Umbilical artery aneurysm: prenatal identification in three fetuses with trisomy 18

Color Doppler, HDlive, and HDlive Silhouette features of an umbilical cord cyst before 11 weeks of gestation: Diagnostic value

OBJECTIVE

We describe transvaginal color Doppler, HDlive, and HDlive Silhouette features of an umbilical cord cyst (UCC) before 11 weeks of gestation.

METHODS

In this cohort study, 135 transvaginal dating scans were performed at 7 to 10 + 6 weeks of gestation, and 17 UCCs were identified (12.6%). UCC was evaluated using color Doppler, HDlive, and HDlive Silhouette. The clinical characteristics, pregnancy courses, and outcomes were also investigated.

RESULTS

UCC location was on the fetal side in six cases, at the free loop in 10 cases, and on the placental side in one case. There were seven single and 10 multiple cysts. Cyst diameters ranged from 3.3 to 11.3 mm (mean, 5.6; standard deviation, ±2.1). Blood flow inside the cyst was noted in three cases (17.6%). HDlive clearly showed the spatial relationships among UCC, the umbilical cord, midgut herniation, yolk sac, and embryo. Location of UCC could be clearly identified with HDlive. HDlive Silhouette showed central cysts inside UCCs in seven cases (41.2%). HDlive Silhouette also clearly demonstrated the sac of midgut herniation in the umbilical cord in 12 cases (70.6%). All UCCs resolved before 15 weeks (mean, 11.1 weeks; standard deviation, ±1.5). All fetuses with UCCs showed good neonatal outcomes.

CONCLUSION

The incidence of UCC was high compared with that in previous reports. Color Doppler, HDlive, and HDlive Silhouette may provide information on the nature and origin of UCCs before 11 weeks of gestation. UCC before 11 weeks of gestation may be a common, transient, and benign finding.

Case report: Umbilical vessel aneurysm thrombosis and factor V Leiden mutation leading to fetal demise

Complicated pregnancies are nowadays a major public health concern, with possible lethality or sequelae both for the mother and the fetus. Blood coagulation disorders (including antiphospholipid syndrome, factor V Leiden mutation and antithrombin deficiency) and hypertensive gestational disorders are very well-known contributors of complicated pregnancies with poor fetal outcome, such as intrauterine growth retardation (IUGR) and fetal demise. Less commonly, vascular malformations of the placenta can also potentially lead to serious complications such as IUGR and fetal death. These malformations include hypercoiled umbilical cord, umbilical cord knot, umbilical cord varix, umbilical cord arterial or venous aneurysm, and velamentous insertion of the umbilical cord potentially leading to Benckiser's hemorrhage. Here, we report the case of a 29-year-old Gravida 2 Para 0 mother with previous history of stillbirth and smoking, admitted to the obstetrics department for the absence of fetal movement at 38 weeks of amenorrhea (WA). First-trimester and second-trimester routine ultrasounds were otherwise normal. Ultrasound performed at 38 WA revealed a 83 × 66 × 54 mm cystic heterogenous mass at the umbilical cord insertion. After delivery, fetal and placental pathology as well as maternal blood testing were performed. Fetal pathology was otherwise normal, except for diffuse congestion and meconial overload suggesting acute fetal distress. Fetal karyotype was normal (46 XX). Placental pathology revealed an umbilical artery aneurysm (UAA) at the base of the insertion of the umbilical cord, lined with a CD34⁺ CD31⁺ endothelium. After dissection, the aneurysm was filled with hemorrhagic debris, indicating aneurysm thrombosis. Histopathology revealed associated maternal vascular malperfusion (MVM) and increased peri-villous fibrin (IPF). Maternal blood tests revealed heterozygous factor V Leiden mutation, without other associated auto-immune conditions (such as antiphospholipid syndrome). Umbilical artery aneurysms remain extremely rare findings in the placenta, with <20 reported cases. Umbilical artery aneurysms have tendency to be located at the base of the insertion of the placenta, and lead to fetal demise in more than 60% of cases, mainly due to aneurysmal thrombosis, hematoma, possible vascular compression and/or rupture. Umbilical vessel aneurysms can be associated with trisomy 18 or 13. In our case, the association of factor V Leiden mutation, a hypercoagulable state, with UAA could explain massive thrombosis of the aneurysmal lumen and sudden fetal demise. Further consideration of current guidelines for surveillance and management of UAA would allow appropriate planned delivery in maternal care settings.

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.

