A. Description

1. The fetal monitor displays the fetal heart rate (FHR).

2. The device monitors uterine activity.

3. The monitor assesses frequency, duration, and intensity of contractions.

4. The monitor assesses FHR in relation to maternal contractions.

5. Baseline FHR is measured between contractions; the normal FHR at term is 110 to 160 beats/minute.

1. External fetal monitoring is noninvasive and is performed with a tocotransducer or Doppler ultrasonic transducer.

2. Leopold’s maneuvers are performed to determine on which side the fetal back is located, and the ultrasound transducer is placed over this area (fasten with a belt or stocking tubing).

3. The tocotransducer is placed over the fundus of the uterus, where contractions feel the strongest (fasten with a belt or stocking tubing).

4. The client is allowed to assume a comfortable position, avoiding vena cava compression (maternal supine hypotensive syndrome).

5. The preferred position is to have the client lie on her side to increase perfusion.

Fetal Heart Rate

Ultrasound transducer:

High-frequency sound waves reflect mechanical action of fetal heart; noninvasive; does not require rupture of membranes or cervical dilation; used during both antepartum and intrapartum periods

Uterine Activity

Tocotransducer:

Monitors frequency and duration of contractions by means of pressure-sensing device applied to maternal abdomen; used during both antepartum and intrapartum periods.

1. Internal fetal monitoring is invasive and requires rupturing of the membranes and attaching an electrode to the presenting part of the fetus.

2. The client must be dilated 2 to 3 cm to perform internal monitoring.

Fetal Heart Rate

Spiral electrode:

Converts fetal ECG as obtained from presenting part to FHR via cardiotachometer; can be used only when membranes are ruptured and cervix is sufficiently dilated during intrapartum period; electrode penetrates into fetal presenting part by 1.5 mm and must be attached securely to ensure good signal

Uterine Activity

Intrauterine pressure catheter (IUPC):

Monitors frequency, duration, and intensity of contractions; two types of IUPCs: fluid-filled system and solid catheter; both measure intrauterine pressure at catheter tip and convert pressure into millimeters of mercury on uterine activity panel of strip chart; both can be used only when membranes are ruptured and cervix is sufficiently dilated during intrapartum period

FHR is less than 110 beats/minute for 10 minutes or longer.

Most commonly occurs due to prolonged umbilical cord compression

True bradycardia occurs rarely and is not specifically related to fetal oxygenation.

Fetal bradycardia can be considered a later sign of fetal hypoxia and is known to occur before fetal death. Bradycardia can result from placental transfer of drugs, prolonged compression of the umbilical cord, maternal hypothermia, and maternal hypotension. 

Baseline bradycardia alone is not specifically related to fetal oxygenation. Clinical significance of bradycardia depends on underlying cause and accompanying FHR patterns, including variability, accelerations, or decelerations.

FHR is more than 160 beats/minute for 10 minutes or longer.

Considered early sign of fetal hypoxemia, especially when associated with late decelerations and minimal or absent variability.

Clinical Significance

Persistent tachycardia in absence of periodic changes does not appear serious in terms of neonatal outcome (especially true if tachycardia is associated with maternal fever); tachycardia is abnormal when associated with late decelerations, severe variable decelerations, or absent variability.

Nursing Interventions

Dependent on cause; reduce maternal fever with antipyretics as ordered and cooling measures; oxygen at 10 L/min by nonrebreather face mask may be of some value; carry out health care provider’s orders based on alleviating cause

Variability of the FHR can be described as irregular waves or fluctuations in the baseline FHR of two cycles per minute or greater.

Variability is quantified in beats per minute and is measured from the peak to the trough of a single cycle.

Absent Variability: Undetected variability

Minimal Variability: Greater than undetected but not more than 5 beats/minute

Moderate Variability: Fetal heart rate fluctuations are 6 to 25 beats/minute. Considered Normal.

