Derivation of analysis cohort. Among all subjects undergoing FAV for fetal aortic stenosis with high-risk features of evolving HLHS, those with technically unsuccessful procedures and/or fetal demise after FAV were excluded. The remaining 93 subjects were live-born after a technically successful FAV. Within this analysis cohort, 42 subjects (45%) achieved BiV circulation at neonatal discharge. Abbreviations: BiV (biventricular), FAV (fetal aortic valvuloplasty), HLHS (hypoplastic left heart syndrome), UV (univentricular)