Fetal Heart Monitoring - Moulton Flashcards
***2 external monitors on the external abdomen for fetal monitorint
Doppler ultrasound transducer – sound waves of heart
Pressure-sensitive tocodynanmometer – FREQUENCY of contractions (NOT strength)
How to measure STRENGTH of contractions?
Intrauterine pressure catheter (IUPC)
What is fetal scalp electrode (FSE)?
Internal way to monitor fetal EKG – screw it into baby’s skull
Fetal scalp pH less than 7.2…means what?
Baby is hypoxic (due to anaerobic metabolism, causing metabolic acidosis)
How does fetal heart rate change w/ uterine contractions?
Contraction causes myometrial vessel compression, baby gets hypoxic, increases HR
- ***Fetal monitoring strip…
- Each big vertical line?
- Upper tracing?
- Lower tracing?
1 minute
Fetal heart rate over time
Uterine pressure (contractions) over time
***Baseline (middle horizontal line) in upper fetal strip?
***Each small line above/below?
120 bpm
+/- 10 bpm
***Normal uterine contraction rate
Tachysystole?
5 or less in 10 minutes, averaged over 30 minutes
More than 5 in 10 minutes, averaged over 30 minutes
***Given an IUPC strip (Montevideo units - MVUs)…how to know if contractions are strong enough for cervical change?
Add heights of all the contraction peaks together - over the course of every 10 minutes
Must be > 200 for at least 2 hrs
***Normal range of fetal heart rate
110 - 160
NORMAL (moderate) variability in fetal heart rate baseline
Measured how?
+/- 6-25 from that baby’s normal
Peak to trough as it fluctuates
***What are the possible changes in fetal heart rate over time? (including sub-categories)
- No change
- Acceleration
- Prolonged = >2 min
- Baseline ∆ = > 10 min
- Deceleration
- Early, variable, late
- Prolonged
***Types of FHR decelerations (3) - explain each
Early (mirrors contractions – from head compression - high ICP) - GOOD
Variable (abrupt, random, due to cord compression) - 15+ for 15+ minutes for under 2 min - from umbilical vein compression
Late (after peak of contraction – due to uteroplacental insufficiency – BAD if repetitive – means acidosis)
Sinusoidal pattern of FHR - means what?
Severe fetal anemia - BAD
***Recurrent variable decelerations – defined as what?
***Should do what? How? Why?
Variable decel’s in >50% of contractions
Amnioinfusion through the IUPC – to avoid acidemia
FHR strip shows reduced variability but no decelerations. What quick test can you do to test for acidemia?
Differentiates between what 2 fetal states?
Fetal scalp stimulation – will see acceleration (reactive) if pH is >7.2
Acidemia vs. sleep
***Pregnant woman in labor is doing well. All of a sudden gets spontaneous rupture of membranes. FHTs go from 120s to 50s with no variability. Not fully dilated. What is happening?
Do what? (4)
If normal fixes don’t work, do what? How long does this take?
Cord compression
Stop any oxytocin, roll on L side, oxygen, check cervix
Emergent C-section - 30 min
Pregnant woman in labor is doing well. All of a sudden gets spontaneous rupture of membranes. FHTs go down to 50s. Fully dilated…
Best way to deliver if possible?
Forceps
Quickest
MOST babies that are showing non-reassuring FHR patterns are born (healthy/poor)
HEALTHY
**Degrees of vaginal laceration
1st - vaginal mucosa
2nd - w/ some other perineum
3rd - anal sphincter
4th - rectal mucosa
Category 1 FHR
Normal baseline w/ normal variability, no late or variable decels
Category 3 FHR
Recurrent variable or late decels, no variability, sinusoidal pattern, bradycardia
Category 2 FHR
Normal baseline, some variable decels
