Continuous fetal intrapartum monitoring in supraventricular tachycardia by atraumatic measurement of transcutaneous carbon dioxide tension.

A case of premature beats and paroxysmal supraventricular tachycardia without resulting congestive heart failure was diagnosed in a fetus of 38 weeks of gestation by echocardiography. Transplacental antiarrhythmic therapy was initiated, but a complete cardioversion was not achieved. Due to these arrhythmias adequate fetal heart rate monitoring during labor was not possible. By using continuous transcutaneous measurement of fetal carbon dioxide tension the fetus was delivered spontaneously, having been adequately monitored in spite of the effect on the fetal heart rate of the arrhythmias.