Obgyn · Year 3 · from Obgyn
Case 1: Non-Reassuring Nonstress Test with Biophysical Profile
Patient Demographics
- Age: 34 years
- Sex: Female
- Occupation: Elementary school teacher
Chief Complaint
"I'm here for my weekly fetal testing because of my diabetes."
History of Present Illness
The patient is G2P1 at 34 weeks gestation with pregestational type 2 diabetes. She has been on insulin throughout pregnancy with fair glycemic control (HbA1c 7.1% at 28 weeks). She presents for routine antenatal testing. She reports good fetal movement, no contractions, no vaginal bleeding, and no leakage of fluid.
Past Medical History
- Type 2 diabetes mellitus x 6 years
- Obesity (BMI 34 kg/m2)
- Prior term vaginal delivery (infant 4,200 grams)
Antenatal Testing Protocol
- Twice-weekly NST initiated at 32 weeks for pregestational diabetes
Nonstress Test Results
Initial NST (20 minutes):
- Baseline fetal heart rate: 145 bpm
- Variability: Minimal (amplitude <5 bpm)
- Accelerations: None observed
- Decelerations: None
- Contractions: Occasional, irregular
Extended NST (40 minutes):
- Still no accelerations meeting criteria (15 bpm x 15 seconds)
- Variability remains minimal
- Interpretation: Non-reactive NST
Vibroacoustic Stimulation
- Applied to maternal abdomen over fetal head
- No change in fetal heart rate pattern
- Still non-reactive after stimulation
Next Step: Biophysical Profile
BPP Results:
| Component | Finding | Score |
|---|---|---|
| NST | Non-reactive | 0 |
| Fetal Breathing | Present (>30 seconds observed) | 2 |
| Fetal Movement | 3+ movements observed | 2 |
| Fetal Tone | Flexion/extension seen | 2 |
| Amniotic Fluid (MVP) | 4 cm (normal) | 2 |
Total BPP Score: 8/10
Interpretation
- BPP 8/10 with non-reactive NST is considered NORMAL
- The non-reactive NST is likely due to fetal sleep state
- All other parameters normal, indicating adequate oxygenation
- No evidence of fetal hypoxia or acidosis
Management
- Reassurance provided to patient
- Continue twice-weekly testing
- Return in 3-4 days for repeat NST/modified BPP
- Glucose log reviewed - adjustments made to evening NPH
Teaching Points
- Non-reactive NST alone does not indicate fetal distress
- Fetal sleep cycles (20-40 minutes) are the most common cause of non-reactive NST
- BPP score of 8/10 with normal fluid is reassuring
- High negative predictive value: normal testing strongly predicts healthy fetus
Clinical Image
Image Description: Fetal heart rate tracing demonstrating a non-reactive nonstress test with minimal variability and absence of accelerations over a 20-minute period. The tracing shows a stable baseline rate of approximately 145 bpm without decelerations.
Attribution: Educational illustration. Medical education resource demonstrating NST interpretation.