Intrapartum fetal cardiac arrhythmias.

Fifteen cases of fetal cardiac arrhythmia were detected by direct fetal electrocardiogram (FECG) during intrapartum fetal monitoring. The frequency of arrhythmia of 12.4/1000 monitored births. Thirteen of the arrhythmias were supraventricular. Atrial bigeminy was the most commonly observed arrhythmia, followed by atrial trigeminy. Two cases of ventricular arrhythmia were noted, one of which was a case of ventricular tachycardia. Arrhythmias were not related to drug treatment or to stage of labor. Variable decelerations occurred in association with arrhythmias in 73% of the cases. There were no nuchal cords seen at delivery, nor were there any instances of intrapartum fetal distress, fetal acidosis, or low Apgar scores associated with any arrhythmia. All arrhythmias resolved spontaneously without treatment. The neonatal course was uncomplicated in all cases. Intrapartum fetal arrhythmia is best detected by direct FECG. Appropriate management should include close observation for ominous fetal heart rate (FHR) patterns and fetal acid-base-studies. At present, there is no indication for drug treatment of intrapartum arrhythmia.