Umbilical artery aneurysm in a severe growth-restricted fetus with normal karyotype

Umbilical artery aneurysm without aneuploidy and delivery of a live neonate

Objectives

Umbilical artery aneurysm, a rare structural anomaly of the umbilical cord, is frequently associated with fetal aneuploidy, fetal growth restriction and fetal demise. At present there are no definitive protocols or guidelines for the surveillance and management of this condition.

Case presentation

The index case is an 18-year-old primigravida who had an ultrasound at 35 weeks and 5 days gestation due to lagging symphysio-fundal height measurement. The ultrasound scan revealed a normal fetus with estimated fetal weight that was appropriate for gestational age. There was a cystic structure with internal echoes originating from the placenta at the point of the umbilical cord insertion, which was determined to be a 1.9 × 1.8 cm umbilical artery aneurysm on 3D and Doppler imaging. On follow up imaging the aneurysm had increased in size and measured 3.06 × 1.79 cm. The patient subsequently had a cesarean section delivery of a live female. Karyotyping subsequently revealed 46 XX.

Conclusions

A total of 15 cases of umbilical artery aneurysm have been reported in the literature to date, of which there were 5 live born infants with normal karyotype. The remaining 10 cases were intra-uterine fetal demise or trisomy 18 with subsequent neonatal deaths. When monitoring the aneurysms with ultrasound, change in size and Doppler indices play a pivotal role in helping to determine time and mode of delivery and thus allow for a favorable perinatal outcome.

Current Perspectives of Prenatal Sonography of Umbilical Cord Morphology

The umbilical cord constitutes a continuation of the fetal cardiovascular system anatomically bridging between the placenta and the fetus. This structure, critical in human development, enables mobility of the developing fetus within the gestational sac in contrast to the placenta, which is anchored to the uterine wall. The umbilical cord is protected by unique, robust anatomical features, which include: length of the umbilical cord, Wharton’s jelly, two umbilical arteries, coiling, and suspension in amniotic fluid. These features all contribute to protect and buffer this essential structure from potential detrimental twisting, shearing, torsion, and compression forces throughout gestation, and specifically during labor and delivery. The arterial components of the umbilical cord are further protected by the presence of Hyrtl’s anastomosis between the two respective umbilical arteries. Abnormalities of the umbilical cord are uncommon yet include excessively long or short cords, hyper or hypocoiling, cysts, single umbilical artery, supernumerary vessels, rarely an absent umbilical cord, stricture, furcate and velamentous insertions (including vasa previa), umbilical vein and arterial thrombosis, umbilical artery aneurysm, hematomas, and tumors (including hemangioma angiomyxoma and teratoma). This commentary will address current perspectives of prenatal sonography of the umbilical cord, including structural anomalies and the potential impact of future imaging technologies.

Prenatal Diagnosis of Umbilical Artery Aneurysm with Good Fetal Outcome and Review of Literature

Umbilical artery aneurysm is a rare condition. Till date, 14 cases are reported and only 4 had good fetal outcome. Umbilical artery aneurysm is associated with high risk of fetal aneuploidy and fetal demise. Though umbilical cord anomalies are rare, they are associated with significant fetal morbidity and mortality. We report a case of umbilical artery aneurysm which was detected at 33 weeks of gestation on ultrasonography as an anechoic cyst close to cord insertion with turbulent blood flow in it. The patient was hospitalized and with intensive fetal surveillance and early delivery, a live born fetus was achieved. Baby's karyotype was normal. Pathologic examination confirmed umbilical artery aneurysm close to cord insertion.

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.

Large umbilical artery aneurysm with a live healthy baby delivered at 31 weeks

Umbilical artery aneurysm is a rare structural anomaly. We report a case of a large cord mass monitored closely with MCA PSV aiding the decision for delivery in an appropriately grown fetus.