Marked Variability: Fetal heart rate fluctuations are greater than 25 beats/minute

Sinusoidal Pattern: Regular smooth, undulating wavelike pattern. Occurs with fetal anemia, chorioamnionitis, fetal sepsis and administration of narcotic analgesics.

a. Fluctuations in baseline FHR

b. Absent or undetected variability is considered nonreassuring.

c. Decreased variability can result from fetal hypoxemia, acidosis, or certain medications.

d. A temporary decrease in variability can occur when the fetus is in a sleep state (sleep states do not usually last longer than 30 minutes).

e. Absent or minimal variability can result from fetal hypoxemia or metabolic acidemia.

f. CNS depressant medications, including analgesics, narcotics (meperidine [Demerol]), barbiturates (secobarbital [Seconal] and pentobarbital [Nembutal]), tranquilizers (diazepam [Valium]), phenothiazines (promethazine [Phenergan]), and general anesthetics are other possible causes of minimal variability.

a. Brief, temporary increases in FHR of at least 15 beats/minute more than baseline and lasting at least 15 seconds or more, with the return to baseline less than 2 minutes from the beginning of the acceleration.

b. Usually are a reassuring sign, reflecting a responsive, nonacidotic fetus

c. Usually, occur with fetal movement

d. Maybe nonperiodic (having no relation to contractions) or periodic (with contractions)

e. May occur with uterine contractions, vaginal examinations, or mild cord compression, or when the fetus is in a breech presentation.

f. Accelerations can be either periodic or episodic

a. Early decelerations are decreases in FHR below baseline; the rate at the lowest point of the deceleration usually remains greater than 100 beats/minute. Onset to lowest point ≥30 seconds.

b. Early decelerations occur during contractions as the fetal head is pressed against the mother’s pelvis or soft tissues, such as the cervix, and return to baseline FHR by the end of the contraction; causing altered fetal cerebral blood flow.

c. Tracing shows a uniform shape and mirror image of uterine contractions.

d. Early decelerations are not associated with fetal compromise and require no intervention.

a. Late decelerations are nonreassuring patterns that reflect impaired placental exchange or uteroplacental insufficiency. (onset to lowest point ≥30 seconds)

b. The patterns look similar to early decelerations, but begin well after the contraction begins and return to baseline after the contraction ends.

c. The degree of decline in FHR from baseline is not related to the amount of uteroplacental insufficiency.

d. Late decelerations may be caused by maternal supine hypotension syndrome. 

These factors include maternal hypotension, uterine tachysystole (e.g., more than five contractions in 10 minutes averaged over a 30-minute window), preeclampsia, postdate or postterm pregnancy, amnionitis, small-for-gestational-age fetuses, maternal diabetes, placenta previa, placental abruption, conduction anesthetics, maternal cardiac disease, and maternal anemia. Rarely fetal oxygenation can be interrupted sufficiently to result in metabolic acidemia.

For that reason late decelerations should be considered an ominous sign when they are associated with absent or minimal variability. The most common cause of late decelerations is uterine tachysystole, usually caused by oxytocin (Pitocin) administration.

Variable decelerations

a. Variable decelerations are caused by conditions that restrict flow through the umbilical cord caused like umbilical cord compression.

b. Variable decelerations do not have the uniform appearance of early and late decelerations.

c. The shape, duration, and degree of decline below baseline FHR are variable; these fall and rise abruptly with the onset and relief of cord compression.

d. Variable decelerations also may be nonperiodic, occurring at times unrelated to contractions.

e. Baseline rate and variability are considered when evaluating variable decelerations.

f. Variable decelerations are significant when FHR repeatedly declines to less than 70 beats/minute and persists at that level for at least 60 seconds before returning to baseline.

