Prenatally diagnosed blocked atrial premature beats.

A case of persistent severe bradycardia in labor, diagnosed as blocked atrial premature beats, is presented. Simultaneous recording of fetal heart rate (FHR) and fetal electrocardiogram (FECG) during labor established an accurate diagnosis of an innocent fetal sinus bradycardia and differentiated it from fetal distress. This method should be applied in all cases of persistent fetal dysrhythmia, in order to differentiate it from hypoxic distress, and thus enable the obstetrician to avoid unnecessary cesarean sections.