Prenatal Predictors of Fetal and Neonatal Death in Truncus Arteriosus: A Fetal Heart Society Research Collaborative...

Fetal and neonatal outcomes and factors increasing mortality risk in fetal truncus arteriosus are not well characterized. We aimed to examine the prenatally encountered cardiac spectrum, define extracardiac and genetic associations, explore clinical outcomes and identify prenatal factors associated with worse outcomes in a contemporary large cohort.

A multicenter retrospective cohort study was conducted via the Fetal Heart Society Research Collaborative including fetal truncus arteriosus cases encountered between January 1, 2010, and September 1, 2021, within 22 North American cardiac centers. Demographic, clinical, anatomic, and functional fetal echocardiographic variables were analyzed for associations with presurgical death (fetal death/neonatal presurgical death/neonatal listing for heart transplantation before initial hospital discharge). Variables were compared between survivors and nonsurvivors with nonparametric tests and univariable logistic regression; a multivariable linear probability model was used for further assessment after adjusting for confounders.

Of 378 fetuses diagnosed prenatally, 201 (53.2%) had a genetic abnormality or extracardiac anomaly identified. Pregnancy termination was chosen in 47 (12.4%) pregnancies and palliative care in 13 (3.4%). Of 318 pregnancies with intention to treat, 17 (5.3%) ended in fetal death and 19 (6%) in neonatal presurgical death. In addition to prematurity and low birth weight, truncal valve stenosis (but not regurgitation or anatomic subtype) and ventricular dysfunction were associated with presurgical death.

Half of fetuses with truncus arteriosus will have an associated genetic abnormality or extracardiac anomaly. Truncal valve stenosis and ventricular dysfunction, as well as preterm birth and low birth weight, are associated with presurgical death. These data are important for prognostication and prenatal counseling.