Nursing Interventions

The usual priority is as follows:

1. Change maternal position (side to side, knee chest).

2. Discontinue oxytocin if infusing.

3. Administer oxygen at 8 to 10 L/min by nonrebreather face mask.

4. Notify physician or nurse-midwife.

5. Assist with vaginal or speculum examination to assess for cord prolapse.

6. Assist with amnioinfusion if ordered.

7. Assist with birth (vaginal assisted or cesarean) if pattern cannot be corrected.

a. Assessment of uterine activity includes frequency, duration, intensity of contractions, and uterine resting tone; assessment is performed either by palpating by hand or with an internal uterine pressure catheter (IUPC).

b. The uterus should relax between contractions for 60 seconds or longer.

c. Uterine contraction intensity is about 50 to 75 mm Hg (with an IUPC) during labor and may reach 110 mm Hg with pushing during the second stage.

d. The average resting tone is 5 to 15 mm Hg.

e. In hypertonic uterine activity, the uterine resting tone between contractions is high, reducing uterine blood flow and decreasing fetal oxygen supply.

■ Bradycardia

■ Tachycardia

■ Late decelerations

■ Prolonged decelerations

■ Hypertonic uterine activity

■ Decreased or absent variability

■ Variable decelerations falling to less than 70 beats/minute for longer than 60 seconds 

1. Identify the cause.

2. Discontinue oxytocin (Pitocin) infusion.

3. Change the mother’s position.

4. Administer oxygen by face mask at 8 to 10 L/minute and infuse intravenous fluids as prescribed.

5. Prepare to initiate continuous electronic fetal monitoring with internal devices if not contraindicated.

6. Prepare for cesarean delivery if necessary.

7. Document the event, actions taken, and the mother’s response.

Nonreassuring fetal heart rate patterns include bradycardia, tachycardia, late decelerations, prolonged decelerations, hypertonic uterine activity, decreased or absent variability, or variable decelerations falling to less than 70 beats/minute for longer than 60 seconds. If a nonreassuring fetal heart rate pattern is noted, the health care provider (HCP) or nurse-midwife is notified as soon as possible (the nurse stays with the client and asks another nurse to contact the HCP). The nurse needs to identify the cause of the pattern immediately. This includes checking for a prolapsed umbilical cord and checking maternal vital signs to identify hypotension, hypertension, or fever that can contribute to the fetal response associated with the nonreassuring pattern. If the mother is receiving an oxytocin (Pitocin) infusion, it is stopped because oxytocin causes uterine stimulation, which can worsen the nonreassuring pattern. A tocolytic may be prescribed. The mother is repositioned because this may improve placental perfusion (avoid the supine position). Oxygen is administered by face mask at 8 to 10 L/minute to increase maternal blood oxygen saturation, making more oxygen available to the fetus, and intravenous fluids are infused to expand the mother’s blood volume and improve placental perfusion. If not contraindicated, the nurse prepares to initiate continuous electronic fetal monitoring with internal devices. Cesarean delivery may be necessary, and the nurse should prepare for this procedure. Birth preparation should also include neonatal resuscitation. The nurse documents the event, actions taken, the mother’s response, and any other pertinent data.

• Reduction of blood flow through the maternal vessels as a result of maternal hypertension (chronic hypertension, preeclampsia, or gestational hypertension), hypotension (caused by supine maternal position, hemorrhage, or epidural analgesia or anesthesia), or hypovolemia (caused by hemorrhage)

• Reduction of the oxygen content in the maternal blood as a result of hemorrhage or severe anemia

• Alterations in fetal circulation, occurring with compression of the umbilical cord (transient, during uterine contractions [UCs], or prolonged, resulting from cord prolapse), partial placental separation or complete abruption, or head compression (head compression causes increased intracranial pressure and vagal nerve stimulation with an accompanying decrease in the FHR)

• Reduction in blood flow to the intervillous space in the placenta secondary to uterine hypertonus (generally caused by excessive exogenous oxytocin) or secondary to deterioration of the placental vasculature associated with maternal disorders such as hypertension or diabetes mellitus

1. Palpate maternal abdomen to identify fetal presentation and position.

2. Apply ultrasonic gel to device if using Doppler ultrasound. Place listening device over area of maximal intensity and clarity of fetal heart sounds to obtain clearest and loudest sound, which is easiest to count. This location is usually over the fetal back. If using fetoscope, firm pressure may be needed.

