title: Omega-shaped variant of the umbilical artery: prenatal diagnosis and outcome.
abstract: The purpose of this series was to report on the observation of an anomalous course of the umbilical artery. Ten cases in a 25-month period are reported. An omega-shaped variant, coined the "omega sign," of one of two umbilical arteries or of a single umbilical artery was observed. In 2 cases, there were two umbilical arteries, one of them with the anomalous vessel. In 8 cases, the vessel was a single umbilical artery. In 1 case with a single umbilical artery and pericardial effusion, aneuploidy was found on amniocentesis. A second case was associated with multiple anomalies. A third case was associated with hypoplastic left heart syndrome. Seven cases with the omega sign as an isolated finding, with or without a single umbilical artery, had favorable outcomes. An omega-shaped variant of the umbilical artery is likely to be more common in cases of a single umbilical artery than in cases with two umbilical arteries. It is probably a normal variant when unassociated with additional sonographically detectable structural anomalies.
authors: Department of Obstetrics and Gynecology, Shaare Zedek Medical Center, Jerusalem, Israel. orishen@netvision.net.il
authors: Ori
authors: O
authors: Shen
authors: Ron
authors: R
authors: Rabinowitz
authors: Gustavo
authors: G
authors: Malinger
authors: Eyal
authors: E
authors: Mazaki
authors: Avi
authors: A
authors: Tsafrir
mesh_terms: D000015:Abnormalities, Multiple / Q000000981:diagnostic imaging* / Q000196:embryology*; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods*; D014469:Umbilical Arteries / Q000002:abnormalities* / Q000000981:diagnostic imaging*