Fetal Monitoring

Intrapartum Fetal Surveillance & Nursing Care During Labor and Birth

Introduction

• Primary Goal:

  • Enable clinicians to assess adequacy of fetal oxygenation during labor.

• Methods of Surveillance:

  • Low-Technology Methods:

  • Fetoscope or doppler for assessing fetal heart rate (FHR).

  • Palpation of uterine contractions.

  • High-Technology Methods:

  • Electronic fetal monitoring (EFM).

• Information Gathered:

  • Evaluation of fetal oxygenation based on bedside assessments and accurate interpretation of the data.

  • Deciding when physiologically based conservative corrective measures are necessary to correct interruptions in the oxygenation pathway.

  • Providing a continuing mechanism to optimize communication amongst health care team members and clients.

  • Supporting clinical decision-making in a shared decision-making model, promoting effective communication, client safety, and improving health care quality.

Fetal Oxygenation

• Requirements for Adequate Fetal Oxygenation:

  • Sufficient maternal blood flow and volume to the placenta.

  • Normal maternal oxygen saturation.

  • Adequate placental exchange of oxygen and carbon dioxide.

  • An open circulatory path from placenta to fetus through umbilical cord vessels.

  • Normal fetal circulatory and oxygen-carrying functions.

• Effects of Interruptions:

  • Interruptions at one or more points can cause changes in FHR.

Autonomic Nervous System

• Overview:

  • Neural network assisting with maintaining physiological stability, also known as homeostasis.

• Branches:

  • Parasympathetic:

  • Originates in the brainstem, distributed through the vagus nerve and heart.

  • Controls baseline FHR and FHR variability.

  • Sympathetic:

  • Originate in fetal myocardium, increasing fetal cardiac output.

  • Increases FHR baseline.

  • Poor oxygenation leads to release of catecholamines.

Fetal Heart Rate Variability

• Definition:

  • Fetal heart rate variability (FHRV) reflects changes in the variance over time between consecutive heartbeats and is the most critical predictor of adequate fetal oxygenation.

• Importance of Variability:

  • Adequate oxygenation promotes normal function of the autonomic nervous system (ANS).

  • Helps fetus maintain homeostasis during labor.

  • Variability evaluates the function of the fetal ANS.

Baroreceptors and Chemoreceptors

• Baroreceptors:

  • Located in the carotid arch and aortic sinus.

  • Pressure-sensitive stretch receptors that respond to blood pressure changes.

  • Signal the brainstem to modify FHR for blood pressure management.

• Chemoreceptors:

  • Located in the medulla oblongata and aortic/carotid bodies.

  • Sensory nerve endings stimulated by alterations in fetal oxygen, carbon dioxide, and blood pH levels.

  • Elicit a sympathetic response, regulating FHR.

Intermittent Auscultation and Palpation

• Used for:

  • Low-risk patients.

  • Effective if performed consistently following professional guidelines.

• Assessment Focus:

  • FHR: observing regularity (regular or irregular), increases or decreases.

  • Uterine contractions: assessing frequency, duration, intensity, resting tone, and relaxation time.

  • Important to listen to FHR before, during, and after contractions to comprehensively evaluate.

Bedside Fetal Monitor and Transducers

• Function:

  • Collect FHR and uterine activity (UA) information for visual output (numeric display and graphic strip).

  • Ability to record twins and triplets on the same graphic strip.

• Remote Surveillance:

  • FHR: Doppler (ultrasound) used, gel needed.

  • UA: Tocado dynamically (toco) placed usually near fundus.

• Internal Monitors:

  • Fetal Spiral Electrode (FSE): Screwed into the scalp of the fetus for direct heart rate monitoring.

  • Intrauterine Pressure Catheter (IUPC): Thin catheter inserted into the uterus to monitor changes in intrauterine pressure.

How To Read a Fetal Strip

• Components:

  • Fetal Heart Rate (FHR).

  • Contraction Pattern.

• Reading Mnemonic:

  • Muscle memory and consistent approach are critical; never forget a step.

Baseline FHR

• Normal Range:

  • 110-160 bpm, averaged over at least 2 minutes.

• Abnormal Conditions:

  • Tachycardia and bradycardia must be evaluated for normality.

  • If concerned, maternal pulse oximetry can be applied.

Variability

• Definition:

  • Variability is the best indicator of fetal oxygenation; fluctuations in FHR over time.

• Categories of Variability:

  • Absent: Undetectable amplitude change.

  • Minimal: Range of 1-5 bpm.

  • Moderate: Range of 6-25 bpm.

  • Marked: >25 bpm with a chaotic appearance.

  • Sinusoidal: An undulating, smooth, wave-like pattern (not true variability).

Accelerations

• Definition:

  • Audible or visual increases in FHR from baseline.

  • Increase by 10 bpm and lasts at least 10 seconds; for fetuses less than 32 weeks, the increase is by 15 bpm lasting for 15 seconds minimum.

Decelerations

• Definition:

  • Decreases in FHR from baseline.

• Types:

  • Recurrent: Occurs with >50% of contractions in a 20-minute period.

  • Early Decelerations: Onset to nadir is ≥ 30 seconds; nadir coincides with peak of contraction.

  • Late Decelerations: Onset to nadir is ≥ 30 seconds; nadir occurs after the peak of contraction.

  • Variable Decelerations: Abrupt decrease ≥ 15 bpm below baseline and ≥ 15 seconds long.

  • Prolonged Deceleration: Decrease ≥ 15 bpm below baseline lasting > 2 minutes.

Memory Trick for Deceleration Types

• V - variable

• E - early

• A - acceleration

• L - late

• C - cord compression

• H - head compression

• O - okay!

