Because of the high inter-observer differences in fetal monitoring interpretation, the National Institute of Child Health and Human Development (NICHD) established a classification system for EFM tracings.

This effort was jointly supported by the American College of Obstetricians and Gynecologists (ACOG), and the Society for Maternal-Fetal Medicine (SMFM.

The result is a three-tiered system for categorizing fetal monitoring tracings, Categories I, II, and III.

Category I (Normal)

• Normal baseline rate (110-160 BPM)
• Normal baseline variability (Moderate, 6-25 BPM)
• No late or variable decelerations
• May or may not be accelerations
• May or may not be early decelerations

Category II (Indeterminant)

Neither Category I nor Category II

Category III (Abnormal)

• Persistent Sinusoidal Pattern, regardless of variability,

or

• Loss of variability (Absent or Minimal), plus:

Recurrent late decelerations, or

Recurrent variable decelerations, or

Bradycardia