To evaluate the clinical utility of echocardiography in the prenatal diagnosis of fetal persistent left superior vena cava (PLSVC) with absent right superior vena cava (RSVC).

A retrospective analysis was conducted on the echocardiographic features of 43 fetal cases diagnosed with PLSVC and absent RSVC at Chongqing Health Center for Women and Children from November 2016 and December 2024. Associated genetic testing results were also reviewed and analyzed.

Among the 43 cases included, 24 (24/43, 55.81%) were identified as having isolated PLSVC with absent RSVC, 8 (8/43, 18.60%) were associated with additional intracardiac structural anomalies, and 11 (11/43, 25.58%) exhibited both intracardiac and extracardiac malformations. Genetic testing was performed in 32 cases (32/43, 74.42%), of which 30 (30/32, 93.75%) had normal findings. Pregnancy outcomes included 27 live births (27/43, 62.79%) and 12 terminations (12/43, 27.91%). Among the live-born cases, 24 were diagnosed with isolated PLSVC with absent RSVC. Echoardiographic features of isolated PLSVC with absent RSVC included absence of the RSVC, visualization of the left superior vena cava draining into the right atrium via the coronary sinus, and reversed flow from the innominate vein into the left superior vena cava. Three cases were associated with additional structural anomalies. Prenatal ultrasound findings in these three cases included muscular ventricular septal defect, a slightly enlarged left heart compared to the right, and partial atrioventricular septal defect.

Fetal echocardiography is an important method for detecting PLSVC with an absent RSVC and holds significant clinical application value. Fetuses presenting with isolated PLSVC and absent RSVC generally have favorable postnatal outcomes.