Chapter 15 - Fetal Assessment During Labor

Mississippi College; NUR390: Maternal, Newborn, and Women's Health; 2nd Semester

what is electronic fetal monitoring?

tool for visualizing fetal heart rate patterns on a monitor screen or printed tracing

when was fetal monitoring first used?

1970s

what was the anticipated effect for fetal monitoring?

a decrease in cerebral palsy, however, the rate has not ben declined

what is the primary mode of intrapartum assessment in the United States?

fetal monitoring

what is a period of physiologic stress for fetus?

labor

what is part of nursing care during labor?

frequent monitoring of fetal status

what must be maintained during labor to prevent fetal compromise?

fetal oxygen supply

fetal oxygen supply can decrease due to what 4 factors?

• reduction of blood flow through maternal vessels as a result of hypertension and hypotension

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

• alterations in fetal circulation with compression of umbilical cord

• reduction in blood flow to intervillous space in placenta (maternal hypertension/diabetes mellitus)

what is uterine activity?

fetal well-being during labor measured by response of FHR to uterine contractions

what is the goal of intrapartum FHR monitoring?

to identify non-reassuring patterns indicative of fetal compromise 

what are non-reassuring FHR patterns associated with?

fetal hypoxemia which if left uncorrected can progress to fetal hypoxia

what is intermittent auscultation?

listening to fetal heart sounds at periodic intervals to assess FHR

what tools can we use for intermittent auscultation?

• DeLee-Hillis fetoscope 

• Pinard stethoscope 

• Doppler ultrasound device 

what are some electronic fetal monitoring techniques?

• external monitoring

• internal monitoring (invasive)

• display

what tools can we use for external monitoring?

• FHR - ultrasound transducer

• UC - tocotransducer

what are some tools we can use for internal monitoring?

• spiral electrode 

• Montevideo units 

what are Leopold maneuvers?

palpating the maternal abdomen to identify fetal presentation an position

what positions of the fetus do we not want to see?

mentum, brow presentation, transverse 

what positions of the fetus do we want to see?

occiput

what is the most common fetus presentation do we want to see?

what is the normal range for fetal heart rate?

110-160 bpm

Know this! will have a question on test where you have to place in the right spot

baseline fetal heart rate is averaged during a __________ segment?

10 minute 

*excluding periodic changes, episodic changes, periods of marked variability, segments of the baseline that differ by more than 25 bpm

what is variability?

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

what is absent variability?

not detected with unaided eye

what is minimal variability?

detectable but less than 5 bpm

what is moderate variability?

normal (indicator of normal fetal acid-base balance)

what is marked variability?

unclear significance

what is a sinusoidal pattern variability?

regular smooth, undulating, wavelike patterns (associated with fetal anemia)

on the monitor display, FHR is displayed in the _____ section and UA is displayed in the _____ section

• upper 

• lower 

each small square on the monitor paper or screen represents how many seconds?

10 seconds

each larger box of six squares equals how many minutes?

1 minute

what are the four types of variability?

1. absent

2. minimal 

3. moderate

4. marked 

which variability do we want to see?

moderate variability

what is fetal tachycardia?

baseline more than 160 beats/min for a duration of 10 minutes or longer

what are some causes of fetal tachycardia?

• maternal/fetal infection 

• maternal hyperthyroidism 

• fetal anemia 

• in response to medications such as atropine, hydroxyzine (Vistaril), terbutaline (Brethine), and/or illicit drugs such as cocaine or methamphetamines 

• abnormalities involving fetal cardiac pacemakers and/or cardiac conduction system 

• early signs of fetal hypoxemia especially when associated with late decelerations and minimal or absent variability

what is fetal bradycardia?

baseline less than 110 beats/min for duration of 10 minutes or longer 

what are some causes of fetal bradycardia?

• fetal cardiac issues/structural defects

• maternal hypoglycemia

• maternal hypothermia

• viruses (like cytomegalovirus)

• do not get true bradycardia mixed up with prolonged decelerations

when do periodic changes in baseline FHR occur?

with contractions

are episodic changes in baseline FHR associated with contractions?

no 

what are accelerations?

• visually apparent, abrupt (onset to peak <30 seconds) increase (15 bpm) in FHR above baseline

• acceleration with fetal movement signifies fetal well-being representing fetal alertness or arousal states

• the peak is at least 15 beats/min above the baseline, and the acceleration lasts 15 seconds or more, with the return baseline less than 2 minutes from the beginning of the acceleration

decelerations can be either said as _____ or _____?

benign or abnormal

what are the four categories of decelerations?

