Introduction: Diagnosis and management of fetal thrombosis during pregnancy is rare. Few cases of prenatally diagnosed inferior vena cava thrombi are reported and often occur with renal vein thrombi. Several maternal and fetal risk factors have been identified, including thrombophilias. Case Report: Patient is a 39-year-old G6P2123 with heterozygous Factor V Leiden with a prenatally diagnosed fetal inferior vena cava thrombus at 34 weeks of gestation during antenatal ultrasound. Her peripartum course was uncomplicated. On day 1 of life, neonatal ultrasound and computed tomography confirmed the presence of thrombus. On day 7, the neonate underwent a thrombectomy for definitive management due to risk of embolization. Conclusion: While ultrasound is not routinely used for screening for fetal thromboses, when thrombosis is diagnosed, antenatal management is complex, weighing fetal and maternal risks and benefits. Thrombectomy as definitive thrombus management is an appropriate treatment when risk of embolization exists. Imaging modalities are useful for both diagnosis and management of fetal thrombi.