Lecture 13: Fetal Heart Monitoring Flashcards
What is the pressure sensitive tocodynanmometer transducer useful for measuring?
Measures frequency of contractons; but NOT the strength
Using a fetal scalp electrode for internal monitoring should be avoided in which patients?
HIV patients
Internal electronic fetal monitoring requires what?
The membranes to be ruptured
What is the pH of fetal scalp blood that is considered abnormal (fetal acidosis)?
pH <7.20
What is considered normal vs. tachysystole for uterine contractions when monitoring?
- Normal = 5 contractions or less in 10 minutes, averaged over 30 mins
- Tachysystole = >5 contractions in 10 minutes, averaged over 30 mins
How do you measure Montevideo units; what do they indicate; what is normal?
- Measure the strength of contractions in a 10 minute period (summed together)
- >200 MVU’s is adequate
What is your evaluation of the uterus based on this strip?
Tachysystole
When monitoring FHR, at what point on the strip do you assess?
Between contractions
What is a normal FHR, tachycardia, and bradycardia?
- Normal = 110-160 bpm
- Tachy = >160 bpm
- Brady = <110 bpm
Which FHR is an early sign and which is a late sign of fetal hypoxia?
- Tachycardia is an early sign of hypoxia
- Bradycardia is a late sign of hypoxia
What is the most common cause of fetal tachycardia?
Fetal infections –> Chorioamnionitis
What is the normal amount of variability in amplitude with FHR?
Moderate (normal) = range of 6-25 bpm
What is decreased baseline variability of the FHR an indicator of and when is it an ominous sign?
- Sign of fetal stress, is assoc. w/ hypoxia and acidemia
- Is ominous sign with persistent late decelerations
What is considered an acceleration of FHR at ≥ 32 weeks and at <32 weeks gestation?
- ≥ 32 weeks: HR ≥ 15 bpm above baseline for 15 sec or more (but <2 mins)
- <32 weeks: HR ≥ 10 bpm above baselines for 10 sec or more (but <2 mins)
What is considered a prolonged acceleration of FHR and how long is considered a change in baseline?
- Prolonged acceleration = ≥ 2 mins
- Change in baseline = ≥ 10 mins