Sonographic Findings in Fetal Renal Vein Thrombosis

We present the sonographic findings of fetal renal vein thrombosis in a series of 6 patients. The mean gestational age at diagnosis was 31.2 weeks. Four cases were unilateral, and 2 were bilateral. The most common findings were renal enlargement and intrarenal vascular calcifications, followed by increased renal parenchymal echogenicity. Inferior vena cava thrombosis was found in 4 patients and common iliac vein thrombosis in 2. Fetal renal vein thrombosis is an uncommon diagnosis with characteristic sonographic findings. The presence of these findings should prompt Doppler interrogation of the renal vein and inferior vena cava to confirm the diagnosis.