Fetal Assessment during Labor

Because labor is a period of physiologic stress for the fetus, frequent monitoring of fetal status is part of nursing care during labor. The fetal oxygen supply must be maintained during labor to prevent fetal compromise and promote newborn health after birth

Which type of monitoring is NONINVASIVE

External Monitoring

Which type of monitoring is INVASIVE

Internal monitoring

Purpose of external monitoring

To assess the adequacy of fetal oxygenation during labor

Types of external monitoring

• Ultrasound transducer

• Toco transudcer

• Wireless external monitoring

What is a ultrasound transducer and what is its purpose?

High frequency sound waves that reflect the mechanical action of the fetal heart

Toco transducer

Monitors the frequency and durations of contractions through a pressure-sensing device applied to the maternal abdomen

Wireless External Monitoring

• Wireless & beltless device used w/ existing monitors to obtain fetal heart rate via abdominal ECG

Types of internal monitoring

• Fetal scalp Electrode (FSE)

• Intrauterine pressure catheter (IUPC)

What is a fetal scalp electrode and what is its purpose?

OR spiral electrode – fine spiral wire applied to the fetal scalp. It is a direct ECG of the fetal heart and is most reliable.

What is a intrauterine pressure catheter (IUPC) and what is its purpose?

Monitors

• frequency

• Duration

• Intensity of contractions by use of a catheter.

Fetal tachycardia baseline

Greater than 160 beats/min lasting for 10 mins

What are the possible causes of fetal tachycardia?

• Interruption of fetal oxygenation; results in metabolic acidemia

• Fetal cardiac arrhythmias

• Maternal Fever

• Infection (incl. chorioaminiotis)

• Parasympatholytic drugs (atropine, hydroxyzine)

• Beta-sympatomimetic drugs

• Maternal hyperthyroidism

• Fetal anemia

• drugs (caffeine, cocaine, methamphetamines)

Fetal tachycardia’s clinical significance

It poorly predicts fetal hypoxemia/acidemia.

• Can also predict this when theres absent/minimal baseline variavbility, recurrent decelerations, or both

Fetal tachycardia nursing interventions

Reduce maternal fever w/ antipyretics & cooling measures

Bradycardia fetal heart rate baseline

Less than 110 beats/min for 10 min

Fetal bradycardia

• Atrioventricular dissociation

• Structural defects

• Viral infections (cytomegalovirus)

• Medications

• Fetal heart failure

• Maternal hypoclygemia

• maternal hypothermia

• Interruption of fetal oxygenation

What is the definition of the baseline fetal heart rate?

Fetus average heart rate during a 10-minute period, rounded to increments of 5 beats/min

Definition of fetal heart rate variability

Baseline FHR irregular waves/fluctuations of 2 cycles per minute or greater (beat to beat)

• Variability can be absent, minimal, moderate, or marked

Definition of accelerations

• Visual increases or peaks in basewline FHR lasting <2 min.

• The peak mUST be 15 beats/min or more & must last at least 15 seconds from onset to return to baseline

What are the causes of accelerations?

• Spontaneous fetal movement

• Vaginal examination

• Electrode application

• Fetal scalp stimulation

• fetal reaction to external sounds

• Breech presentation

• Occiput posterior position

• Fundal pressure

• Abdominal palpation

What is the clinical significance of accelerations?

It indicates interruption of fetal oxygenation, which then leads to fetal metabolic acidemia IS NOT OCCURING at the time observed

• No interventions required

Decelerations (decel) definition

Decreases in the fetal heart rate below the baseline

• Can be early, late, variable, or prolonged

What do early decelerations indicate?

Head compression

• Not hypoxemic; benign

What are the causes of early deceleration?

By head compression RESULTING FROM

• Uterine contractions

• Vaginal examination

• Fundal pressure

• Placement of internal node of monitoring

What do variable decelerations indicate?

Umbilical cords compression

What are the specific causes of variable compression?

Umbilical cord compression caused by

• Maternal position w/ cord between fetus and maternal pelvis

• Cord around fetal neck, arm, leg, or other body part

• Short cord

• Knot in cord

• Prolapsed cord

What are the nursing internvetions of variable decelerations from first priority?

• DISCONTINUE Oxytocin if infusing

• Change maternal position (side to side, knee to chest)
  Notify obstetric HCP

• Assist w/ vaginal or speculum examination to assess for cord prolapse

• Assist w/ amnioinfusion if ordered

• Assist w/ birth (vaginal-assisted or cesarean) if pattern cannot be corrected.

What do late decelerations indicate/ what is it?

• Gradual (onset to lowest point>30 seconds) decrease in and return to baseline FHR

• Reflects the fetal response to uteroplacental insufficiency

• When they occur w/ absent or minimal baseline variability, abnormal baseline rate, and no accelerations, this can indicate FETAL metabolic acidemia.

What are the causes of late decelerations

Disruption of oxygen transfer from environment to fetus, which results in transient fetal hypoxemia, leading to late decelerations caused by

• Uterine tachysystole

• Maternal supine hypotension

• Epidural or spinal anesthesia

• Placenta previa

• Placental abruption

• Hypertensive disorders

• Post-term gestation

• Intrauterine growth restriction

• Diabetes mellitus

• Chorioamniotis

What are the nursing interventions for late decelerations?

• Discontinue oxytocin if infusing

• Assist woman to lateral (side-lying) position

• Correct maternal hypotension by elevating the legs

• Increase rate of maintenance IV solution

• Palpate uterus to assess for tachysystole

• Notify obstetric HCP

• Consider internal monitoring for more accurate fetal & uterine assessment

• Assist w/ birth (vaginal-assisted or cesarean) if pattern cannot be corrected