INTRAPARTUM FETAL HEART

RATE MONITORING

DEFINITIONS

Baseline Fetal Heart Rate (FHR): The mean FHR rounded to increments of 5
beats/min during a 10-minute segment. Normal FHR baseline is 110–160
beats/minute.

Tachycardia: FHR baseline is >160 beats/min.

Bradycardia: FHR baseline is <110 beats/min.

Baseline variability describes fluctuations in the baseline FHR that are irregular
in amplitude and frequency. It is a reflection of the autonomic interplay between

Non-hypoxic explanations    include:

Maternal:   medications (β-adrenergic   agonists    [terbutaline],  atropine,

scopolamine),   fever,  thyrotoxicosis

Fetal:  repetitive  accelerations   (from   fetal   movements), fetal

tachyarrhythmias,   prematurity

Non-hypoxic explanations    include:

Maternal    medications:    β-adrenergic    blockers,   local   anesthetics

Fetal   arrhythmia: congenital  heart   block   (associated with    maternal

lupus)