Can electronic fetal monitoring identify preterm neonates with cerebral white matter injury?

Abstract

Objective: Although preterm delivery occurs in only 10% of all births, these infants are at high risk for cerebral white matter injury and constitute a third of all cerebral palsy cases. Our objective was to estimate if electronic monitoring can identify preterm fetuses diagnosed with brain injury during the neonatal period.

Methods: In this case-control study, 150 consecutive neonates with ultrasonography-diagnosed cerebral white matter injury were matched by gestational age within 7 days to 150 controls with normal head ultrasonograms. Tracings were retrieved for 125 cases (83%) and 121 controls (81%) and reviewed by 3 perinatologists blinded to outcome. Vaginal (64 cases, 72 controls) and cesarean deliveries (61 cases, 49 controls) were analyzed separately.

Results: There was no difference in baseline heart rate, tachycardia, bradycardia, short-term variability, accelerations, reactivity, number or types of decelerations, or bradycardic episodes between cases and controls in either the vaginal or cesarean delivery groups. For the 6 neonates with metabolic acidosis severe enough to increase the risk for long-term neurologic morbidity, there was a significant increase in baseline amplitude range less than 5 beats per minute; however, its positive predictive value in predicting severe metabolic acidosis was only 7.7%. Increasing late decelerations were associated with decreasing umbilical arterial pH and base excess, but were not significantly different in the acidosis and control groups (1.0 +/- 1.8, 0.55 +/- 1.23 late decelerations per hour, P = .39).

Conclusion: Although decreased short-term variability and increased late decelerations are associated with decreasing umbilical arterial pH and base excess, electronic fetal monitoring is unable to identify preterm neonates with cerebral white matter injury.