Severe fetal anemia as a consequence of extra‐abdominal umbilical vein varix: A case report and review of the literature

Abstract

Umbilical vein varix is associated with a high incidence of fetal anomalies and perinatal complications. There are two types of umbilical vein varix: fetal intra-abdominal and extra-abdominal. Herein, a case is reported of severe fetal anemia with extraabdominal umbilical vein varix. A 33-year-old primigravida was referred to our hospital for fetal growth restriction, fetal cardiomegaly, and decreased fetal movements at 26 weeks' gestation. A Doppler assessment showed an elevated middle cerebral artery peak systolic velocity at 2.2 MoM, suggesting fetal anemia. Umbilical vein varix had caused intermittent turbulent flow, provoking hemolytic anemia. Intrauterine transfusion improved fetal circulatory failure and anemia and prolonged gestational period. At 33 weeks' gestation, the patient underwent cesarean delivery due to nonreassuring fetal status. Pathological analysis revealed focal loss of vascular smooth muscle of the umbilical vein. Extra-abdominal umbilical vein varix has been reported in 14 cases including this case. The antenatal diagnosis rate is reported to be 79%; fetal heartbeat abnormalities and fetal deaths were reported as 50% and 14%, respectively. Eighty-six percent of patients had intra-umbilical cord thrombosis, but currently this is the only case of hemolytic anemia. Furthermore, extra-abdominal umbilical vein varix may present as fetal hydrops with anemia. During ultrasound examination of fetal anemia, umbilical cord screening should be performed with caution.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

“…Umbilical varix is defined when the caliber is greater than 9 mm or with a ratio of >50% between the dilated and a more distal normal intraabdominal portion of the vein (Figure 8). [180][181][182] The incidence of this condition is relatively rare, occurring between 0.4 and 1.1/1000 deliveries and is associated with additional fetal anomalies in one-third of cases, [183][184][185]…”

Current Perspectives on Umbilical Cord Abnormalities Including Blood Flow Parameters Based on Ultrasound Observations

“…UVV is generally limited to one segment and has a different length. Compared with the intra-amniotic UVV, the intra-abdominal UVV have a higher probability of chromosomal abnormalities [34,35]. Excluding chromosomal abnormalities and fetal structural abnormalities, the prognosis of intra-abdominal UVV is favorable, and the probability of serious complications is not high [34,35].…”

“…The umbilical vein varix (UVV) is relatively rare, with an overall incidence of 0.4%-1.1% [33][34][35][36]. Dilatation of the umbilical vein in the abdominal cavity of the fetus, known as intra-abdominal umbilical vein varix (Fig.…”

“…Compared with the intra-amniotic UVV, the intra-abdominal UVV have a higher probability of chromosomal abnormalities [34,35]. Excluding chromosomal abnormalities and fetal structural abnormalities, the prognosis of intra-abdominal UVV is favorable, and the probability of serious complications is not high [34,35]. The extra-abdominal UVV is associated with fetal thrombosis, hematoma, obstruction of umbilical artery compression, and perinatal death [34,35].…”

Telemedical monitoring of a high-risk pregnancy with placental cyst in times of Corona: A case report

“…Extra-abdominal umbilical vein varices are extremely rare fetal vascular anomalies. They are associated with adverse fetal outcome such as fetal anemia, fetal heart failure and hydrops fetalis or fetal death [6,7].…”