AbstractHereditary Hemorrhagic Telangiectasia (HHT), commonly known as Osler–Weber–Rendu disease, is an autosomal dominant multisystemic vascular disease associated with approximately 70% of cases of pulmonary arteriovenous malformations (PAVMs). Prenatal cases of PAVMs typically present with pulmonary vein dilatation on ultrasonography. This study presents a prenatal diagnosis of PAVMs with enlarged right pulmonary vein, cardiomegaly, cystic‐appearing areas in the right lung and subsequent confirmation of Osler–Weber–Rendu syndrome using autopsy and whole exom sequencing.