THE CLINICAL-SIGNIFICANCE OF A SINGLE UMBILICAL ARTERY AS AN ISOLATEDFINDING ON PRENATAL ULTRASOUND

Objective: To evaluate the perinatal outcome in fetuses with single um bilical artery detected on targeted prenatal ultrasound without other anomalies. Methods: During a 3.5-year period, an isolated single umbil ical artery was suspected on prenatal ultrasound examination in 57 fet uses evaluated at two referral centers. Targeted imaging to rule out c oncurrent fetal anomalies was normal in all cases. Pregnancy and perin atal outcome data were retrieved by review of the medical records or f rom conversations with referring physicians. Complete follow-up was av ailable in 50 cases. Results: A two-vessel umbilical cord was confirme d at birth in 50 neonates. The mean gestational age at delivery was 38 .6 +/- 2.8 weeks; the mean birth weight was 3202.8 +/- 835.8 g. Sevent een patients (34%) underwent genetic amniocentesis and all fetuses had a normal karyotype. The only neonate ascertained to have a congenital anomaly after birth was diagnosed with total anomalous pulmonary veno us return. This neonate underwent a corrective surgical procedure and is thriving with no apparent problems at 3.5 years of age. There were no perinatal deaths. Conclusion: In the absence of additional sonograp hically detectable anomalies, an isolated single umbilical artery does not seem to affect clinical outcome and therefore should not alter ro utine obstetric management.