Fetal isolated prominent left brachiocepalic vein: in utero natural history and neonatal outcome.

The objectives of this series were to describe the prenatal sonographic findings of a fetal isolated prominent left brachiocephalic vein with its in utero natural history and neonatal outcome and to discuss the differential diagnosis, especially with a total or partial anomalous pulmonary venous return malformation. We reviewed all cases referred to 2 tertiary medical centers with the presenting finding of a prominent, upper thorax transverse vein entering the superior vena cava. The primary suspicion of a subjective dilated left brachiocephalic vein, as a part of a supracardiac anomalous pulmonary venous return malformation, was investigated by a systematic anatomic evaluation. After exclusion of other cardiac and structural anomalies, we followed the pregnancies and their outcomes. Eight cases were recruited during a 7 year period. The mean maternal age was 31 years, and the mean gestational age at the time of diagnosis was 17 weeks. In 7 cases, the dilatation was not evident during 6 weeks of follow up. In 1 case, the dilatation was evident until delivery at 39 weeks and was not apparent on postnatal echocardiography or spiral computed tomography. All neonates developed without any heart or other complications. We conclude that after exclusion other malformations, a prominent left brachiocephalic vein is a benign transient phenomenon that does not persist post-partum in the neonate.