Outcomes following prenatal diagnosis of isolated persistent left superior vena cava

Background: Prenatal diagnosis of persistent left superior vena cava is increasing, but little is known about outcomes of infants with prenatally diagnosed isolated persistent left superior vena cava.

Objective: To assess the outcomes of infants with isolated persistent left superior vena cava diagnosed prenatally compared with infants with associated malformations.

Methods: All cases of persistent left superior vena cava confirmed by specialized fetal echocardiography in pregnant women were included from a single-centre prospective registry. Unfavourable outcome was defined as termination of pregnancy, in utero death, postnatal death or severe genetic syndrome missed prenatally.

Results: A total of 256 infants were included: 113 cases (44.1%) with isolated persistent left superior vena cava and 143 cases (55.9%) with associated malformations; respectively, 111 (98.2%) and 101 (70.6%) had a live birth. The median postnatal clinical follow-up was 3.6 years. Five-year postnatal survival with good outcome was estimated at: 100% (95% confidence interval 90.7% to 100%) in infants with isolated persistent left superior vena cava; 91.0% (74.0% to 98.1%) in infants with associated cardiac anomalies; 87.5% (51.8% to 97.3%) in infants with associated extracardiac anomalies; 81.0% (52.6 to 94.6%) in infants with both cardiac and extracardiac anomalies; and 78.9% (36.7% to 95.9%) in infants with non-structural anomalies. All genetic findings and syndromes were detected in fetuses or infants with non-isolated persistent left superior vena cava.

Conclusion: Infants with isolated persistent left superior vena cava have good short-term outcomes postnatally, but persistent left superior vena cava is frequently associated with other malformations that have an effect on outcomes, which should be thoroughly searched for prenatally.