Single umbilical artery is a developmental anomoly which may be noted on inspection of the cord after birth. It may be an isolated finding, but may indicate more further underlying abnormalities, particularly in renal development, and ultrasound scanning is recommended to detect this.
A study has been undertaken to evaluate the perinatal outcome in fetuses with single umbilical artery detected on targeted prenatal ultrasound without other anomalies (1):
- an isolated single umbilical artery was suspected on prenatal ultrasound examination in 57 fetuses evaluated at two referral centers. Targeted imaging to rule out concurrent fetal anomalies was normal in all cases
- complete follow-up was available in 50 cases
- study results
- a two-vessel umbilical cord was confirmed at birth in 50 neonates
- mean gestational age at delivery was 38.6 ± 2.8 weeks; the mean birth weight was 3202.8 ± 835.8 g
- seventeen patients (34%) underwent genetic amnio-centesis, and all fetuses had a normal karyotype
- one neonate ascertained to have a congenital anomaly after birth was diagnosed with total anomalous pulmonary venous return
- there were no perinatal deaths
- the authors concluded that, in the absence of additional sonographically detectable anomalies, an isolated single umbilical artery does not seem to affect clinical outcome and therefore should not alter routine obstetric management
- Parilla BV et al. The clinical significance of a single umbilical artery as an isolated finding on prenatal ultrasound. Obstet Gynecol. 1995 Apr;85(4):570-2.