Intrapartum Abnormal Fetal HR Tracing - Causes of Variability & Decelerations - Differential Diagnosis Algorithm

Minimal/Absent Variability (< 5 bpm):

 • Fetal sleep

 • Prematurity

 • Medications (analgesia, sedatives)

 • Hypoxic acidemia

 • Congenital anomalies

Marked Variability (> 25 bpm):

 • Mild hypoxia

Sinusoidal Pattern Variability: 

 • Severe fetal anemia (Hgb < 70)

 • Tissue hypoxia in fetal brain stem

Variability Absent Accelerations:

 • Hypoxic acidemia

 • Fetal abnormality

Early decelerations:

 • Fetal head compression (mirror contractions)

Variable decelerations:

 • Cord compression

 • Fetal acidemia if complicated variable decelerations

Late decelerations:

 • Uteroplacental insufficiency

 • Maternal hypotension

 • Reduced maternal arterial oxygen saturation

 • Hypertonic uterus

 • Fetal acidemia

Prolonged deceleration:

 • Hypertonic uterus

 • Unresolving umbilical cord compression

 • Maternal hypotension

 • Maternal seizure

 • Rapid fetal descent



#Decelerations #Variability #FetalHR #FetalHeartRate #Tracing #Differential #Diagnosis #Algorithm #Causes #Obstetrics #OBGyn