Continuous Electronic Fetal Monitoring (Option C)
For a primigravida at 39 weeks with a fetus at the 8th percentile (indicating fetal growth restriction), continuous electronic fetal monitoring during labor is the best intrapartum surveillance method to prevent complications and promote health outcomes. 1
Clinical Rationale for High-Risk Classification
A fetus at the 8th percentile represents intrauterine growth restriction (IUGR), which automatically classifies this pregnancy as high-risk requiring enhanced intrapartum surveillance. 1
Growth restriction indicates a chronic hypoxic state that significantly increases the fetus's vulnerability to labor stress, as the growth-restricted fetus has limited physiologic reserve to tolerate the normal hypoxic challenges of contractions. 1
The American College of Radiology guidelines specifically identify IUGR as requiring consideration for continuous monitoring during labor due to increased risk of uteroplacental insufficiency and intrapartum hypoxia. 1
Why Not Intermittent Auscultation?
While structured intermittent auscultation is the preferred method for low-risk pregnancies (checking every 15-30 minutes in active labor and every 5 minutes during second stage), this patient does not qualify as low-risk. 2, 3
Intermittent auscultation is only appropriate when there are no risk factors for fetal compromise. 3
In high-risk pregnancies like growth restriction, continuous monitoring can detect patterns of fetal compromise that intermittent auscultation may miss, particularly in fetuses already compromised by chronic hypoxia. 1
The only demonstrable benefit of continuous EFM—reduction in neonatal seizures (NNT = 661)—becomes more clinically relevant in high-risk populations where the baseline risk of hypoxic injury is already elevated. 2, 1
Why Not Maternal Vital Signs Alone?
Maternal vital signs monitoring alone does not assess fetal wellbeing, which is the primary concern for detecting intrapartum hypoxia and preventing adverse neonatal outcomes. 3
While maternal vital signs should be monitored as part of comprehensive care, they cannot substitute for direct fetal heart rate assessment in detecting fetal compromise during labor. 2
Implementation Strategy
Use systematic interpretation with the DR C BRAVADO mnemonic (Determine Risk, Contractions, Baseline Rate, Variability, Accelerations, Decelerations, Overall assessment) to guide clinical decision-making. 1
Be prepared for operative delivery if non-reassuring fetal heart rate patterns develop, as growth-restricted fetuses have limited physiologic reserve. 1
Apply general measures for Category II tracings (indeterminate patterns): vaginal examination, maternal vital signs, oxygen administration, position changes, intravenous fluids, and fetal pH assessment with acoustic or scalp stimulation. 2
Expedite delivery with operative vaginal or cesarean delivery for Category III tracings (absent baseline variability with recurrent decelerations and/or bradycardia). 2
Critical Caveat
While continuous EFM increases cesarean delivery rates (NNH = 20) and instrumental vaginal births (NNH = 33) in low-risk populations without improving outcomes 2, this trade-off is acceptable in high-risk situations like fetal growth restriction where the fetus is already compromised and the risk of intrapartum hypoxic injury is substantially elevated. 1