Clinical presentation, genetic etiologies and outcomes associated with fetal cardiomyopathies in a more recent era

OBJECTIVES To assess rates and types of genetic diagnoses and clinical outcomes in fetal cardiomyopathy (CM) over two eras to examine the impact of advanced genetic testing and improved perinatal management strategies. METHODS We retrospectively reviewed all diagnoses of fetal CM in Alberta, Canada encountered from 2003-2019. Genetic, cardiac and non-cardiac diagnoses were documented, as were clinical outcomes. Comparisons were made between the earlier (2003-2012) and later (2013-2019) eras. Cases with CM secondary to extracardiac pathologies and maternal conditions were excluded. RESULTS Thirty-eight cases met the inclusion criteria and were diagnosed at a median gestational age (GA) of 22.8 (13.4-37.4) weeks. There was associated structural heart disease in 40% (15/38) and 24% (9/38) had arrhythmias. Hydrops was identified in 29% (11/38) at presentation, and a further 18% (7/38) evolved hydrops. Twenty-six % (10/38) underwent termination of pregnancy, and 24% (9/38) had intra-uterine death. Of livebirths, 16% (3/19) had a neonatal death and 63% (12/19) were alive at last follow-up. Excluding cases with termination of pregnancy, a higher proportion survived through the neonatal period in the later era (65%, 11/17 vs 46%, 5/11) although this was not statistically significant (p=0.44). A genetic etiology was confirmed in 40% (15/38) and suspected in 24% (9/38). A higher proportion had a confirmed or suspected genetic etiology in the current era (76%, 19/25 vs 39%, 5/13, p=0.04). CONCLUSIONS In the current era, a higher proportion of fetal CM cases have a confirmed or suspected genetic etiology than previously reported. Compared with older series, modern perinatal management strategies may not have a significant impact on neonatal survival for fetal CM; however, a larger study would be better powered to detect more subtle differences. This article is protected by copyright. All rights reserved.