STUDY GUIDE

ADVANCED STUDY GUIDE: Intrapartum & Fetal Surveillance

SECTION 1: Fetal Heart Rate (FHR) Deep Dive

1. The "Big Three" of FHR Assessment

• Baseline:

  • Normal FHR: 110–160 beats per minute (bpm).

  • Tachycardia: FHR > 160 bpm.

  • Usually indicates maternal fever or infection, specifically Chorioamnionitis.

  • Bradycardia: FHR < 110 bpm.

  • Often indicates prolonged cord compression or cord prolapse.

• Variability (The Most Important Indicator):

  • Variability reflects the interplay between the sympathetic and parasympathetic nervous systems.

  • Types of Variability:

  • Absent/Minimal Variability:

    • Can be due to:

    • The baby is asleep (20–30 minutes max).

    • Maternal medications, such as IV opioids (Stadol/Nubain).

    • Fetal acidosis.

    • Action Taken: Stimulate fetal scalp or change maternal position.

  • Moderate Variability (6–25 bpm):

    • This is the targeted goal, indicating that the fetus is well-oxygenated.

• Periodic Changes (VEAL CHOP):

  • Variable Decels (V-shape):

  • Characteristics: Abrupt drop in FHR.

  • Cause: Cord compression, possibly due to nuchal cord or low amniotic fluid.

  • Action Taken: Move the mother side-to-side or into a knee-chest position.

  • Early Decels:

  • Characteristics: Mirrors the contraction (starts and ends with it).

  • Cause: Head compression.

  • Action Taken: Considered benign. Only document and perform a vaginal exam to check progress.

  • Late Decels:

  • Characteristics: Starts after the peak of the contraction and returns to baseline post-contraction.

  • Cause: Uteroplacental insufficiency (the placenta isn’t providing enough oxygen).

  • Action Taken: This is a medical emergency. Implement LION protocol:

    • L: Position mother on left side.

    • I: Administer IV fluids.

    • O: Provide 10L of oxygen via mask.

    • N: Notify MD and stop Pitocin if it’s being administered.

2. Contraction Assessment (IUPC or Palpation)

• Frequency:

  • Measured from the start of one contraction to the start of the next.

  • Should not occur more frequently than once every 2 minutes.

• Duration:

  • Measured from the start to the finish of a contraction.

  • Should not exceed 90 seconds.

• Intensity:

  • Measured via Intrauterine Pressure Catheter (IUPC) in mmHg.

  • Normal labor intensity ranges from 40–70 mmHg.

• Resting Tone:

  • Should be <20 mmHg using IUPC or described as "soft" through palpation.

  • It is crucial that the uterus relaxes; prolonged contraction without relaxation can compromise fetal oxygenation.

SECTION 2: The 4 Stages of Labor (Critical Details)

Stage 1: Dilation

• Latent Phase:

  • Dilation from 0–5 cm.

  • Patient Behavior: Talkative, excited.

  • Nursing Priority: Education and encourage ambulation to facilitate labor.

• Active Phase:

  • Dilation from 6–7 cm.

  • Patient Behavior: Focuses inward and requires breathing assistance.

  • Nursing Priority: Administration of pain relief or an epidural.

• Transition Phase:

  • Dilation from 8–10 cm.

  • Patient Behavior: Irritable, expressing statements like "I can’t do this," and may experience nausea.

  • Nursing Priority: Remain at bedside for support and monitoring.

Stage 2: Expulsion

• Dilation: 10 cm.

• Patient Behavior: Active pushing phase.

• End Goal: Culminates in the birth of the baby.

Stage 3: Placental Delivery

• Timing: Occurs shortly after childbirth (approximately 5–30 minutes).

• Output: Ends with the delivery of the placenta.

Stage 4: Recovery

• Timing: First 2 hours post-birth.

• Priority Concern: Prevention of hemorrhage, typically through fundal massage.

SECTION 3: Antenatal Surveillance (The "How" and "Why")

1. Non-Stress Test (NST)

• Procedure: Continuous monitoring of FHR over a 20-minute period.

• Reactive (PASS):

  • Two accelerations in FHR during the 20 minutes.

• Non-reactive (FAIL):

  • Fails to meet the criteria.

  • Next Step: Proceed to Biophysical Profile (BPP).

2. Biophysical Profile (BPP)

• Scoring: Total score out of 10 points (2 points per category).

• Categories assessed include:

  1. Fetal breathing movements.

  2. Gross body movements.

  3. Fetal tone (flexion and extension).

  4. Reactive FHR (as determined from the NST).

  5. Amniotic fluid volume (AFV).

• Interpreting Scores:

  • Score of 8–10: Indicates a normal assessment.

  • Score of 0–4: Indicates the need for immediate delivery.

3. Amniocentesis vs. CVS

• Chorionic Villus Sampling (CVS):

  • Performed earlier (10–13 weeks gestation).

  • Indicated solely for genetic testing.

• Amniocentesis:

  • Conducted later (typically after 15 weeks gestation).

  • Can be used for genetic assessments or measuring the L/S ratio, which assesses fetal lung maturity.

  • A L/S ratio of 2:1 indicates mature fetal lungs.

SECTION 4: Positioning & Fetal Lie

• Presentation Types:

  • Cephalic Presentation: Head first; considered normal.

  • Breech Presentation: Buttocks first; typically necessitates a cesarean section (C-section).

• Determining Position (3 Letters):

  • 1st Letter: (R)ight or (L)eft side of mother’s pelvis.

  • 2nd Letter: Designates landmark — (O)cciput/Head or (S)acrum/Butt.

  • 3rd Letter: Direction — (A)nterior (baby's face facing mom's spine) or (P)osterior (baby’s face facing mom’s belly).

• Special Note:

  • Occiput Posterior (OP) presentations often lead to “back labor.”

  • Nursing Action for OP position: Position the mother on all fours or apply counter-pressure to the lower back.