Comprehensive imaging review of abnormalities of the umbilical cord

Prenatal diagnosis of the umbilical cord torsion at the placental cord insertion site: A case report and literature review

A 35-year-old woman (gravida 1, para 0) was admitted to our hospital at 28 weeks' gestation with vaginal bleeding from placenta previa. Severe fetal bradycardia was observed during fetal heart rate monitoring. Ultrasonography showed widely dilated veins on the fetal surface of the placenta and an extraordinarily low umbilical artery peak systolic velocity in the Doppler study. Umbilical cord torsion was suspected. On the subsequent day, we performed a cesarean section due to worsening fetal heart rate patterns. Umbilical artery blood gas analysis indicated severe acidemia (pH 7.063), and umbilical cord torsion was confirmed at the placental cord insertion site. Diagnosing UCT prenatally is challenging; however, it can be suspected by scanning for the widely dilated veins on the fetal placental surface, termed as the "Sunset Sign," an abnormally low umbilical artery peak systolic velocity, and other fetal Doppler abnormalities.

The association between increased fetal movements in the third trimester and perinatal outcomes; a systematic review and meta-analysis

BACKGROUND

Fetal movement monitoring is one of the strategies used to assess the fetus's health. Until now, most studies focused on the decreased fetal movement and neonatal outcome, although this systematic review and meta-analysis is designed to assess the association between increased fetal movements (IFM) with perinatal outcomes.

METHOD

The electronic databases including PubMed, Scopus, Web of Science, and EMBASE were systematically searched for studies investigating the perinatal outcome of women with increased fetal movements from inception to July 2023. Following that, a random-effect meta-analysis model was used to obtain the combined diagnostic and predictive parameters including perinatal mortality (still birth and early neonatal mortality), operative delivery, Apgar score, neonatal resuscitation at birth and NICU Admission.

RESULTS

After the initial screening, seven studies examining the association between increased third trimester fetal movement and various perinatal outcomes were included. Meta-analysis revealed a significant reduction in the risk of cesarean delivery among patients with IFM compared to controls, suggesting a potential protective effect during childbirth. However, no statistically significant difference was observed in birth weight, small or large for gestational age births, neonatal intensive care unit admission, maternal age, umbilical cord around the neck, gestational diabetes mellitus, and hypertension, indicating that IFM may not be a major predictor of adverse perinatal outcomes or maternal conditions. Notably, IFM was significantly associated with a higher likelihood of labor induction.

CONCLUSION

The findings suggest that IFM may have a protective effect against cesarean delivery. Additionally, IFM does not appear to be significantly associated with maternal age, umbilical cord around the neck, gestational diabetes mellitus and hypertension. However, the observed significant association with labor induction warrants further investigation.

Knots of the umbilical cord: Incidence, diagnosis, and management

Knot(s) of the umbilical cord have received emphasis because the clinical assessments and sonographic literature show a crucial role in fetal outcomes. The true umbilical cord knot could be a knot in a singleton pregnancy or an entanglement of two umbilical cords in monoamniotic twins. Clinical manifestations are almost silent, which can raise clinical challenges. They worsen outcomes, and the pathology can be easily missed during prenatal visits because ultrasonographers do not pay attention to the cord during an obstetric ultrasound scan. However, most medical centers now have ultrasound machines that improve fetal assessment. The umbilical cord should be routinely evaluated during a fetal assessment, and suspicion of an umbilical cord knot can be more frequently diagnosed and is detected only incidentally. Clinical outcome is usually good but depends on the knot's characteristics and if it is tight or loose. In this review, we discuss pathophysiology, the theories on formation, the main risk factors, ultrasound signs and findings, different opinions in the management, and features of pregnancy outcomes feature.

Umbilical Cord Diseases Affecting Obstetric and Perinatal Outcomes

BACKGROUND

(1) The aim of this article is to describe the physiopathology underlying umbilical cord diseases and their relationship with obstetric and perinatal outcomes. (2) Methods: Multicenter case series of umbilical cord diseases with illustrations from contributing institutions are presented. (3) Results: Clinical presentations of prenatal ultrasound findings, clinical prenatal features and postnatal outcomes are described. (4) Conclusions: Analysis of our series presents and discusses how umbilical cord diseases are associated with a wide variety of obstetric complications leading to a higher risk of poor perinatal outcomes in pregnancies. Knowing the physiopathology, prenatal clinical presentations and outcomes related to umbilical diseases allow for better prenatal counseling and management to potentially avoid severe obstetric and perinatal complications.

How to Reach the Best Ultrasound Performance in the Delivery Room

Ultrasonography is an instrument that is present in the maternal-fetal assessment throughout pregnancy and with widely documented benefits, but its use in intrapartum is becoming increasingly relevant. From the assessment of labor progression to the assessment of placental disorders, ultrasound can be used to correlate with physiological findings and physical examination, as its benefit in the delivery room cannot yet be proven. There are still few professionals with adequate training for its use in the delivery room and for the correct interpretation of data. Thus, this article aims to present a review of the entire applicability of ultrasound in the delivery room, considering the main stages of labor. There is still limited research in evidence-based medicine of its various possible uses in intrapartum, but it is expected that further studies can bring improvements in the quality of maternal and neonatal health during labor.

