Fetal Heart Sounds

Question 1

3 reasons that support the use of FHM?

Answer 1

Reassurance, greater than 98% that good fetal outcome is associated with FHM
Too expensive for 1:1 auscultation
The monitoring can be a warning of problems and gauge fetal responses as well

Question 2

What is normal fetal oxygen reserve? What happens during uterine contraction that has an effect on placental exchange?

Answer 2

1-2 minutes of reserve

Exchange through the placenta is interrupted during uterine contraction.

Question 3

What do the upper and lower tracings monitor in the fetal strip?

Answer 3

Upper is fetal HR

Lower is uterine contraction

Question 4

What is considered normal uterine contraction activity and what is considered tachsystole?

Answer 4

5 contractions or less in 10 minutes averaged over 30 minute period
Greater than 5 contractions in 10 minutes averaged over 30 minute period

Question 5

What is normal Intra uterine pressure or better, what does it need to be to progress to labor? How are we measuring it?

Answer 5

Over 200 in a ten minute period. IUPC.

Summing up the pressures of contractions in a ten minute period. Do this for 2 hours.

Question 6

What is normal, tachycardia, and bradycardia for fetal HR?

Answer 6

110-160
Greater than 160
Less than 110

Question 7

How do we get a baseline FHR?

Answer 7

Average rounded to increments of 5bpm over ten minute period in between contractions

Question 8

6 causes of bradycardia in baby?

Answer 8

Hypoxia, late
Anesthesia
Mother is hypotensive
Compression of umbilical cord
Pitocin
Heart block

Question 9

6 causes of tachycardia and which one is most common?

Answer 9

Early phase of hypoxia
Too much pitocin
Arrhythmias
Prematurity
Maternal fever
Infection most common

Question 10

How do we define baseline variability, what are the 4 types and how do we define the types?

Answer 10

Distance of peak and trough from baseline. 
Absent - nothing
Minimal - less than 5 bpm
Moderate - 6-25
Marked - greater than 25

Question 11

Decreased variability is associated with what?

Answer 11

Hypoxia and acidosis causing CNS and HR depression

Question 12

6 causes of decreased variability

Answer 12

Prematurity, mom has fever, tachycardia, congenital anomalies, mom is hyperthyroid, and mom doing drugs.

Question 13

Explain normal fetal HR accelerations and when they occur?

Answer 13

Greater than 32 weeks, 15 above baseline for 15 seconds

Less than 32 weeks, 10 above baseline for 10 seconds

Question 14

What is considered prolonged acceleration and when do we see we have a change in baseline?

Answer 14

Acceleration greater than 2 minutes

Greater than 10 minutes

Question 15

3 causes of accelerations?

Answer 15

Spontaneous fetal movement
Scalp or vibroacoustic stimulation
Vaginal exam

Question 16

What is the cause of early decelerations and what do we see on the fetal strip?

Answer 16

Fetal head compression

The trough mirrors the contraction

Question 17

What is the cause of variable deceleration, what will we see on the fetal strip and what is acceptable for the time the FHR is depressed?

Answer 17

Compression of umbilical cord.
Can decrease before, during or after contraction
Can decrease greater than 15 bpm, for 15 seconds, but less than 2 minutes.

Question 18

What is going in physiologically and on the fetal strip during the phenomenon they call shoulder?

Answer 18

Umbilical vein is compressed which carries the oxygenated blood to baby heart. This will be a slight increases in HR followed by a major drop.

Question 19

What is the cause of late decelerations and what do repetitive late decelerations means?

Answer 19

Uterine placental insufficiency, either by maternal hypotension or excessive uterine activity.
Baby is hypoxic and acidosis

Question 20

What is the cause of prolonged deceleration and what does the fetal strip show?

Answer 20

Disruption of oxygen transfer to fetus, commonly seen during maternal pushing.
Greater than 15 bpm decrease over 2 minutes.

Question 21

What does the fetal strip show for fetal anemia?

Answer 21

Sinusoidal

Question 22

Let’s say tracing shows recurrent variable decelerations with greater than 50 % of contractions, what is the problem and what 3 things to treat?

Answer 22

Umbilical cord compression

Reposition, Modify how mom is pushing, amnioinfusion

Question 23

What is amnioinfusion?

Answer 23

Infusion of normal saline can alleviate cord compression

Question 24

What is the goal to treat tachysystole in baby?

Answer 24

Reduce uterine activity

Question 25

How do we manage sinusoidal pattern?

Answer 25

Prepare for delivery

Question 26

Explain the importance of the fetal scalp stimulation?

Answer 26

If an acceleration of 15 bpm lasting 15 seconds occurs, the fetal pH is almost always greater than 7.22 which can help us differentiate between sleep and acidosis

Question 27

Category 3 is absent of variability and has any of the following 3 tracings? Category 3 can also be what tracing alone? What is the goal of management?

Answer 27

Recurrent late dec, recurrent var dec, bradycardia.
Sinusoidal
Prepare to deliver

Question 28

What is the goal of category 2?

Answer 28

Get oxygen to baby’s

Question 29

Electronic fetal monitoring does not results in reduction of what disease?

Answer 29

Cerebral palsy