3. Count maternal radial pulse while listening to FHR to differentiate it from fetal rate.

4. Palpate abdomen for presence or absence of uterine activity (UA) to count FHR between contractions.

5. Count FHR for 30 to 60 seconds after a uterine contraction to identify auscultated baseline rate and changes (increases or decreases) in it.

6. Auscultate FHR before, during, and after contraction to identify FHR during the contraction or as a response to the contraction and to assess for absence or presence of increases or decreases in FHR.

7. When distinct discrepancies in FHR are noted during listening periods, auscultate for longer period during, after, and between contractions to identify significant changes that may indicate need for another mode of FHR monitoring.

• Uses abdominally obtained electronic impulses to monitor both FHR and UA.
• Uses five electrodes placed on the woman's abdomen to directly monitor the electrocardiogram from the maternal and fetal hearts and the electromyogram from the uterine muscle.
• Information transmitted wirelessly via Bluetooth technology, to an interface device that allows the FHR and UA data to print or display on a standard fetal monitor.
• This system eliminates much of the problem caused by signal loss resulting from maternal or fetal movement or maternal obesity that often occurs with traditional external monitors.
• More accurately measures the frequency, occurrence of the peak, and duration of UCs.
• Does not provide actual intensity measurement in millimeters of mercury as an IUPC does.
• No abdominal belts
• eliminates frequent readjustment of the tocotransducer and ultrasound transducer and provides patient mobility

The baseline FHR is the average rate during a 10-minute segment that excludes periodic or episodic changes, periods of marked variability, and segments of the baseline that differ by more than 25 beats/min. There must be at least 2 minutes of interpretable baseline data in a 10-minute segment of tracing to determine the baseline FHR. After 10 minutes of tracing is observed, the approximate mean rate is rounded to the closest 5 beats/min interval. For example, if the FHR rate varies between 130 and 140 beats/min over a 10-minute period, the baseline is recorded as 135 beats/min. The normal range at term is 110 to 160 beats/min. In the preterm fetus the baseline rate is slightly higher.

Causes

• Spontaneous fetal movement

• Vaginal examination

• Electrode application

• Fetal scalp stimulation

• Fetal reaction to external sounds

• Breech presentation

• Occiput posterior position

• Uterine contractions

• Fundal pressure

• Abdominal palpation

Clinical Significance

• Normal pattern: Acceleration with fetal movement signifies fetal wellbeing representing fetal alertness or arousal states.

Nursing Interventions

• None required

Cause

Disruption of oxygen transfer from environment to fetus caused by the following:

• Uterine tachysystole

• Maternal supine hypotension

• Epidural or spinal anesthesia

• Placenta previa

• Placental abruption

• Hypertensive disorders

• Postmaturity

• Intrauterine growth restriction

• Diabetes mellitus

• Intraamniotic infection

Clinical Significance

Abnormal pattern associated with fetal hypoxemia, acidemia, and low Apgar scores; considered ominous if persistent and uncorrected, especially when associated with absent or minimal baseline variability

Nursing Interventions

The usual priority is as follows:

1. Change maternal position (lateral).

2. Correct maternal hypotension by elevating legs.

3. Increase rate of maintenance intravenous solution.

4. Palpate uterus to assess for tachysystole.

5. Discontinue oxytocin if infusing.

6. Administer oxygen at 8 to 10╯L/min by nonrebreather face mask.

7. Notify physician or nurse-midwife.

8. Consider internal monitoring for more accurate fetal and uterine assessment.

9. Assist with birth (cesarean or vaginal assisted) if pattern cannot be corrected.

A prolonged deceleration is a visually apparent decrease (may be either gradual or abrupt) in FHR of at least 15 beats/min below the baseline and lasting more than 2 minutes but less than 10 minutes. A deceleration lasting more than 10 minutes is considered a baseline change.

