Electronic Fetal Monitoring (EFM)

Overview of Electronic Fetal Monitoring (EFM)

• Methodology and Purpose: Fetal monitoring is conducted electronically to provide continuous data on the fetal status during labor and delivery. It serves as the primary mode of communication between the fetus and the medical staff while the baby is still in utero.

• Display and Accessibility: Monitoring is visible on screens located at the nursing station and within the patient's room. The data appears as a series of tracings (‘squiggly lines’).

• Clinical Indicators: EFM allows clinicians to evaluate several critical factors:     * Contraction patterns and uterine activity.     * Fetal oxygenation status.     * Fetal neurological status.     * Fetal cardiac status.

• Documentation and Off-site Review: Tracings are electronically uploaded to the patient's medical chart. They can be printed to paper if necessary for medical records or remote consultation.

Assessing Fetal Position: Leopold's Maneuver

• Definition: Leopold's maneuver is a systematic palpation technique used to determine the position of the fetus in relation to the mother's spine.

• Purpose: Finding the baby's position is the first step in monitoring, as placing sensors over areas where the baby is kicking or punching will result in interference rather than a clear fetal heart rate (FHR).

• Clinical Implications and Standards:     * Ideal Position: The standard requirement for a vaginal induction or delivery is that the baby's position must be cephalic (head down).     * Abnormal Presentations: If the fetus is in a transverse (horizontal) or breech (feet or buttocks down) position, the provider must be notified immediately. In standard U.S. clinical practice, these presentations generally necessitate a Cesarean section (C-section) as most providers are not trained or comfortable with breech deliveries.     * Version Procedures: While procedures exist to attempt to turn a baby into a head-down position, they are only successful in perfect-case scenarios; often, if a baby is in an abnormal position, surgical intervention is the safest route.

External and Internal Monitoring Equipment

• TOCO (Tocodynamometer):     * Function: A pressure-sensitive external monitor used to detect uterine contractions.     * Placement: It is placed at the top of the uterus (the fundus) because contractions always originate from the top and move downward.     * Limitations: The TOCO can only measure the frequency and duration of contractions. It cannot measure the absolute intensity or strength of a contraction. Use of the TOCO is highly positional; its accuracy depends on maternal position (e.g., lying on the side may decrease the reading's clarity) and maternal tissue density (thicker tissue may result in smaller-looking contractions, while less tissue may result in exaggerated-looking ones).

• SONO (Ultrasound Transducer):     * Function: Detects the fetal heartbeat.     * Placement: Positioned lower on the maternal abdomen, specifically in the pelvic area where the fetal heart is most likely situated (assuming cephalic position).     * Requirements: Ultrasound gel must be used to ensure an accurate reading.

• Internal Monitors:     * Requirement: These can only be used if the patient's ‘water has broken’ (rupture of membranes), as there must be a direct path to the uterus.     * Advantage: Internal monitoring is the only way to accurately measure the strength (intensity) of contractions.

Reading and Interpreting Fetal Heart Tracings

• Visual Display Standard: The display is split into two primary sections:     * Top Section: Displays the Fetal Heart Rate (FHR).     * Bottom Section: Displays the uterine contractions.     * Secondary Line: Often includes a line for the maternal heart rate to differentiate it from the FHR.

• Grid Scaling and Timing:     * Smallest Squares: Each tiny square represents $10$ seconds.     * Bold Verticle Lines: The distance between two bold red lines represents exactly $1$ minute.     * Clinical Tip: A nurse can quickly estimate duration by counting these blocks during strip charting.

Contraction Frequency, Duration, and Uterine Activity

• Ideal Labor Pattern: The goal for an induction or active labor is $5$ contractions within a $10$-minute window (approximately one contraction every $2$ minutes).

• Tachysystole: This is defined as excessive uterine activity characterized by:     * More than $5$ contractions in a $10$-minute period.     * Contractions lasting longer than $120$ seconds.

• Risks of Tachysystole: During a contraction (specifically at its peak), the oxygen supply to the fetus is essentially restricted. Lack of sufficient rest time between contractions prevents the baby from ‘taking a breath,’ leading to fetal stress and heart rate decompensation.

