Bovine aortic arch: Prevalence in human fetuses.

ABSTRACT

OBJECTIVE: "Bovine aortic arch" is the second most common variant of aortic arch branching, in which only two branches originate directly from the aorta. The prevalence of this condition has been reported in different studies to be around 6% in human fetuses and 11-27% in the adult population. In this study, we describe the prevalence of bovine aortic arch in fetuses, and assess the prevalence of concomitant fetal anomalies. METHODS: A retrospective analysis of 417 fetuses between 15-40 weeks of gestation. Data regarding branching of the fetal aortic arch and other fetal anomalies were collected by fetal echocardiography and/or fetal ultrasonography. RESULTS: A bovine arch was found in 20/413 fetuses (4.8%, 95CI 3.1-7.3%), of whom 14/310 (4.5%) had no fetal anomalies, and 6/77 (7.8%) exhibited minor changes (P = .241). None of the 26 fetuses with major anomalies had a bovine arch. CONCLUSION: Fetuses in this study had a lower prevalence of bovine aortic arch than that previously reported in adults, most probably due to differences in the population examined. This study was underpowered to determine that bovine arch is a common anatomic variant, and is not associated with fetal anomalies.