Electronic fetal heart rate monitoring in five fetuses with Ebstein's anomaly

It is not clear whether fetuses with Ebstein's anomaly are likely to show abnormalities on electronic fetal heart rate (FHR) monitoring during labor.

We performed retrospective analysis of FHR monitoring results obtained between 2.5 and 0.5 h prior to delivery in all of five fetuses prenatally diagnosed as having Ebstein's anomaly and born at our institution during the period between March 2005 and July 2011. All five mothers attempted to give birth vaginally. The results of FHR monitoring in 100 consecutive women with otherwise healthy singletons who attempted vaginal delivery were included as controls.

The absence of FHR acceleration (4/5 [80%]), decreased baseline FHR variability (3/5 [60%]) and late deceleration (4/5 [80%]) were seen significantly more often in the five fetuses with Ebstein's anomaly than the 100 fetuses born to control women (6.0%, 6.0%, and 10%, respectively).

Fetuses with Ebstein's anomaly during labor were likely to exhibit absent acceleration, decreased baseline FHR variability and late deceleration compared to infants without cardiac structural anomalies.