Background: The presence of a single umbilical artery (SUA) is a fetal soft marker of congenital abnormalities. Among the most common related malformations, there are cardiological, nephrourological and digestive anomalies, most of which are considered to have a vascular etiology. There is an association between increased incidence of intrauterine growth retardation and adverse perinatal indicators, but whether this association is due to related anomalies or isolated SUA (iSUA) is controvisal.
Methods: We reviewed 96 cases of iSUA and non-isolated SUA (niSUA), diagnosed in a period of two years in a referral hospital for high-risk pregnancies. Data on prenatal explorations, including fetal ultrasonography and karyotyping, were obtained. niSUA was diagnosed when no malformations were found prenatally or in postnatal evaluation.
Results: Sixty-six newborns (68.8%) had no other anomalies and 30 (31.3%) presented with a variety of malformations including heart diseases, urophaties, digestive, nervous and musculoskeletal disorders, genetic abnormalities and complex malformations. Cardiological and nephrourological abnormalities were found to be the most frequent association with a SUA (both in 23.8% of malformed SUA newborns). Intrauterine growth restriction was not higher in iSUA newborns than in a normal population. Ultrasound allowed optimal prenatal diagnosis in most cases.
Conclusions: The prognosis of the fetus with a SUA is determined by the presence of other malformations observed by an expert sonographer. If no other findings are made, only a routine physical examination should be performed in newborns, but no other complementary examinations are required.