Prenatal Management of Fetal Paroxysmal Tachycardia Complicated by Fetal Hydrops

Abstract

Background: The rate of fetal tachycardia is approximately 0.5% of all pregnancies and it is an important cause of fetal morbidity and mortality. CASE REPORT: A 33-year-old woman, gravida III, presented at 37 weeks of gestation due to the lack of fetal movements. She had vaginal delivery and miscarriage in anamnesis. At 34 weeks of gestation fetal paroxysmal tachycardia 300 bmp, fetal hydrops, ascites, pericardial effusion and heart failure (HF) were detected. Treatment with intravenous propafenone 140 mg was started, fetal heart rate (HR) was normal for several hours, but atrial flutter was monitored 5 hours later. Additional doses of propafenone 150 mg and metoprolol 50 mg were given orally. There was no therapeutic effect, mother refused emergency c-section and further cardiological treatment. Next day echoscopy showed no movements, fetal HR was 307 bpm. Intravenous digoxin 0.25 mg was initiated, the dose was repeated 2 hours later. Fetus vital functions after 9 hours: HR 142-144 bpm, normal heart rhythm, HF and hydrops disappeared, umbilical and brain circulation normal. Mother's vital functions remained stable. She was discharged. Further treatment with oral digoxin 0.25 mg a day and sotalol 80 mg twice a day until the end of pregnancy was prescribed. After readmission she was monitored in the ICU and got additional intravenous digoxin 0.25 mg with verapamil 40 mg and oral sotalol 80 mg. Despite this treatment fetal state was deteriorating. Caesarean section under spinal anesthesia was performed. Hemodynamics of mother remained stable. Newborn's APGAR scores of 1st and 5th minutes were 7 and 8 respectively. Conclusions: Fetal tachycardia has a high risk for developing low cardiac output, hydrops and sometimes fetal death or adverse neurological effect after birth. Digoxin is an antiarrhythmic drug which has a positive inotropic effect and could be safe to use when HF occurs. Sotalol is often added while treating with digoxin, because digoxin alone is poorly transferred to the fetus in the presence of hydrops and quicker control of arrhythmia is achieved. If the fetus is at term of delivery, emergency delivery and antiarrhythmic therapy must be provided to a newborn. If the fetus is nonhydropic, vaginal delivery can be taken into the consideration.