Fetal Monitoring: Antenatal, Intrapartum, and Postpartum Guidelines
Intrapartum Monitoring: The Core Recommendation
For low-risk pregnancies, structured intermittent auscultation (SIA) is equivalent to continuous electronic fetal monitoring (EFM) for preventing neonatal mortality and cerebral palsy, while significantly reducing cesarean deliveries (NNH=20) and instrumental vaginal births (NNH=33). 1
Choosing Your Monitoring Method
Low-Risk Patients:
- Use structured intermittent auscultation with 1:1 nurse-to-patient ratio 1
- Frequency: Every 15-30 minutes in active first stage; every 5 minutes during second stage with pushing 1
- Technique requires: 60-second FHR count between contractions, 60-second count after contractions to assess fetal response 1
High-Risk Patients - Continuous EFM is indicated for:
- Abnormalities detected on SIA
- Maternal conditions (diabetes, hypertension)
- Fetal growth restriction
- Oligohydramnios
- Post-term pregnancy
- Oxytocin augmentation 1
Critical caveat: Avoid routine admission EFM tracings in low-risk pregnancies—they increase interventions (epidural NNH=19, continuous EFM NNH=7, fetal scalp testing NNH=45) without improving neonatal outcomes 1
Interpreting Continuous EFM: The DR C BRAVADO System
Use this systematic approach 1:
DR = Determine Risk (assess maternal/fetal risk factors)
C = Contractions (assess frequency, duration, intensity)
BRA = Baseline Rate (110-160 bpm normal)
V = Variability (moderate variability is reassuring)
A = Accelerations (presence indicates pH ≥7.20)
D = Decelerations (classify type and severity)
O = Overall assessment (categorize I, II, or III)
Management Based on EFM Categories
Category I (Normal): No intervention needed 1
Category II (Indeterminate - most common): 1 Implement intrauterine resuscitation in this specific order:
- Change maternal position
- Assess vital signs (temperature, BP, pulse)
- Discontinue oxytocin immediately
- Initiate oxygen 6-10 L/min
- Perform vaginal exam (check cord prolapse, rapid descent, bleeding)
- Give IV fluid bolus
- Assess fetal pH via scalp/acoustic stimulation
- Give amnioinfusion for recurrent moderate-to-severe variable decelerations (reduces cesarean NNT=8, low Apgar NNT=33, low cord pH NNT=8) 1
- Consider expedited delivery if no improvement
Category III (Abnormal): Expedite delivery via operative vaginal or cesarean delivery 1
Antenatal Surveillance
Initiate antepartum fetal surveillance when:
- Estimated fetal weight <10th percentile (start 26-28 weeks) 2
- Maternal diabetes, hypertension, or other high-risk conditions 3
- Suspected intrauterine growth restriction (IUGR) 2
IUGR-Specific Doppler Protocol 2
Primary tool: Umbilical artery Doppler (reduces perinatal mortality and unnecessary interventions)
Frequency:
- Weekly Doppler when IUGR suspected with normal end-diastolic flow
- 2-3 times per week when:
- Absent or reversed end-diastolic flow present
- Oligohydramnios complicates IUGR
Additional surveillance:
- Twice weekly nonstress testing with weekly amniotic fluid assessment, OR
- Weekly biophysical profile testing 2
Middle cerebral artery and ductus venosus Doppler add prognostic value in preterm IUGR but follow variable progression patterns 2
Postpartum Considerations
Measure cord blood gases after any abnormal FHR tracing to document metabolic acidosis (pH <7.00 or base deficit >12 mmol/L)—one of four essential criteria for determining acute intrapartum hypoxic events causing cerebral palsy 1
Key Evidence Limitations
The only proven benefit of continuous EFM is reduction in neonatal seizures (NNT=661)—it does not reduce cerebral palsy or neonatal mortality 1. This 99% false-positive rate explains the increased operative interventions without improved long-term outcomes 4.
Documentation Requirements
- Regular physician and nurse review of tracings during labor
- Use flow sheets/partograms for systematic documentation
- Archive FHR tracings (electronic records preferred)
- Ensure written documentation coincides with automated processes 1
Newer technologies (fetal ECG with ST-segment analysis, fetal pulse oximetry) show limited benefit: FECG reduces operative vaginal deliveries (NNT=50) and scalp sampling (NNT=33) 1, but pulse oximetry does not reduce cesarean rates 1.