EP17.32: Isolated single umbilical artery and risk of adverse perinatal outcome

Single umbilical artery (SUA) is considered to be an ultrasound marker of anomalies. Though it may be present in up to 5% of normal pregnancies, it has been reported to be associated with an increased risk for intrauterine growth retardation, cardiac, genitourinary and gastrointestinal malformations and chromosomal abnormalities such as Trisomy 21 and 18. The aim of this study was to check, based on clinical data collected from pregnant women attended in the Salamanca Healthcare Area, whether the presence of isolated UAU is related to adverse perinatal outcomes. This is a descriptive, observational and retrospective study in which 1267 single gestations were evaluated. Only cases of isolated UAU were included. Cases in which UAU was associated with another pathology or fetal malformation were excluded. The presence of isolated SUA was associated with lower gestational age (38 vs 39 weeks), lower birthweight (3181 vs 3013 g), higher rate of Caesarean section and instrumental delivery. No differences were found in Apgar test scores, pH at birth, admissions to the neonatal ICU, increase in malformations or genetic disorders. Isolated SUA is associated with a lower gestational age and birthweight and with a greater number of labour inductions, instrumental delivery and Caesarean sections. Though isolated SUA is considered to be a marker of genetic conditions, no genetic disorders were found in our series.