The significance of antepartum variable decelerations.

A total of 4886 nonstress tests were reviewed to establish the relationship between antepartum variable decelerations and perinatal outcome. The association between various fetal heart rate components and variable decelerations was also studied. The incidence of variable decelerations, defined as three or more decelerations greater than or equal to 15 bpm lasting at least 15 seconds in a 20-minute period, was 1.3%. The results suggest that in the presence of variable decelerations: there is a higher incidence of fetal distress in labor, low Apgar scores, neonatal intensive care unit admissions, and nuchal cord involvement; the presence of accelerations and normal variability is associated with good neonatal outcome, whereas their absence is associated with adverse outcome; the presence of accelerations or good variability is not independently correlated with neonatal outcome.