Fetal Monitoring & Assessment Flashcards
Normal HR variability in the fetus is a reflection of what?
intact neurological modulation
The loss of HR variability in the fetus is the single most reliable sign of what?
fetal compromise
What medication is most associated with a decrease in fetal HR variability?
narcotics
What is normal fetal HR acceleration at 32 weeks or more?
15 beats for 15 seconds
How is fetal bradycardia defined?
fetal HR < 110 bpm for a 10 minute period
fetal bradycardia is associated with mother’s who have this systemic disease.
Lupus
How is fetal tachycardia defined?
- mild = 161-180
- severe = >180
When does an early deceleration begin and end?
begins with the onset of contraction and ends with its completion
What is the cause of variable decelerations?
cord compression
What is the most common periodic change in the fetal HR in labor?
variable deceleration
When does a late deceleration begin?
begins 20-30 seconds after the contraction
What is the cause of late deceleration?
uterine-placental insufficiency
What is the cause of early deceleration?
head compression causes a vagal stimulation
These 2 criteria must be met for internal fetal HR monitoring to be done.
- fetal membranes must be ruptured
- cervix must be partially dilated
A patient is doing well and has no significant findings. She can proceed with labor as tolerated. What category is she under for classifications of fetal tracings?
Category 1
This category is associated with abnormal tracings and abnormal fetal acid-base.
Category 3
This category is indeterminate. It requires further evaluation and continued surveillance.
Category 2
What is a normal finding on a scalp stimulation test?
- stimulation of the fetal scalp with constant pressure results in an increase in FHR by 10 bpm
What is the goal of antepartum fetal surveillance?
identification of suspected fetal compromise before progressive metabolic acidosis leads to fetal death
What is a normal finding on a non stress test?
2 accelerations of the FHR > 15 bpm above the baseline lasting at least 15 seconds within 20 minutes
What is a positive test on a contraction stress test?
- repetitive late decelerations following 50% or more of the contractions
What is a contraction stress test done for?
assess if a vaginal delivery attempt can be undertaken
A biophysical profile looks at these 4 factors.
- fetal breathing
- fetal movement
- fetal tone
- amniotic fluid volume
What is a biophysical profile?
- ultrasound evaluation for fetal well being
What biophysical profile score is considered normal?
What biophysical profile score is considered abnormal?
- normal = 8/8
- abnormal = 4/8
Potter’s syndrome aka renal agenesis is associated with what amniotic fluid abnormality?
- oligohydramnios
How is oligohydramnios defined?
an amniotic fluid index <5 cm or a max vertical pocket <2 cm
How is polyhydramnios defined?
- amniotic fluid index >24cm
- max vertical pocket >8cm
What is the most common cause of MILD polyhydramnios?
idiopathic
What are the 5 causes of polydramnios?
- fetal malformation (most GI)
- twin-twin transfusion
- hydrops fetalis
- DM
- idiopathic
A normal umbilical cord consists of how many arteries and veins?
2 arteries and 1 vein
When is a single umbilical artery diagnosed?
at the time of second trimester ultrasound
Doppler studies are used to assess what?
placental function
What should you do if the fetal tracings are a category III?
prompt delivery!
What should you do if the fetal tracings are a category II and the fetus responds to scalp stimulation?
continue surveillance
What should you do if the fetal tracings are a category II and the fetus does not respond to scalp stimulation?
consider delivery
