Preterm deliveries account for approximately one third of cerebral palsy cases. Injury to the cerebral white matter is the most common brain damage found in neonates and is a significant precursor to cerebral palsy. White matter injury almost always occurs before 34 weeks’ gestation, and an estimated 60 to 100 percent of infants who survive the injury develop cerebral palsy. Most cases of cerebral palsy are not diagnosed until one to two years of age. Therefore, Althus and colleagues investigated the effectiveness of electronic fetal monitoring in identifying preterm infants with cerebral white matter injury.
The case-control study included infants admitted to a university hospital neonatal intensive care department. The authors identified 150 consecutive infants whose head ultrasonograms showed evidence of cerebral white matter injury. Each infant was matched to a control infant with a normal ultrasonogram, whose gestational age was within seven days of the index infant. Infants with congenital and chromosomal abnormalities were excluded. Electronic fetal monitoring tracings were available for 125 (83 percent) of the case group and 121 (81 percent) of the control infants. For each infant, three independent reviewers evaluated the last hour of measurable tracings before cesarean or vaginal delivery using guidelines from the National Institute of Child Health and Human Development. Cesarean and vaginal deliveries were analyzed separately.
In cesarean and vaginal deliveries, the control and case groups were comparable in maternal and obstetric factors. Among vaginal deliveries, preeclampsia was significantly more common in the case group compared with the control group. However, because the case group had a significant decrease in preeclampsia among cesarean deliveries, researchers found no significant difference overall in the risk of preeclampsia between case and control groups. In vaginal and cesarean deliveries, the case group had a significantly increased risk of intraventricular hemorrhage compared with the control group. The time from the last measurable tracing to vaginal delivery was also comparable in both groups. Fetal monitoring showed no significant differences in fetal heart function between case and control groups for vaginal and cesarean deliveries. The authors conclude that electronic fetal monitoring did not identify preterm infants with cerebral white matter injury.