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
