Tetralogy of Fallot in the fetus - from diagnosis to delivery. 18-year experience of a tertiary Fetal Cardiology Center

Tetralogy of Fallot (TOF) is a common congenital heart disease but very heterogeneous in terms of detailed cardiac anatomy, associated malformations, and genetic anomalies, especially when assessed prenatally.We aimed to analyze the clinical spectrum of TOF in the prenatal period, including detailed cardiac morphology, coexisting anomalies, and their impact on short-term neonatal outcome. We also assessed changing trends in the prenatal diagnostic workup of TOF.A retrospective cohort study including fetuses diagnosed with TOF between 2002 and 2019 was conducted in a tertiary Fetal Cardiology Center. Medical records and echocardiographic examinations were reviewed to collect demographic, sonographic, and genetic data.Among 326 TOF fetuses, 237 (73%) had pulmonary stenosis (TOF-PS), 72 (22%) pulmonary atresia (TOF-PA), and 17 (5%) absent pulmonary valve (TOF-APV). The yearly number of diagnoses increased during the study period, with decreasing fetal age at the time of diagnosis. Extracardiac malformations were found in 172 (53%) fetuses, cardiovascular malformations in 159 (49%), and genetic anomalies in 99 (39% of the tested group). Hypoplastic thymus, right aortic arch, and polyhydramnios were sonographic markers of microdeletion 22q11. Left-to-right ductal flow was predictive of postnatal ductal dependency. The perinatal outcome was dependent on the presence of associated anomalies and disease subtype, with TOF-APV having the worst prognosis.Extracardiac and genetic anomalies are common in fetuses with TOF, and, together with disease subtype and ductal flow assessment, they impact the perinatal management and outcomes. Genetic testing with array comparative genomic hybridization should be offered in all cases.