FHR Flashcards
When is baseline FHR measured
When woman has no contractions and fetus is not expierencing episodic FHR changes
How can a normal baseline FHR be obtained
auscultation, ultrasound, doppler or by continuous internal direct fetal electrode
What are the causes of fetal bradycardia
hypoxia
prolonged maternal hypoglycemia
fetal acidosis
admin of analgesic drugs to mom
hypothermia
epidural
maternal or fetal hypotension
Prolonged umbilical cord compression
fetal congenital heart block
When is bradycardia a ominous sign?
When accompanied with decrease in baseline variability and late decelerations
What could be causes of fetal tachycardia
Early compensatory response to asphyxia
Fetal hypoxia
Maternal fever
Maternal dehydration, amnionitis, drugs
Maternal hyperthyroidism, anxiety
Fetal anemia
Prematurity
Fetal infection
Chronic hypoxemia
Congenital amonalies
Fetal heart failure
Fetal arrhythmias
When is fetal tachycardia considered an omnious sign?
accompanied by decrease in variablility and late decels
What is absent or minimal variability
caused by fetal acidemia secondary to uteroplacental insufficiency, cord compression, a preterm fetus, maternal hypotension, uterine hyperstimulation, abruptio placenta or fetal dysrhythmia
What are the interventions to uteroplacental blood flow and perfusion through umbilical cord?
Lateral positioning of mother
Increase IV fluid rate to improve maternal circulation
admin O2 8-10L by mask
Internal fetal monitoring
document and report
What does moderate viablility indicate
autonomic and CNS of fetus are well developed and oxygenated well
When does Marked variability occurs?
greater than 25 bpms of flucuation in baseline
Cord prolapes or compression, maternal hypotension, uterine hyperstimulation, abruptio placenta
What are the interventions for marked variability
determining cause, if possible
Lateral positioning
increasing IV rate
admin 02 8-10L by mask
discontinue oxytocin infusion
observe for changes in tracing
Internal fetal monitoring
FHR variability is an important clinical indicator that is predictive of ?
Fetal acid base balance and cerebral tissue perfusion
How many BPM is absent variablility
range undectable
How many BPM is minimal variablility
fever than 5 bpm
How many BPM is moderate variablility
6-25bpm
How many BPM is marked variablility
more than 25bpm
When are early decels usually seen and are thought to be the result of?
-active stage of any normal labor, during pushing, crowning or vaccum extraction
-fetal head compression that results in reflex vagal response
Late decels are associated with
uteroplacental insufficiency - blood flow is decreased that fetal hypoixa or myocardial depression exists
What are conditions that decrease uteroplacental perfusion with resultant decels?
maternal hypotension
gestational HTN
placental agin secondary to diabetes and postmaturity
hyperstimulation via oxytocin
maternal smoking
anemia and cardiac disease
*imply some degree of fetal hypoxia
Variable decels are assoc with
Cord compression
Classified either 2 or 3 depending on change in baseline variability
What are some factors assoc with prolonged decels?
prolonged cord compression, abruptio placenta,cord prolapse, supine maternal position, vaginal exam, fetal blood sampling, maternal seizures, regional anesthesia, uterine rupture
Sinusoidal pattern
visually apparent smooth sinewave like undulating pattern in FHR with a cycle freq of 3-5bpm that persists for more than 20 min
What could cause sinusoidal pattern
derangement of CNS control of FHR and occurs when a severe degree of hypoxia seconday to fetal anemia and hypovolemia is present.
*always category 3
** to correct a fetal intrauterina transfusion would be needed.