Prolonged decelerations are caused when the mechanisms responsible for late or variable decelerations last for an extended period (more than 2 minutes). Examples of conditions that can cause an interruption in the fetal oxygen supply long enough to produce a prolonged deceleration include maternal hypotension, uterine tachysystole or rupture, extreme placental insufficiency, and prolonged cord compression or prolapse.

The presence and degree of hypoxia are thought to correlate with the depth and duration of the deceleration, how abruptly it returns to the baseline, how much variability is lost during the deceleration, and whether rebound tachycardia and loss of variability occur after the deceleration.

Are baseline rate, baseline variability, accelerations,

decelerations, and changes or trends over time. Whenever one of these five essential components is assessed as abnormal, corrective measures must be taken immediately. The purpose of these actions is to improve fetal oxygenation.

Basic Interventions

• Administer oxygen by nonrebreather face mask at rate of 10 L/min for approximately 15 to 30 minutes.

• Assist woman to a side-lying (lateral) position.

• Increase maternal blood volume by increasing rate of primary IV infusion.

Interventions for Specific Problems

• Maternal hypotension

• Increase rate of primary IV infusion.

• Change to lateral or Trendelenburg positioning.

• Administer ephedrine or phenylephrine if other measures are unsuccessful in increasing blood pressure.

• Uterine tachysystole (6 contractions in a 10-minute period)

• Reduce or discontinue dose of any uterine stimulants in use (e.g., oxytocin [Pitocin]).

• Administer uterine relaxant (tocolytic) (e.g., terbutaline [Brethine]).

• Abnormal fetal heart rate pattern during the second stage of labor

• Use open-glottis pushing.

• Use fewer pushing efforts during each contraction.

• Make individual pushing efforts shorter.

• Push only with every other or every third contraction.

• Push only with perceived urge to push (in women with regional anesthesia).

intrapartum test for fetal well-being; acceleration of the fetal heart rate in response to digital or forceps stimulation of scalp is associated with a normal scalp blood pH.

The desired result of these stimulation methods is acceleration in the FHR of at least 15 beats/min for at least 15 seconds. FHR acceleration indicates the absence of metabolic acidemia.

If the fetus does not respond, fetal compromise is not necessarily indicated; however, further evaluation of fetal well-being is needed. Fetal stimulation should be performed at times when the FHR is at baseline. Neither fetal scalp nor vibroacoustic stimulation should be instituted if FHR decelerations or bradycardia is present

A test of fetal responsiveness during pregnancy. A transducer is placed on the mother's abdomen, into which the transducer emits an oscillating sound. The fetal response is measured.

The desired result of these stimulation methods is acceleration in the FHR of at least 15 beats/min for at least 15 seconds. FHR acceleration indicates the absence of metabolic acidemia.

If the fetus does not respond, fetal compromise is not necessarily indicated; however, further evaluation of fetal well-being is needed. Fetal stimulation should be performed at times when the FHR is at baseline. Neither fetal scalp nor vibroacoustic stimulation should be instituted if FHR decelerations or bradycardia is present

In assessing the immediate condition of the newborn after birth, a sample of cord blood is a useful adjunct to the Apgar score, especially if there has been an abnormal or confusing FHR tracing during labor or neonatal depression at birth. Generally the procedure is performed by withdrawing blood from both the umbilical artery and the umbilical vein. Both samples are then tested for pH, carbon dioxide pressure (Pco2), oxygen pressure (Po2), and base deficit or base excess. Umbilical arterial values reflect fetal condition, whereas umbilical vein values indicate placental function

Obtaining cord blood values in the following clinical situations: cesarean birth for fetal compromise, low 5-minute Apgar score, severe intrauterine growth restriction, abnormal FHR tracing, maternal thyroid disease, intrapartum fever, and multifetal gestation.

