RNC-OB Exam: Fetal Assessment
EXAM QUESTIONS ANS ANSWERS
WITH RATIONALE | ALREADY
GRADED A | NEW UPDATE 2026
<1:5 L/S Ration - ANSWER-Fetal lungs are immature
>2:1 L/S Ration - ANSWER-Fetal lungs are mature
2 factors which sustain fetus for low O2 levels - ANSWER-High
HCT/HGB
Accels Criteria - ANSWER-- 15x15 bpm < 2 mins (if > 2 min =
prolonged)
- peak < 30 secs
- If < 32 wks, 10x10 > 10 sec
ACOG Guidelines for O2 Therapy - ANSWER-- Recurrent lates
- Prolonged decels
- Bradycardia
,- Minimal or absent variability
Acoustic Stimulation - ANSWER-- Over fetal head (startle reflex)
- No more than 3 stims lasting 3 sec, one minute apart
Acoustic Stimulation Contraindications - ANSWER-- Oligo
- <32 wk gestation
Adequate Ctx - ANSWER-- Every 2-3 min lasting 80-90 sec
- Intensity = 25-75 mmHg
- Resting Tone = <10-15 mmHg
- MVUs = 200-220
AFI - ANSWER-Measure of pockets of fluid in all 4 uterine quadrants
Alpha Fetal Protein - ANSWER-Protein secreted by liver of fetus
Amniocentesis - ANSWER-Analysis of amniotic fluid for cultures,
genetic studies, CNS anomalies, ventral wall defects, lung maturity
Amniocentesis risks 15-16 wks - ANSWER-Respiratory distress
Amniocentesis risks before 14 wks - ANSWER-Club foot
Amnioinfusion - ANSWER-- Room temp isotonic fluid (NS or LR)
- Used to stop variables by lifting fetal parts off of cord
Amnioinfusion Rate - ANSWER-- Initial = 250-500 mL over 30 mins
- Maintenance = 150-180 mL/hr
- Max = 1000 mL
Amniotic fluid = - ANSWER-Fetal pee
, Borderline Oligo - ANSWER-5-8 cm AFI
BPP - Amniotic Fluid Volume - ANSWER-- Normal = at least 1 2 cm
pocket (need total AFI of 5 if no 2 cm pocket)
- Abnormal = not enough AF is seen in the uterus
BPP - Body Movement - ANSWER-- Normal = 3 or > body movements
of arms, legs, or body
- Abnormal = <3 movements
BPP - Breathing Movement - ANSWER-- Normal = 1 or > breathing
movements lasting at least 60 sec (can have 2 30 sec)
- Abnormal = absent breathing movements
BPP - Muscle Tone - ANSWER-- 1st to go
- Normal = 1 flex/extend movement of arms, legs, or hands
- Abnormal = does not flex/extend
BPP - Nonstress Test - ANSWER-- Normal = 2 or > accels in 20 mins
- Abnormal = 1 or 0 accels
BPP Main Points - ANSWER-- Over 30 mins
- Start at 28 wks
- Valid for 7 days
- 2 pts = normal
- 0 pts = abnormal
BPP Score Meaning - ANSWER-- 8-10 = reassuring
EXAM QUESTIONS ANS ANSWERS
WITH RATIONALE | ALREADY
GRADED A | NEW UPDATE 2026
<1:5 L/S Ration - ANSWER-Fetal lungs are immature
>2:1 L/S Ration - ANSWER-Fetal lungs are mature
2 factors which sustain fetus for low O2 levels - ANSWER-High
HCT/HGB
Accels Criteria - ANSWER-- 15x15 bpm < 2 mins (if > 2 min =
prolonged)
- peak < 30 secs
- If < 32 wks, 10x10 > 10 sec
ACOG Guidelines for O2 Therapy - ANSWER-- Recurrent lates
- Prolonged decels
- Bradycardia
,- Minimal or absent variability
Acoustic Stimulation - ANSWER-- Over fetal head (startle reflex)
- No more than 3 stims lasting 3 sec, one minute apart
Acoustic Stimulation Contraindications - ANSWER-- Oligo
- <32 wk gestation
Adequate Ctx - ANSWER-- Every 2-3 min lasting 80-90 sec
- Intensity = 25-75 mmHg
- Resting Tone = <10-15 mmHg
- MVUs = 200-220
AFI - ANSWER-Measure of pockets of fluid in all 4 uterine quadrants
Alpha Fetal Protein - ANSWER-Protein secreted by liver of fetus
Amniocentesis - ANSWER-Analysis of amniotic fluid for cultures,
genetic studies, CNS anomalies, ventral wall defects, lung maturity
Amniocentesis risks 15-16 wks - ANSWER-Respiratory distress
Amniocentesis risks before 14 wks - ANSWER-Club foot
Amnioinfusion - ANSWER-- Room temp isotonic fluid (NS or LR)
- Used to stop variables by lifting fetal parts off of cord
Amnioinfusion Rate - ANSWER-- Initial = 250-500 mL over 30 mins
- Maintenance = 150-180 mL/hr
- Max = 1000 mL
Amniotic fluid = - ANSWER-Fetal pee
, Borderline Oligo - ANSWER-5-8 cm AFI
BPP - Amniotic Fluid Volume - ANSWER-- Normal = at least 1 2 cm
pocket (need total AFI of 5 if no 2 cm pocket)
- Abnormal = not enough AF is seen in the uterus
BPP - Body Movement - ANSWER-- Normal = 3 or > body movements
of arms, legs, or body
- Abnormal = <3 movements
BPP - Breathing Movement - ANSWER-- Normal = 1 or > breathing
movements lasting at least 60 sec (can have 2 30 sec)
- Abnormal = absent breathing movements
BPP - Muscle Tone - ANSWER-- 1st to go
- Normal = 1 flex/extend movement of arms, legs, or hands
- Abnormal = does not flex/extend
BPP - Nonstress Test - ANSWER-- Normal = 2 or > accels in 20 mins
- Abnormal = 1 or 0 accels
BPP Main Points - ANSWER-- Over 30 mins
- Start at 28 wks
- Valid for 7 days
- 2 pts = normal
- 0 pts = abnormal
BPP Score Meaning - ANSWER-- 8-10 = reassuring