1. early

2. late 

3. variable

4. prolonged 

what are early decelerations?

response to fetal head compression

are early decelerations “good” or “bad”?

good! usually benign and is a “mirror image” of a contraction 

what are late decelerations?

gradual decrease in and return to baseline FHR associated with UC

what are late decelerations caused by?

uteroplacental insufficiency (disruption of O2 transfer)

when does late decelerations occur?

begins after contraction

when does the lowest point of deceleration occur?

after peak of contraction 

when does baseline FHR return after a deceleration?

after contraction is over 

what are some nursing interventions for late decelerations?

• drug of choice = oxytocin

• assist woman to side-lying position

• administer oxygen at 10 L/min (nonrebreather mask)

• correct hypotension (elevate legs)

• increase rate of maintenance IV fluid

• palpate uterus for tachysystole

• notify HCP

• may need internal monitoring

• assist with birth if pattern cannot be corrected

what are variable decelerations caused by?

compression of the cord and vessels within with or without contractions

what are some specific examples of cord compression?

• maternal position with cord between fetus and maternal pelvis 

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

• short cord

• knot in cord

• prolapsed cord

variable decelerations’ decrease is at least _____ beats/min or more below the baseline, lasts at least _____ seconds, and returns to baseline in less than _____ minutes from the time of onset.

• 15

• 15

• 2

what are some nursing interventions for variable decelerations?

• discontinue oxytocin if infusing

• change maternal position (side to side, knee-chest on all fours)

• notify physician or nurse-midwife

• assist with vaginal or speculum examination to assess for cord prolapse

• assist with amnioinfusion if ordered

• assist with birth (vaginal assisted or cesarean) if pattern cannot be corrected

what are prolonged decelerations caused by?

an interruption to fetal oxygen supply

what are some things that can occur that lead to the fetus not receiving oxygen?

• maternal apnea during an eclamptic seizure 

• cord compression, stretch, or prolapse 

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

• 15

• 2

• 10

a deceleration lasting more than _____ minutes is considered a baseline change

10

what are the five essential components of the FHR tracing that must be evaluated regularly?

1. baseline rate 

2. baseline variability 

3. accelerations 

4. decelerations 

5. changes/trends over time 

Category I, II, or III FHR tracings are abnormal. Immediate evaluation and prompt intervention are required when these patterns are identified

category III

what are some nursing considerations for abnormal fetal monitoring patterns?

• begin intrauterine resuscitation

• assist client to side-lying position

• increase maternal blood volume by increasing the rate of the primary IV infusion

what are some other FHR monitoring methods of assessment techniques?

• fetal scalp stimulation 

• vibroacoustic stimulation

• umbilical cord acid-base determination 

• fetal scalp blood sampling 

what does fetal scalp stimulation (digital pressure on scalp) increase?

heart rate

what does vibroacoustic stimulation (device on maternal abdomen over fetal head) increase?

heart rate

what does umbilical cord acid-base determine?

obtained from cord/vein when FHR tracings have been abnormal 

how is fetal scalp blood sampling done?

• performed after ROM through dilated cervix

• not common practice in the US anymore

what is amnioinfusion?

infusion or room-temperature isotonic fluid (NS or LR) in the uterine cavity for low amniotic fluid

what does amnioinfusion relieve?

intermittent umbilical cord compression 

how do we perform amnioinfusion?

• through gravity or a pump

• less than 1000 mL infused by bolus over 20-30 minutes

• monitor for distension/uterine resting tone

what is tocolytic therapy?

• tocolysis causes relaxation of the uterus (slows or stops contractions)

• improves oxygenation to the fetus

what is the most common tocolytic drug?

Terbutaline (Brethine)

what are some common adverse effects of tocolytic therapy?

• palpitations

• chest pain

• rapid heart rise

• tremor

• nervousness

what are some patient and family teaching points for amnioinfusion and tocolytic therapy?

• explain purpose and procedure

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

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

what are some things you want to document for amnioinfusion and tocolytic therapy?

• clear and complete documentation in the woman’s medical record is essential 

• each FHR and UA assessment must be documented completely 

Use this to help :)

fetal tachycardia is most common during which of the following situations/conditions?

A. maternal fever

B. umbilical cord prolapse

C. regional anesthesia

D. MgSO4 administration

A. maternal fever