• Intervention: If tachysystole occurs, the provider may administer a fluid bolus or medications to slow down or stop contractions to allow the fetus to recover.

Fetal Heart Rate Baseline and Variability

• Step 1: Determine Baseline:     * Requirement: A minimum of $10$ minutes of fetal heart rate data is required to establish a baseline. Less than that is simply a ‘heart tone.’     * Normal Range: Between $110$ and $160\,\text{bpm}$.     * Tachycardia: FHR over $160\,\text{bpm}$.     * Bradycardia: FHR under $110\,\text{bpm}$.     * Baseline Selection Method: Clinicians often use the ‘paper technique’—placing a horizontal piece of paper over the tracing to see the number hit most frequently.

• Step 2: Determine Variability: This refers to the fluctuations in the FHR baseline.     * Absent: $0\,\text{bpm}$ change (flatline/asystole). This is a critical concern.     * Minimal: Changes of $0$ to $5\,\text{bpm}$. Suggests possible low oxygenation or maternal medication effects.     * Moderate (Ideal): Changes between $6$ and $25\,\text{bpm}$. This is the standard for a healthy, well-oxygenated fetus.     * Marked: Changes greater than $25\,\text{bpm}$. May indicate acute cardiac or neurological issues; requires immediate provider notification.

Accelerations and Decelerations (VEAL CHOP)

• Step 3: Accelerations (Accels): Transient increases in FHR above baseline indicating fetal well-being.     * > 32 Weeks Gestation: Must increase by at least $15\,\text{bpm}$ and last for at least $15$ seconds ($15 \times 15$).     * < 32 Weeks Gestation: Must increase by at least $10\,\text{bpm}$ and last for at least $10$ seconds ($10 \times 10$).     * Reactive Status: At least two accelerations within a $20$-minute window.

• Step 4: Decelerations (Decels): Decreases in FHR below baseline.     * Variable Decelerations: Described as an abrupt decrease and abrupt return to baseline, often shaped like a ‘V’ or ‘W.’ Criteria: at least $15\,\text{bpm}$ below baseline for at least $15$ seconds. Correlates to Cord Compression. Intervention: Change maternal position.     * Early Decelerations: Gradual decrease that mirrors the peak of the contraction. Correlates to Head Compression. Usually not a concern as it indicates the baby is moving lower for delivery.     * Late Decelerations: Gradual decrease that occurs after the peak of the contraction. Correlates to Placental Insufficiency (perfusion issues). Requires intrauterine resuscitation.     * Prolonged Deceleration: A decrease in FHR lasting at least $2$ minutes. This is an emergency situation indicating a severe cutoff of oxygenation, often requiring immediate preparation for the Operating Room (OR).

Categorization of Fetal Heart Rate Patterns

• Category I (Normal/Green):     * FHR in range ($110$ to $160\,\text{bpm}$).     * Moderate variability ($6$ to $25\,\text{bpm}$).     * Absence of late or variable decelerations.     * Accelerations may or may not be present.

• Category III (Abnormal/Red):     * FHR may be in range, bradycardic, or tachycardic.     * Must have absent variability.     * Accompanied by recurrent late decelerations, recurrent variable decelerations, or terminal bradycardia.

• Category II (Indeterminate/Yellow):     * Defined as any pattern that does not strictly fit Category I or Category III. This covers an infinite variety of scenarios, such as minimal variability with prolonged decelerations.

Questions & Discussion

• Question: Can you repeat the normal amount of contractions for labor?

• Response: The perfect amount for an induction or labor process is $5$ contractions in a $10$-minute period (roughly every $2$ minutes). Anything over $5$ is considered tachysystole, where we need to space them out because the baby is not getting enough rest time.

• Question: Will the test show a physical strip to read?

• Response: No, because it is difficult to format a strip on the test software. The questions will be word problems where you must interpret the description (e.g., ‘abrupt decrease’) to identify the type of tracing and necessary interventions.