389: Fetal tachyarrhythmias: the comparison between cases with or without intrauterine treatment: a retrospective data analysis in Japanese population


      Although the Fetal therapy(Ftx) for fetal tachycarrhythmias (FT) is now performed relatively often recently, the management of FT has not been standardized because of limited data on how Ftx affects the clinical course. The aim of this study was 1) to review the efficacy and safety of Ftx using the data on Japanese population and 2) to determine the impact of FTx on the FT natural history.

      Study Design

      Data for 2004 to 2007 on fetuses with sustained FT were obtained from 750 Japanese perinatal care institutes.Cases were classified as supraventricular tachycardia (SVT), atrial flutter, ventrivcular tachycardia and others. Data on fetal diagnosis, the presence of fetal hydrops (FH), associated anomalies and Ftx (the types of antiarrhythmic agents, efficacy and side effects) were collected. Presence of neonatal tachycardia, gestational ages, delivery mode, neonatal management and outcome were also analysed. All cases were categorized into groups with or without Ftx and compared obstetrical and neonatal prognoses.


      82 cases (14 FH) were analyzed. SVT was the most common fetal diagnosis (n=44). Ftx was performed for 41 using various agents(digoxin, flecainide and sotalol). The data showed high overall efficacy for FT and FT with FH (92.7% and 82.7%). 3 death cases were reported. As shown in thetable, treated cases showed significantly lower incidence of preterm birth, cesarean-section and neonatal tachycardia.


      Ftx has successfully improved FT, even for the cases with HF. This nation-wide retrospective data analysis confirms that FTx has beneficial effects on the clinical course of FT. The main benefit of Ftx is a reduced incidence of premature birth, cesarean section and neonatal arrhythmias.
      Tabled 1Fetal tachycardia with/without fetal therapy(*P<0.05).
      Ftx (%)non-Ftx (%)
      hydrops11 (26.8)3 (7.3)
      cesarean section12 (29.3)*29 (70.7)*
      preterm5 (12.2)*17 (41.5)*
      neonatal tachycardia20 (48.8)*32 (78)*
      death1 (2.4)2 (4.9)