Prenatal Ultrasound in Fetal Inferior Vena Cava Abnormalities: Image Characteristics and Clinical Relevance

Abstract

Background: During the embryonic stage, the inferior vena cava (IVC) is an important conduit for the hepatic vein and ductus venosus to drain into the right atrium. For fetuses with IVC abnormalities, the prognosis may be favorable if the condition is not complicated with other malformations, but would be poor if atrial isomerism coexists. In severe cases, edema, intrauterine fetal death, and atrioventricular block may occur. Therefore, comprehensive prenatal ultrasound that provides detailed information about IVC abnormalities may be clinically significant. Methods: A total of 180 fetuses diagnosed with IVC anomalies via prenatal ultrasound at Hospital of Chengdu University of Traditional Chinese Medicine and Sichuan Provincial Maternity and Child Health Care Hospital from January, 2017 to December, 2022 were included in this study. Their ultrasound image characteristics, associated intra- or extracardiac malformations and pregnancy outcomes were retrospectively analyzed. Results: Among the 180 fetuses, 59 cases were diagnosed with interrupted IVC (53 cases with the interruption of the hepatic segment of the right IVC and 6 cases with the interruption of the entire right IVC), 1 case was diagnosed with the stenosis of the hepatic segment of the right IVC, 90 cases were diagnosed with left sided IVC, 29 cases with double IVC, and 1 case with abnormal connection of the IVC to the left atrium. Moreover, 33 cases had intracardiac malformations and 36 cases had extracardiac malformations. Pregnancy outcomes: 160 fetuses were live born, and their prenatal ultrasound diagnoses were confirmed by computed tomography (CT)/magnetic resonance imaging (MRI) or surgery; the remaining 20 fetuses were terminated due to serious malformations, and their prenatal ultrasound diagnoses were confirmed by pathologic examination. Conclusions: Prenatal ultrasound can clearly reveal the fetal IVC abnormalities and the associated intra- or extracardiac malformations. For suspected cases, attention should be focused on prenatal ultrasound examinations in order to obtain valuable information for prenatal consultation and subsequent procedures and care.