Fetal bradycardia without fetal distress: case presentation and review of the literature.

A case of a term pregnancy with a persistent fetal heart rate of 65 to 80 beats/min is presented. Initially this was presumed to be due to congenital heart block. Subsequent fetal ECG revealed blocked atrial extrasystoles. Review of the literature showed 31 previously reported cases of heart block diagnosed in utero. A review of this literature is discussed and the importance of differentiating bradycardia due to heart block from bradycardia due to fetal distress is emphasized.