Perinatal outcomes in isolated single umbilical artery.

We sought to determine the rate of adverse perinatal outcomes in pregnancies diagnosed with an isolated single umbilical artery (SUA). We performed a retrospective review comparing 68 pregnancies with an isolated SUA to 68 pregnancies with a three-vessel cord (3VC). Pregnancies with structural or karyotypic anomalies were excluded. Gestational age at delivery, birth weight, SGA rate, ponderal index, and rates of admission to the neonatal intensive care unit were compared between groups. Student T test and chi-square analysis were performed. Neonates with isolated SUA had a significantly smaller birth weight than those with a 3VC (3279 +/- 404 g versus 3423 +/- 374 g, P = 0.0168). There was no significant difference in rates of SGA (17.6% versus 8.8%, P = 0.06). Ponderal index was significantly less in those with SUA compared with 3VC (24.2 +/- 1.1 g/cm(3) versus 26.1 +/- 1.3 g/cm(3), P = 0.001). SUA neonates had a significantly longer length of neonatal intensive care unit stay than 3VC neonates (1.25 +/- 2.2 days versus 0.48 +/- 1.25 days, P < 0.023). Fetuses with a prenatal diagnosis of isolated umbilical artery have a significantly lower ponderal index compared with fetuses with a 3VC. Pregnancies with isolated SUA should undergo serial assessments for fetal growth. Thieme Medical Publishers.