Clinically Relevant Prenatal Ultrasound Diagnosis of Umbilical Cord Pathology

Umbilical cord abnormalities are not rare, and are often associated with structural or chromosomal abnormalities, fetal intrauterine growth restriction, and poor pregnancy outcomes; the latter can be a result of prematurity, placentation deficiency or, implicitly, an increased index of cesarean delivery due to the presence of fetal distress, higher admission to neonatal intensive care, and increased prenatal mortality rates. Even if the incidence of velamentous insertion, vasa praevia and umbilical knots is low, these pathologies increase the fetal morbidity and mortality prenatally and intrapartum. There is a vast heterogeneity among societies’ guidelines regarding the umbilical cord examination. We consider the mandatory introduction of placental cord insertion examination in the first and second trimester to practice guidelines for fetal ultrasound scans. Moreover, during the mid-trimester scan, we recommend a transvaginal ultrasound and color Doppler assessment of the internal cervical os for low-lying placentas, marginal or velamentous cord insertion, and the evaluation of umbilical cord entanglement between the insertion sites whenever it is incidentally found. Based on the pathological description and the neonatal outcome reported for each entity, we conclude our descriptive review by establishing a new, clinically relevant classification of these umbilical cord anomalies.

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.

Additional benefits of three-dimensional ultrasound for prenatal assessment of twins

Three-dimensional ultrasound (3DUS) may provide additional information for prenatal assessment of twins. It may improve the diagnostic confidence of dating, nuchal translucency (NT) and chorionicity assignment in twin pregnancies. The "virtual 3DUS placentoscopy" can guide selective fetoscopic laser photocoagulation (SFLP) to treat twin-twin transfusion syndrome (TTTS). Volumetric assessment of the dysmorphic acardiac twin with the Virtual Organ Computer-aided Analysis (VOCAL) software is more accurate than the conventional ultrasound measurement. Twin anemia polycythemia (TAP) sequence and selective intrauterine growth restriction (sIUGR) may be clinically monitored with 3DUS placental volume (PV) and power Doppler vascular indices. Congenital anomalies are more common in twins. Evaluation of fetal anomalies with 3DUS could assist perinatal management. The 3DUS power Doppler can provide a better understanding of true and false umbilical cord knots, which are commonly found in monoamniotic (MA) twins. Single demise in monochorionic (MC) twin pregnancies can cause severe neurologic morbidity in the surviving co-twin. Prenatal prediction of brain injury in the surviving co-twin with unremarkable neurosonographic examination is difficult. The 3DUS power Doppler may aid in prenatal detection of subtle abnormal cerebral perfusion. Prenatal assessment of conjoined twins with 3DUS is important if emergency postnatal surgical separation is anticipated. There is no significant additional advantage in using real-time 3DUS to guide prenatal interventions. Assessment of the cervix and pelvic floor during twin pregnancies is enhanced with 3DUS. Due to lack of high-quality studies, routine prenatal 3DUS in twin pregnancies needs to be balanced with risks of excessive ultrasound exposure.

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.

Third trimester intrauterine fetal death caused by arterial aneurysm of the umbilical cord

Umbilical artery aneurysm (UAA) of the umbilical cord is an extremely rare lesion, with only 8 reported cases in the English-language literature; 7 of these were associated with significant fetal morbidity or mortality and 4 were associated with fetal trisomy 18. We report an additional case of UAA with normal karyotype that resulted in intrauterine growth restriction and fetal demise. It has been suggested that these aneurysms cause fetal hypoxia and intrauterine fetal death, either by compression of the umbilical vein or by acute kinking of the umbilical cord. Cytogenetic analysis should be performed in all cases diagnosed with this unusual lesion, and placental mosaicism for trisomy 18 should be excluded.

Ultrasound and fetal diagnosis

PURPOSE OF REVIEW

The purpose of this review is to highlight publications from the last year that have advanced the use of ultrasound in obstetrics.

RECENT FINDINGS

Anatomic examination of the fetus in the first trimester has been emphasized because it allows for early diagnosis of many conditions. The prevalence of absent nasal bone, a marker for trisomy 21, in euploid fetuses depends on ethnicity. Nasal bone hypoplasia is another marker for Down syndrome. Studies on genetic screening in the first trimester have involved various serum analytes, adjustments in timing and calculations, use in multiple gestations, and the association of extreme measurements with adverse outcomes. A first-trimester integrated screening approach, which incorporates nuchal translucency, nasal bone, crown-rump length, pregnancy-associated plasma protein-A, and free beta-human chorionic gonadotropin, has the potential to maximize detection rates of Down syndrome and trisomy 18 and minimizes the screen-positive rate. The value of combining first and second-trimester results in sequential, contingent, or integrated screening protocols has been assessed. Isolated mild ventriculomegaly (10-12 mm) may prove to be a normal variant, and the role of 'soft' ultrasound markers in genetic counseling continues to be debated. Anomaly or high-risk status detection in the second trimester has been enhanced by the use of Doppler, 3D/4D ultrasound, and magnetic resonance imaging.

SUMMARY

Imaging techniques have been critical in the development of screening methods for Down syndrome or trisomy 18 and for euploid fetuses at high risk for adverse outcomes.