New Drugs and Technologies Current Status of Fetal Cardiac Intervention

The potential benefits of fetal cardiac intervention (FCI) have been realized for many years. In 1975, Eibschitz et al1 reported intrapartum treatment of fetal ventricular tachycardia by administering propranolol to the mother, and as early as 1986, in utero pacing was attempted for complete heart block in a human fetus.2 Recently, however, interest in FCI has accelerated.3–18 As with other fetal interventions,19,20 FCI can only become a highly useful clinical tool if it is applied to conditions in which a feasible mode of therapy is available and either the fetus is at risk for demise as a result of the condition or intervention may alter the evolution of the condition such that the severity of the postnatal disease is substantially reduced (Table 1). For conditions in which the fetus is at high risk for prenatal or neonatal death, the rationale for FCI is obvious, to improve survival. If death is not imminent but the disease is likely to have major lifelong morbidity, the rationale is that FCI will modify the course of cardiac growth, function, and/or development in utero sufficiently to alter postnatal outcome and justify the potential risks of the procedure. Prenatal intervention may also allow the fetus to recover in the supportive in utero environment, during a developmental period when there is enhanced wound healing and the capacity for myocyte proliferation.21,22 This construct rightfully emphasizes death or significant morbidity as therapeutic targets. FCI can entail substantial short-term risk to the fetus, uncertain long-term risk to the fetus and child, and at least some risk to the mother. There are no known medical benefits to the mother. With that risk profile, FCI will not be embraced by the maternal-fetal medicine and cardiology communities unless it is used to treat serious conditions in which the potential benefits to the fetus are high and can be achieved in a reasonable percentage of cases. Although many recent publications have dealt with closed, “minimally invasive” FCI, there is a considerable body of evidence regarding pharmacological and surgical FCI as well. This review will touch on all of these topics, with a focus on the most recent literature.