Fetal heart tracing

Components

• Baseline: normal range is from 110-160 bpm
• Variability
  • Absent
  • Minimal: less than 5 bpm
  • Moderate (normal): 5 to 25 bpm (reassuring)
  • Marked: more than 25 bpm
• Accelerations: rise from baseline of at least 15 bpm lasting at least 15 sec (or 10x10 if <30 weeks)
• Decelerations: decrease from baseline of at least 15 bpm lasting at least 15 sec (or 10x10 if <30 weeks)
  • Early: associated with contractions, possibly related to head compression, and clinically benign
  • Late: placental insufficiency or decreased perfusion to the fetus
  • Variable: may reflect transient cord compression
  • Prolonged: ≥15 bpm and lasting ≥2 minutes but <10 minutes; if > 10 min, then it's a baseline change

Classification

• Category I (normal/reassuring): all of the following must be present
  • A baseline FHR of 110 to 160 bpm
  • Moderate FHR variability (6 to 25 bpm)
  • Absence of late or variable FHR decelerations
  • Early decelerations may or may not be present
  • Accelerations may or may not be present
• Category 2 (atypical/indeterminate/non-reassuring)
  • Does not meet criteria for categories 1 or 2
  • Not predictive of fetal outcomes
• Category 3 (abnormal/fetal distress): at least one of the following must be present
  • Absent variability with recurrent late decelerations
  • Absent variability with recurrent variable decelerations
  • Absent variability with bradycardia
  • A sinusoidal pattern