variable Decelerations: Abrupt drops (less than 30 seconds) indicating cord compression; must be monitored carefully.
- Prolonged Decelerations: Drop in heart rate for more than two minutes indicating potential fetal distress.

Category One: Normal
- Baseline 110-160 bpm, moderate variability; may include accelerations or early decelerations, without late or variable decelerations.
Category Two: Indeterminate
- Can include variability issues, bradycardia/tachycardia, or different deceleration types, necessitating close monitoring.
Category Three: Abnormal
- Contains absent variability with recurrent late or variable decelerations, bradycardia, and sinusoidal patterns indicating significant fetal distress needing immediate intervention.

Key Concepts in Contraction Monitoring:
- Frequency: time from the start of one contraction to the start of the next.
- Duration: length from contraction onset to conclusion.
- Resting Tone: interval of uterine rest, crucial for fetal oxygen replenishment.
- Important to utilize palpation techniques to correspond monitor readings with actual contractions.

Actions During Fetal Monitoring:
- Repositioning: Shift patient to alternate sides or hands and knees to improve oxygenation.
- Fluid bolus: Administer increased fluids to promote perfusion.
- Administer Oxygen: Only if indicated by maternal hypoxia.
Further Considerations:
- Assess contractions for frequency, strength, and reasons behind fetal heart rate changes.
- Conditions like cord prolapse, uterine rupture, and abruption need to be quickly identified and acted upon.

Fetal monitoring involves real-time assessment and the interpretation of the fetal strip during labor to categorize the state of fetal health and oxygenation.
Understanding the dynamics of contractions alongside fetal heart rate is integral for ensuring appropriate nursing interventions to support fetal well-being.