• P - placental insufficiency.

Categories of FHR Patterns

• Developed by NICHD to help predict fetal heart rate tracings requiring intervention to prevent poor outcomes:

  • Category 1: Normal baseline, moderate variability, without late or variable decelerations (considered normal). Can have accels and early decels

  • Category 2: Everything in between (indeterminate).

  • Category 3: Absent variability and recurrent late decels or variable decels or bradycardia, OR sinusoidal pattern (considered abnormal). Requires immediate intervention.

• Criteria for Category I:

  • Baseline rate 110 to 160 bpm; moderate baseline variability; late or variable decelerations absent; early decelerations may be present or absent.

Contraction Pattern

• Assessment:

• Count contractions in a 10-minute period, averaging over 30 minutes.

• Frequency Determination:

• Count from the beginning of one contraction to the beginning of the next. - Normal: ≤ 5 contractions per 10-minute period.

• Length of Contractions:

• Count how long the shortest and longest contractions last; ideally, there should be a 60-second break between contractions.

FHR Management

• Frequent Assessment:

  • Monitor oxygen pathway, identifying areas of potential interruption.

• Possible Interventions Include:

  • Changing maternal position.

  • Administering bolus IV fluids.

  • Supplementing oxygenation.

  • Reducing uterine activity.

  • Correcting blood pressure.

  • Modifying pushing efforts.

Nursing Care During Labor and Birth

Admission Responsibilities

• Top 3 Assessments:

  1. Fetal heart rate.

  2. Maternal vital signs.

  3. Impending birth.

• Additional Assessment Data Required:

  • Database/chart information.

  • Hands-on assessment: heart and lungs, abdomen, deep tendon reflexes (DTRs), general appearance.

  • Labs and IV setup (CBC, CMP, UA, T&S, & 18ga).

  • Questions regarding situation: contractions, fluid status, illness, current medications, etc.

Admission Therapeutic Relationship

• Building confidence and trust with the patient.

• Providing comfort through touch.

• Understanding cultural values.

• Involving family expectations and participation where possible.

• Discussing preferred names, birth plan, pain management plan, and feeding plan.

When to Update the Provider

• Upon admission during assessment.

• When consent forms are signed.

• During ongoing assessments.

Types of Admission

1. Planned:

   • Induction or scheduled cesarean delivery.

2. Unplanned:

   • Triage for evaluation of spontaneous labor or any concern leading to hospital admission (e.g., contractions, ruptured membranes, bleeding).

Unplanned Admission Scenarios

Reasons to Come to Hospital for Evaluation

• Contractions, ruptured membranes, bleeding, decreased fetal movement, or other concerns leading to discomfort at home.

Evaluation Criteria During Admission

• Labor status.

• Membrane status.

• Fetal well-being.

R/O Condition from Clinic

• Patients may come to the hospital for evaluation due to complications such as:

  • Gestational diabetes mellitus (GDM).

  • Pre-eclampsia.

  • Gestational hypertension (GHTN).

  • Poor fetal oxygenation.

  • Infection.

• Therapeutic Relationship:

  • Focus on alleviating anxiety and fear due to unknowns, providing support.

Planned Induction of Labor

Cervical Ripening

• Importance of cervical ripeness for effective contractions.

• Bishop Score applied to assess cervix suitability.

• Medications Used:

  • Prostaglandin: Misoprostol (Cytotec).

  • Mechanical Methods:

  • Membrane stripping.

  • Transcervical balloon catheter (Cook catheter or SLF).

Oxytocin Administration

• Goal:

  • To bring on contractions strong enough to cause cervical dilation.

• Administration:

  • Continuous infusion, usually starting at 2mu/min, increasing every 30 minutes with Cat I tracing.

• Nursing Considerations:

  • Monitor fluid status, fetal oxygenation, and maternal vital signs.

Membrane Rupture Assessment

• SROM vs. AROM documentation required.

  • Note time, FHR, color, odor, and quantity.

  • Normal Findings: Clear, possibly with vernix.

  • Abnormal Findings: Green, bloody, foul-smelling, or yellow/cloudy.

• Risks: Cord prolapse, infection, placental abruption.

Operative Vaginal Delivery

• Objective: Achieve vaginal delivery with rapid fetus delivery if poor fetal oxygenation is identified.

• Choice should involve provider and patient discussion with informed consent.

• Nursing Responsibilities:

  • Thorough documentation.

  • Preparation for newborn resuscitation and potential cesarean section (C/S).

Planned Cesarean Delivery

Statistics and Considerations

• US C/S Rate: 32.4%; Alaska: 22%.

• Discussion around indications, contraindications, and associated risks.

• Importance of emotional support, teaching, and promoting safety during the procedure.

Trial of Labor After Cesarean (TOLAC)

• Not all patients are candidates; provider evaluates probability of success using a specific calculator.

• Successful outcome leads to vaginal birth after cesarean (VBAC).

Versions

External Cephalic Version (ECV)

• Purpose: To change fetal position to enhance the chance of vaginal birth.

• Consideration of contraindications and risks during the procedure.

• Internal Version:

  • Typically performed for the second twin during delivery.

Nursing Care after Birth: Baby

• Goals:

  • Maintain cardiopulmonary function.

  • Support thermoregulation.

  • Identify and medicate as needed.

  • Assist with feeding, provide teaching, and ensure thorough charting.

Nursing Care after Birth: Client

• Assessment Areas:

  • Observe for hemorrhage; monitor vital signs, fundus, bladder, lochia, and perineal/labial areas.

  • Promotion of patient comfort, postoperative care, teaching, and documentation of nursing activities.