Umbilical artery aneurysm: a case report, literature review, and management recommendations.

BACKGROUND: Umbilical artery aneurysm is a rare and often lethal condition frequently associated with fetal anomalies, fetal demise, and neonatal complications. CASE: We report a case of umbilical artery aneurysm discovered at 21 weeks 2 days of gestation in a fetus of normal karyotype. Maternal hospitalization occurred at 28 weeks for antenatal testing, betamethasone administration, and monitoring for expansion of the aneurysm. Delivery of a live neonate by repeat cesarean delivery was performed at 32 weeks 2 days. Pathology confirmed a 3-vessel cord with an umbilical artery aneurysm. Neonatal course was complicated by respiratory distress of the newborn, hyperbilirubinemia, anemia, difficulty feeding, and cardiac defects. The newborn was discharged from the neonatal intensive care unit on day of life 19. CONCLUSIONS: Umbilical artery aneurysm is highly associated with fetal complications including trisomy 18, single umbilical artery, cardiac anomalies, and intrauterine fetal demise. A normal karyotype, antenatal monitoring, and early delivery have been suggested to impact the likeliness of survival. Antenatal management strategies include consideration of nonstress testing 3 times daily, serial ultrasound assessments, testing to identify intrauterine growth restriction, and delivery by planned cesarean delivery between 32 and 34 weeks. We recommend that patients be counseled on the high risks associated with umbilical artery aneurysm and be included in discussions regarding antenatal management and delivery planning.

The amniotic wrinkle: a pitfall in evaluating amniotic fluid for twins.

OBJECTIVE: The sonographic analysis of amniotic fluid in twin pregnancies can be complex and difficult, particularly when one twin has oligohydramnios or anhydramnios. This article describes a pitfall, the "amniotic wrinkle," which can lead to the erroneous impression that both twins have adequate fluid when one actually has little or none. METHODS: Sonograms of twin pregnancies in which the sonographer's initial assessment was of adequate fluid for each twin but imaging by the author on the same day showed one twin to have oligohydramnios were analyzed to identify recurring image patterns related to the intertwin membrane that may create this misleading impression. RESULTS: With oligohydramnios of one twin, the intertwin membrane may become redundant, folding on itself, creating an amniotic wrinkle: a short linear structure extending perpendicularly away from the twin with decreased amniotic fluid in toward the amniotic space of the other twin. A variation of this occurs when this fetus moves an extremity into the fold, with the two layers of the fold apposing each other between the limb and torso or between two limbs. An additional pattern is also described: an intrauterine sling or "cocoon" in which a fetus appears to be suspended within the amniotic space of the other twin. CONCLUSIONS: To avoid pitfalls in assessing amniotic fluid for twins, the intertwin membrane should be shown in every image that is used to document fluid ascribed to each twin, and images at right angles to the initial image can help identify an amniotic wrinkle.