Antenatal Detection of Single Umbilical Artery and Subsequent Pregnancy Outcome
Aim: To evaluate pregnancy outcomes following detection of a single umbilical artery (SUA), in isolation and together with other anomalies.
Methods: All fetuses with SUA seen on antenatal ultrasound in the Medical Imaging Department at Mercy Hospital for Women in Victoria between 1995 and 2002 were identified. Obstetric, ultrasound, pediatric and histopathology records were reviewed. Only fetuses with SUA confirmed by visual inspection of the umbilical cord at delivery or histopathological examination were included.
Results: Eighty two fetuses met the study criteria. SUA was seen on ultrasound as an isolated finding in 61 fetuses (74.4%) and with other anomalies in 21 (25.6%). Eight (13.1%) of the 61 fetuses with apparently isolated SUA had additional anomalies although the majority of these were minor in nature or would not have been seen or reliably seen on ultrasound. There were no chromosomal abnormalities in fetuses with SUA alone or together with minor markers. At least one in 4 SUA fetuses with a major malformation had aneuploidy. SUA fetuses with major malformations tended to have lower mean gestations and weights at delivery as well as significantly increased low birth weight, preterm delivery, aneuploidy and perinatal mortality rates compared to fetuses with isolated SUA.
Conclusions: SUA may be complicated by congenital anomalies and poor pregnancy outcomes. These outcomes are worse for SUA fetuses with major malformations than for isolated SUA. The finding of a SUA on ultrasound necessitates a detailed search for other anomalies. Karyotyping should be offered for SUA fetuses with a major anomaly.