Fetal Movement Counting - Daily Kick Count
- Maternal method to screen fetal well-being, usually from 28 weeks.
- "Count-to-Ten" (Cardiff):
- Feel 10 movements. Normal: within 2 hours.
- Report if: <10 movements in 2 hours, or no movements in 12 hours.
- Sadovsky: Count for 1 hour (TID, post-meal). Report if <3 movements/hour.
- ↓ Movements: Investigate with NST/BPP.
⭐ Fewer than 10 movements in 2 hours is a key indicator for further fetal assessment.
Non-Stress Test (NST) - Happy Heart Traces
- Evaluates fetal well-being via Fetal Heart Rate (FHR) accelerations with fetal movements.
- Reactive (Term ≥32 wks): ≥2 accelerations of ≥15 bpm lasting ≥15 sec in 20 min. (📌 15-15-2 rule)
- Reactive (Preterm <32 wks): ≥2 accelerations of ≥10 bpm lasting ≥10 sec in 20 min. (📌 10-10-2 rule)
- Non-Reactive: Criteria not met in 40 min. Requires further evaluation (e.g., Biophysical Profile - BPP).
⭐ Most common reason for a non-reactive NST is a fetal sleep cycle.
Contraction Stress Test (CST) - Uterine Challenge
- Assesses fetal heart rate (FHR) response to uterine contractions, indicating uteroplacental reserve.
- Requires 3 contractions (each ≥40s) in 10 min (spontaneous or induced via oxytocin/nipple stimulation).
- Interpretations:
Result Finding Negative No late or significant variable decelerations. Positive Late decelerations with ≥50% of contractions. Equivocal Intermittent late/variable decels; or decels with hyperstim. Unsatisfactory <3 contractions in 10 min; poor tracing.
⭐ A positive CST is associated with an increased risk of fetal distress in labor, IUGR, and low Apgar scores.
Biophysical Profile (BPP) - Fetal Five Score
Assesses fetal well-being. 5 parameters, 0 or 2 points each. Max 10. 📌 BATMN.
| Parameter | Normal (Score 2) | Abnormal (Score 0) |
|---|---|---|
| Fetal Breathing (FBM) | ≥1 episode ≥30s/30min | Absent or <30s/30min |
| Gross Body Moves (GBM) | ≥3 distinct moves/30min | <3 moves/30min |
| Fetal Tone (FT) | ≥1 active extension/flexion | Slow ext/flex, or absent |
| Amniotic Fluid Vol (AFV) | MVP >2cm or AFI >5cm & <25cm | MVP ≤2cm or AFI ≤5cm |
| Non-Stress Test (NST) | Reactive | Non-reactive |
- Score 8-10: Normal. Low risk. Repeat as indicated.
- Score 6: Equivocal. Repeat 12-24h. Deliver if oligo/term (≥37wks).
- Score ≤4: Abnormal. High risk. Deliver.
- Score 0-2: Severe compromise. Deliver STAT.
⭐ BPP is a better predictor of fetal pH than NST alone, especially in IUGR.
Doppler Velocimetry - Vascular Vibes
Non-invasive assessment of fetal blood flow, placental function, and fetal well-being.
- Indices: S/D Ratio ($S/D$), PI ($(S-D)/Mean$), RI ($(S-D)/S$).
| Vessel | Parameter | Normal | Abnormal & Significance |
|---|---|---|---|
| UA | S/D, PI, RI | S/D <3.0 (post 30wk) | ↑Indices (placental insufficiency); AEDF/REDF (severe IUGR) |
| MCA | PI, PSV | High resistance; CPR (MCA PI/UA PI) >1 | ↓PI (brain sparing); PSV >1.5 MoM (anemia); CPR <1 (risk) |
| DV | PI, 'a' wave | Forward flow | ↑PI, absent/reversed 'a' wave (cardiac decompensation) |
⭐ Umbilical Artery REDF (Reversed End-Diastolic Flow) indicates severe fetal compromise, often necessitating urgent delivery.
High‑Yield Points - ⚡ Biggest Takeaways
- Reactive NST (≥2 accelerations) is reassuring; non-reactive needs BPP or CST.
- BPP score ≤4/10 indicates fetal compromise; 8-10/10 is normal.
- Positive CST (late decelerations) suggests uteroplacental insufficiency.
- Oligohydramnios (AFI <5 cm) is a key concern for fetal well-being.
- Absent/Reversed End-Diastolic Flow (AREDF) in umbilical artery Doppler is ominous.
- MCA Doppler PSV is crucial for detecting fetal anemia.
- Normal FHR variability (5-25 bpm) indicates good fetal oxygenation.
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