Labor and Delivery Pearls Flashcards
Define the baseline FHR pattern.
The mean FHR rounded to increments of 5 bpm during a 10 minute segment; must be a minimum of 2 minutes in any 10 minute segment
Define baseline variability in the FHR pattern.
Fluctuations in the FHR of two cycles per minute or greater
How is baseline variability quantified?
Amplitude of peak-to-trough in bpm
What are the 4 definitions of baseline variability?
Absent
Minimal
Moderate (normal)
Marked
Define absent baseline variability.
Amplitude range undetectable
Define minimal baseline variability.
Amplitude range detectable but less than or equal to 5 bpm
Define moderate (normal) baseline variability.
Amplitude range 6-25 bpm
Define marked baseline variability.
Amplitude range >25 bpm
Define acceleration of FHR.
Increase in the FHR from the most recently calculated baseline
How is the duration of a FHR acceleration defined?
Time from initial change in FHR from the baseline to the return to baseline
Define FHR acceleration from 32 weeks and beyond.
Acme of 15+ bpm above baseline, duration of 15+ seconds, but less than 2 minutes
Define FHR acceleration before 32 weeks.
10 bpm or more above baseline, duration of 10+ seconds, but less than 2 minutes
Defined prolonged acceleration.
Longer than 2 minutes but shorter than 10 minutes
Define baseline change in FHR.
If an acceleration lasts 10 minutes or longer, it is a baseline change
Define FHR bradycardia.
Baseline FHR <110 bpm
Define early deceleration.
Deceleration associated with a uterine contraction; gradual (onset to nadir 30 seconds or more) decrease with return to baseline; nadir of the deceleration occurs at the same time as the peak of the contraction
Define late deceleration.
Deceleration associated with a uterine contraction, gradual (onset to nadir 30 seconds or more) decrease with return to baseline; onset, nadir, and recovery occur after the beginning, peak, and end of the contraction, respectively
Define FHR tachycardia.
Baseline FHR >160 bpm
Define variable acceleration.
Abrupt (onset to nadir less than 30 seconds) decrease in the FHR below the baseline; decrease is 15+ bpm, with a duration of 15+ seconds but less than 2 minutes
Define prolonged deceleration.
Visually apparent decrease in the FHR below the baseline; deceleration is 15 bpm or more, lasting 2 minutes or more but less than 10 minutes from onset to return to baseline
Define a reactive nonstress test.
2+ accelerations occur in 20 minutes.
Define a non-reactive stress test.
No accelerations noted over 40 minutes.
How is a contraction stress test performed?
Administer pitocin or stimulate nipples until 3 contractions in 10 minutes
Define a positive (non-reassuring) contraction stress test.
Late decelerations following 50% or more of the contractions
Define a negative (reassuring) contraction stress test.
No late or significant variable decelerations
Define an equivocal-suspicious pattern of a contraction stress test.
Intermittent late or significant variable decelerations
Define an equivocal-hyperstimulatory contraction stress test
Decelerations with contractions more frequent than q2 minutes or lasting >90 seconds
Define an unsatisfactory contraction stress test.
Tracing is uniterruptable or contractions are fewer than 3 in 10 minutes
How is a biophysical profile assessed and scored?
2 points for each of the following in a 30 minute period:
- NST
- Fetal breathing (1+ episodes of breathing lasting 30+ seconds)
- Fetal movements (3+ discrete body or limb movements)
- Fetal tone (1+ episode of extension of extremity with return to flexion or opening or closing of the hand)
- AFI (amniotic fluid index) (single vertical pocket >2cm)
How is a biophysical profile interpreted?
8-10: reassuring
6: equivocal - deliver if mature; if not, administer steroids and repeat in 24 hours
4 or less: delivery unless extremely preterm
What are the components of a modified biophysical profile (BPP)?
BPP = NST + AFI
Define the phases/stages of labor.
First: onset of labor to complete dilation
*Latent: cervical effacement; variable
*Active: rapid dilation, relatively fixed time
Second: complete dilation to delivery
Third: delivery of infant to delivery of placenta
Define fetal lie.
Axis of the fetus (longitudinal, transverse, oblique)
Define presentation.
Fetal part at the cervix (cephalic, breech, shoulder)