NST and other labor tests

Question 1

normal fetal HR

Answer 1

normal 110 - 160 / min

Question 2

antepartum fetal surveillance - tests

Answer 2

1. nonstress test
2. biophysical profile
3. contraction stress test
4. Doppler sonography of the umbilical artery

Question 3

nonstress test - description

Answer 3

reactive: 2 or more accelerations
abnormal: less than 2 accelerations or recurrent, variable or late decelerations

Question 4

Normal labor - accelerations

Answer 4

normal acceleratipns are an increase in HR of 15 or more beats per minute above the baseline for longer than 15-20 sec. If this happens twice in 20 mins, it is REASSURING or normal

Question 5

non reactive NST –> (next step)

Answer 5

vibroacoustic (maybe due to sleeping) –> if still nonreactive –>
Byophisical profile or contraction stress test
(no contraction if contraindication of labor like placenta previa or prior myomectomy)

Question 6

biophysical profile - description

Answer 6

nonstress test plus U/S assessment of: 
- amniotic fluid volume: 
- fetal breathing
- fetal movement 
- fetal tone 
(2 points per catergory)

Question 7

biophysical profile - normal vs abnormal

Answer 7

normal: 8-10 points
abnormal: 0-4 points, oligohydramnios
equivocal: 6 points

Question 8

6/10 biophysical test - next step

Answer 8

do it again in 24 hours

Question 9

contraction stress test - description

Answer 9

external fetal HR monitoring during spontaneous or induced (eg. oxytocin, nipple stimulation) uterine contraction

Question 10

contraction stress test - normal vs abnormal

Answer 10

normal: no late or recurrent variable declarations
abnormal: late decelerations with more than 50% of contractions

Question 11

Doppler sonography of the umbilical artery - description

Answer 11

evaluation of umbilical artery flow in fetal intrauterine growth restriction only

Question 12

Doppler sonography of the umbilical artery - normal vs abnormal

Answer 12

normal: high velocity diastolic flow in umibilical artery
abnormal: decreased, absent, or reserved end diastolic flow

Question 13

biophysical profile: details of every parameter

Answer 13

1. NST
2. single fluid pocket 2cm or more x 1 cm or amniotic fluid index more than 5%
3. fetal movements: 3 or more general body movements
4. fetal tone: 1 or more episode of flexion/extension of limbs or spine
5. fetal breathing: 1 or more breathing episodes for 30 or more sec

Question 14

decreased or absent fetal contraction –> next step

Answer 14

doppler
fetal HR?
YES –> NST
NO –> Transabdominal u/s

Question 15

normal labor - deceleration (types)

Answer 15

1. early
2. variable
3. late (most serious and dangerous)

Question 16

normal labor - early deceleration (description and cause)

Answer 16

• decrease in HR that occurs with contractions
• nadir of deceleration corresponds to peak of contraction
• gradual (30 or more sec from onset to nadir)
• head compression / can be normal fetal tracing

Question 17

normal labor - variable deceleration (description and cause)

Answer 17

• decrease in HR and return to baseline with no relationship with contraction
• abrupt (less than 3- sec from onset to nadir
• decrease 15 or more / min, duration 15 or more sec but less than 2 min
• umbilical cord compression or prolapse or oligohydramnios

Question 18

normal labor - late deceleration (description and cause)

Answer 18

• decrease in HR after contraction started. NO RETURN TO BASELINE UNTIL CONTRACTION ENDS
• nadir of deceleration occurs after peak of contraction
  gradual (30 or more sec from onset to nadir
• fetal hypoxia (eg. uteroplacental insuf)

Question 19

normal labor - cause of every type

Answer 19

1. early –> head compression
2. variable –> umbilical cord compression / prolapse / oligohydramnios
3. late –> fetal hypoxia

Question 20

how to reduce cord compression

Answer 20

maternal repositioning –> if fails –> amnioinfusion

Question 21

amnoinfusion

Answer 21

instillation of saline into uterine cavity for treatment of reccurentvariable decelerations due to umbiilical cord compression during labor

Question 22

uterine rupture - NST

Answer 22

late deceleration