Artery Normal Levels: pH 7.2-7.3 PcO2 45-55 Po2 15-25 Base Deficit <12

Vein Normal Levels: pH 7.3-7.4 PcO2 35-45 Po2 25-35 Base Deficit <12

Amnioinfusion is used during labor either to dilute meconium-stained amniotic fluid or to supplement the amount of amniotic fluid to reduce the severity of variable decelerations caused by cord compression.

Amnioinfusion is infusion of room-temperature isotonic fluid (usually normal saline or lactated Ringer’s solution) into the uterine cavity if the volume of amniotic fluid is low. Without the buffer of amniotic fluid, the umbilical cord can easily become compressed during contractions or fetal movement, diminishing the flow of blood between the fetus and placenta. The purpose of amnioinfusion is to relieve intermittent umbilical cord compression that results in variable decelerations and transient fetal hypoxemia by restoring the amniotic fluid volume to a normal or near-normal level.

Women with an abnormally small amount of amniotic fluid (oligohydramnios) or no amniotic fluid (anhydramnios) are candidates for this procedure.

Risks of amnioinfusion are overdistention of the uterine cavity and increased uterine tone. Fluid is administered through an IUPC by either gravity flow or an infusion pump. Usually a bolus of fluid is administered over 20 to 30 minutes; then the infusion is slowed to a maintenance rate. Likely no more than 1000 mL of fluid will need to be administered. The fluid can be warmed for the preterm fetus by infusing it through a blood warmer.

Uterine resting tone should not exceed 40 mm Hg during the procedure.

Relaxation of the Uterus

Can be achieved by drugs that inhibit Uterian Contractions. Used for management of fetal stress when the fetus is exhibiting abnormal patterns associated with increased UA. 

Tocolysis improves blood flow through the placenta by inhibiting UC.

Drugs: Terbutaline (Brethine) SubQ- improves Apgar scores and cord pH values without apparent complications.

Once FHR and UC patterns improve, labor can continue.

The following guidelines relate to patient teaching and the functioning of the monitor.

• Explain purpose of monitoring.

• Explain each procedure.

• Provide rationale for maternal position other than supine.

• Explain that fetal status can be assessed continuously by electronic fetal monitoring (EFM), even during contractions.

• Explain that lower tracing on the monitor strip paper shows uterine activity (UA); upper tracing shows the fetal heart rate (FHR).

• Reassure woman and partner that prepared childbirth techniques can be implemented without difficulty.

• Explain that during external monitoring effleurage can be performed on sides of abdomen or upper portion of thighs.

• Explain that breathing patterns based on time and intensity of contractions can be enhanced by observing uterine activity on monitor strip, which shows the onset of contractions.

• Note peak of contraction; knowing that contraction will not get stronger and is halfway over is usually helpful.

• Note diminishing intensity.

• Coordinate with appropriate breathing and relaxation techniques.

• Reassure woman and partner that use of internal monitoring does not restrict movement, although she is confined to bed.*

• Explain that use of external monitoring usually requires woman’s cooperation during positioning and movement.

• Reassure woman and partner that use of monitoring does not imply fetal jeopardy.

• Fetal well-being during labor is gauged by the response of the FHR to UCs.

• Standardized definitions for many common FHR patterns have been adopted for use in clinical practice by the ACNM, ACOG, and AWHONN.

• The five essential components of the FHR tracing are baseline rate, baseline variability, accelerations, decelerations, and changes or trends over time.

• The monitoring of fetal well-being includes FHR and UA assessment and assessment of maternal vital signs.

• The FHR can be monitored by either IA or EFM. The FHR and UA can be assessed by EFM using either the external or internal monitoring mode.

• Assessing FHR and UA patterns, implementing independent nursing interventions, and reporting abnormal patterns to the physician or nurse-midwife are the nurse’s responsibilities.

• The AWHONN and ACOG have established and published health care provider standards and guidelines for FHR monitoring.

• The emotional, informational, and comfort needs of the woman and her family must be addressed when the mother and her fetus are being monitored.

• Documentation of fetal assessment is initiated and updated according to institutional protocol.