Intrapartum fetal heart rate monitoring

1. Intrapartum fetal heart rate monitoring
Relationship to contraction Etiology
Early • Symmetric to contraction
• Nadir of deceleration corresponds to
peak of contraction
• Gradual (≥30 sec from onset to nadir)
• Fetal head compression
• Can be normal fetal
tracing
Late • Delayed compared to contraction
• Nadir of deceleration occurs after
peak contraction
• Gradual (≥30 sec from onset to nadir)
• Uteroplacental
insufficiency
Variable • Can be but no necessarily associated
with contractions
• Abrupt (<30 sec from onset to nadir)
• Decrease ≥15min; duration ≥15 sec
but < 2min
• Cord compression
• Oligohydramnios
• Cord prolapse