Fetal atrial flutter is a condition with a macroreentry circuit confined and originated in the right atrium with a rapid regular atrial rate of 300–600 beats/min associated to different degrees of atrioventricular block with slower ventricular rates. Digoxin and Sotalol are the election treatment. A 33 years old woman with 32 weeks of gestational age and gestational diabetes condition was sended to our hospital. Level II scan reported atrial rates in 440 beats/min and ventricular rates of in 220 beats/min. Cardiac output in LV was 959 ml/min with EF% in 51,6. No structural anomalies were noted in routine fetal echocardiogram. Sotalol 160 mg two times at day was started. Fetal rate returned to sinus rhythm occasional. Cardiac output was reported 313 ml/min with an EF% 41. We increased doses three times daily. Fetal atrial flutter persisted for 2 weeks more. We added digoxin 0.1 mg at three times daily for two days and after that 0.1 mg ones at day. The fetal ventricular rates go back to normal rate in 72 hours (140 with conduction 1 : 1). Cardiac output in LV was 491 ml/min and EF% 46.4. No heart failure in fetuses was reported. Middle cerebral artery had absent diastole until sinus rhythm was established again. The fetuses was delivery at 37 weeks by Cesarean section with normal heart rate by electrocardiogram. Cardiologis found pulmonary hypertension. They started sotalol with out any complication. Cardiac output is correlated with fetal heart rate. Atrial flutter increase cardiac output but EF% remains normal. Atrial flutter decrease diastole flow in middle cerebral artery. Atrial flutter with out treatment could be correlated with high cardiac output failure and neurological outcome compromise. Sotalol could be the election treatment associated with digoxin. Digoxin have synergism with sotalol. With out hydrops the delivery time has to be after 37 weeks. No mother effects were noted. More data needs to be collected.