Fetal Surveillance during labor Flashcards
is external monitoring useful for measure the frequency or strength of contractions? which one?
- frequency only
- the IUPC can sense strength real well
What is the pH of the fetal scalp normally?
-7.25-7.3
what is considered fetal acidosis?
-<7.2
what does the upper tracing monitor?
-fetal heart rate
What does the lower tracing monitor?
-uterine contractions
What isthe normal uterine contraction rate?
5 contractions or less in 10 minutes averaged over a 30 minute window
-if greater, then it’s tachysystole
What do we do with the montevideo units?
-add them up over a 10 minute period
> 5 contractions in 10 min… what is it?
-tachysystole
When is baseline FHR identified?
-between uterine contractions
What is the normal baseline FHR?
-110 to 160 bpm
is fetal tachycardia early or late sing of hypoxia?
- early
- late sign is bradycardia
what are the landmark values for the FHR variability (peak to trough)?
- 6 and 25.
- minimal, moderate, and marked
what does decreased variability mean?
-fetal stress
What do we have to remember about abrupt accelerations?
-it’s a normal reassuring response
What is prolonged acceleration?
- lasts >2 minutes
What is change in baseline acceleration?
- lasts > 10 min
What are the early decelerations looking like on the graph thing?
- mirror images!!!
- uterus contracts… decrease in FHR
- fetal head compression
What is the key for Variable decelerations?
- they look like a big “V”…. they are just bigger
- secondary to umbilical cord compression
- the umbilical vein is what will get compressed, that is what returns oxygenated blood to the fetal heart
What are late decelerations caused by?
- uterine placental insufficiency (UPI)
- the decelerations happen AFTER the uterine contraction
when is prolonged deceleration commonly seen?
-with maternal pushing
What do we think of if we see a sinusoidal pattern of uterine contraction?
-fetal anemia
Describe the 3 FHR pattern categories?
- 1: normal
- 2: intermittent variable decelerations, if recurrent, think umbilical cord stuff
- 3: worst, recurrent late decels, sinusoidal pattern, increased risk of fetal acidemia
what can alleviate cord compression?
-instillation of normal saline
