Chapter 191 Fetal Heart Rate Testing: Reduced Variability
INTRODUCTION
Description: Reduced variability is characterized by a reduction in the normal variation in heart rate from beat to beat that may signal fetal stress.
Prevalence: Reduced variability is a common finding when the fetal status is compromised. It also occurs when the fetus is sleeping.
ETIOLOGY AND PATHOGENESIS
Causes: Fetal hypoxia with neurologic depression (when decelerations are absent, reduced variability is unlikely to result from hypoxia); extreme prematurity; maternal sedation; fetal sleep.
