Abstract: Objective To explore the clinical characteristics,diagnosis and treatment of fetal intra-abdominal umbilical vein varix(FIUVV).Methods The clinical data and fetal outcomes of 22 pregnant women diagnosed with FIUVV by prenatal ultrasound in our hospital from January 2016 to December 2017 were retrospectively analyzed.Results Among FIUVV 22 cases,14 cases of simple FIUVV were eventually diagnosed as healthy infants after delivery. Other structural abnormalities were found in 8 cases,including enlargement of lateral ventricle in 3 cases,renal assembly system separation in 2 cases,racquet placenta in 1 case,widening of lateral ventricle with separation of renal collecting system in 1 case. All of the above cases were eventually diagnosed as healthy infants after delivery. Only 1 case with widening of septum pellucidum finally suffered fetal death in uterus. There was no chromosome abnormality in 22 cases of FIUVV.Conclusion Simple FIUVV has a good prognosis and other malformations can lead to poor pregnancy outcomes. Ultrasound is a good prenatal diagnosis method. When fetal intra-abdominal umbilical vein dilatation is found,it should be examined in detail and followed up regularly to prevent adverse consequences.