Fetal Heart Monitoring Lecture Powerpoint

Question 1

2 methods to monitor the fetal heart rate

Answer 1

• auscultation
• electronically (nowadays this is the most common obstetrical procedure reviewed frequently thru the first and 2nd stages of delivery)

Question 2

Methods of external fetal heart rate monitoring electronically (2)

Answer 2

• ultrasound doppler with gel held in position by belt (not as strong)
• internal FHR monitoring, a bipolar electrode attached to fetal scalp with a wire penetrating the scalp (membranes are ruptured) where a 2nd pole is the metal base of the electrode and vaginal fluid creates saline electric bridge (requires intact maternal physiology, functional placenta, and fetus)

Question 3

Insufficient o2 or nutrition (chronic, long term malnutrition) in the mother can cause these things (5)

Answer 3

• intrauterine growth restriction
• hypoxia
• metabolic acidosis
• acute aspyxia
• fetal death

Question 4

Placenta function can be chronically impaired by these things (5)

Answer 4

• hypertension
• pre-eclampsia
• type 1 diabetes
• Rh sensitization
• intrauterine growth restriction

Question 5

Placenta function can be acutely impaired by these things (3)

Answer 5

• placental separation
• placental infarct
• maternal or fetal hypotension

Question 6

Tachysystole (uterine activity)

Answer 6

More than 5 contractions in 10 min averaged over 30 minutes, should always be qualified as to the presence or absence of fetal heart rate abnormality

Question 7

Basic warning signs in labor (4)

Answer 7

• contractions lasting longer than 90 seconds (starve fetus of oxygen and nutrients)
• relaxation between contractions of less than 60 seconds (if not at rest for long enough, not enough time to wash out co2 and gain o2 and nutrients)
• resting uterine tone above 20mmhg (normal is 5-10 mmHg, during labor may be 10-15)
• peak pressure of contractions above 90 mmHg

Question 8

Normal fetal heart rate during development and at term

Answer 8

110-160bpm, until week 26 heart rate controlled by sympathetic NS, as matures parasympathetic increases in control slowing the heart to 110-120bpm

Question 9

Tachycardia of fetal heart rate

Answer 9

Greater than 160bpm

Question 10

Factors associated with fetal tachycardia (6)

Answer 10

• fetal/maternal temp elevation
• medication side effects
• acidosis
• arrhythmia
• hypovolemia
• hyperthyroidism

Question 11

Factors associated with fetal bradycardia (4)

Answer 11

• post term fetus (mature parasympathetic system)
• hypoxia
• B blockers
• damage to fetal heart

Question 12

Short term healthy variability in fetal heart rate

Answer 12

Should have amplitude ranging from 5-15 beats per minute indicates good autonomic interplay

Question 13

Short term variability in the fetal heart rate below 5bpm may indicate (4)

Answer 13

• fetal sleep period
• CNS depression
• hypoxia
• drugs or maternal smoking

Question 14

Response to decreased short term or long term variability in fetal heart rate (5)

Answer 14

• stimulate fetus
• attach scalp electrode for internal monitor
• check fetal pH
• change maternal position
• just deliver the damn thing

Question 15

Long term variability in fetal heart rate

Answer 15

Variability in the baseline rate over a more extended period of time (1 min) usually amplitude of 3-25 bpm, decreased during sleep, drugs, hypoxia, and tachycardia and increased during hypoxia

Question 16

Head compression

Answer 16

Predictable event as uterus compresses engaged head causing vagal slowing causing early decelaration of fetal heart rate and ends with same time as uterine contraction, NOT considered a sign of distress

Question 17

Uteroplacental insufficiency

Answer 17

Predictable event as uterus compresses engaged head causing vagal slowing causing LATE decelaration of fetal heart rate in comparison to uterine contraction,

Question 18

Response to uteroplacental insufficiency (late decelerations)

Answer 18

• change maternal position to side (prevent positional compression)
• stop oxytocin
• increase IV fluids
• o2 for mom up to 100%

Question 19

Cord compression

Answer 19

Predictable event as uterus comresses the umbilical cord causing VARIABLE decelerations of fetal heart rate, most common, if prolonged causes hypoxia

Question 20

Response to cord compression (variable decelerations) (4)

Answer 20

• change maternal position to right or left side
• 100% o2
• stop oxytocin
• deliver via forceps or c-section

Question 21

Category 1-3 FHR tracings

Answer 21

Category 1 - normal, strongly predictive of normal fetal acid base status at delivery
Category 2 - Tracings are indeterminate, not predictive of abnormal fetal acid base status, require eval and continued surveillance and re-eval
category 3 - tracins are abnormal, associated with abnormal fetal acid base balance, requires prompt eval, maternal o2, change in position, etc

Question 22

Category 1 FHR tracings characteristics

Answer 22

Baseline rate 110-160
Baseline variability: moderate
Late or variable decelerations: absent
Early decelerations: present or absent
Accelerations: present or absent

Question 23

Category 2 FHR tracings characteristics

Answer 23

Baseline rate: bradycardia or tachycardia without absent baseline variability
Baseline Variability: absent with no recurring decelerations, minimal, marked
Accelerations: absent or present after fetal stimulation

Question 24

Category 3 FHR tracings characteristics

Answer 24

Category 3 tracings include absent baseline FHR variability and any of the following:
Recurring late decelerations
Recurring variable decelerations
Bradycardia
Sinusoidal pattern

Question 25

Brain damage in labor determining factors (did it happen during labor and not beforehand?) (4)

Answer 25

• profound umbilical artery acidemia (pH <7)
• apgar score 0-3 for longer than 5 min
• neonatal neurological sequelae (seizures, coma, hypotonia)
• multiorgan system dysfunction

Question 26

Fetal monitoring overreliance

Answer 26

Out of 1000 fetuses with appearing fetal distress on FHR tracing only 1-2 developed cerebral palsy, in other words we are over c-sectioning due to overreliance however it is better than auscultation technique in most and makes it easier on nurses so it is here to stay