Placental and Umbilical Cord Anomalies Diagnosed by Two- and Three-Dimensional Ultrasound

The aim of this review is to present a wide spectrum of placental and umbilical cord pathologies affecting the pregnancy. Placental and umbilical cord anomalies are highly associated with high-risk pregnancies and may jeopardize fetal well-being in utero as well as causing a predisposition towards poor perinatal outcome with increased fetal and neonatal mortality and morbidity. The permanent, computerized perinatology databases of different international centers have been searched and investigated to fulfil the aim of this manuscript. An extended gallery of prenatal imaging with autopsy correlation in specific cases will help to provide readers with a useful iconographic tool and will assist with the understanding and definition of this critical obstetrical and perinatological issue.

A Retrospective Cohort Analysis of the Genetic Assay Results of Foetuses with Isolated and Nonisolated Umbilical Cord Cyst

Objective

To analyse the risk of clinical chromosomal abnormalities in foetuses with umbilical cord cysts.

Methods

Data from all genetic assays that were performed as part of invasive prenatal diagnoses of umbilical cord cysts between October 2014 and June 2021 were retrospectively collected from Guangdong Women and Children Hospital. We compared the differences in genetic assay findings in isolated and nonisolated umbilical cord cyst cohorts.

Results

A total of 49 singleton pregnancies and 2 foetuses that were one of the cotwins in monochorionic twin pregnancies were enrolled in the cohort; 20 isolated and 31 nonisolated umbilical cord cysts were identified in the cohort. One foetus (5%, 1/20) in the isolated umbilical cord cyst group showed chromosomal abnormalities and 17p12 microduplication. Twelve cases (38.7%, 12/31) of chromosomal abnormalities, including seven cases of trisomy 18, two cases of trisomy 13 and three cases of microdeletion, were identified in the nonisolated umbilical cord cyst group. The incidences of chromosomal abnormalities between the two groups were significantly different (1/20, 5% vs 13/31, 38.7%, p=0.003). There was no relative pathological medical exome sequencing finding in the three foetuses suffering from nonisolated umbilical cord cysts whose parents chose to undergo chromosomal microarray analysis (CMA) and medical exome sequencing.

Conclusion

This retrospective cohort study evaluated the value of CMA in foetuses with umbilical cord cysts and suggested that copy number variants (CNVs) may be the basic genetic aetiological factors that should be considered for diagnostic evaluation. We recommended CMA as a basic genetic evaluation in cases of umbilical cord cysts, especially in nonisolated cases.

Furcate umbilical cord insertion with a bilobed placenta identified on prenatal ultrasonography

A furcate cord insertion is a rare finding, which increases the risk of adverse fetal outcomes. There are few reports of prenatal detection in the literature. We present a case of prenatally detected furcate cord insertion, diagnosed at 39 weeks' gestation and delivered by elective caesarean section. The neonate was small for dates, but this finding was non-specific due to smoking during pregnancy. No other adverse effects to the fetus were found. The placenta required manual removal after attempted cord traction resulted in vessel avulsion at the furcate cord insertion site. Further research is required to develop recommendations for the safe management of this condition.

Imaging Review of Obstetric Sequelae of Maternal Diabetes Mellitus

Diabetes mellitus, whether preexisting or gestational, poses significant risk to both the mother and the developing fetus. A myriad of potential fetal complications in the setting of diabetic pregnancies include, among others, congenital anomalies, delayed fetal lung maturity, macrosomia, and increased perinatal morbidity and mortality. Congenital anomalies most commonly involve the nervous, cardiovascular, genitourinary, and musculoskeletal systems. Delayed fetal lung maturity, probably secondary to hyperglycemia suppressing surfactant secretion, is a major determinant of perinatal morbidity and mortality. Besides the potential complications encountered during cesarean delivery in macrosomic fetuses, vaginal delivery is also associated with increased risks of shoulder dystocia, clavicular and humeral fractures, and brachial plexus palsy. Maternal complications are related to the increased risk of hypertensive diseases of pregnancy and associated preeclampsia and hemolysis, elevated liver function, and low platelets (HELLP) syndrome, as well as complications encountered at the time of delivery secondary to fetal macrosomia and cesarean delivery. Additional conditions encountered in the setting of maternal diabetes include polyhydramnios, placental thickening, and two-vessel umbilical cord, each of which is associated with adverse fetal and maternal outcomes including fetal growth restriction, preterm labor, placental abruption, and premature rupture of membranes. Imaging plays a vital role in the evaluation of the mother and the fetus and can provide invaluable information that can be used by maternal fetal medicine to manage this patient population effectively. The authors review the pathophysiologic alterations induced by diabetes in pregnancy, discuss the imaging spectrum of diabetic embryopathy, and provide a detailed review of potential associated maternal complications. Online supplemental material is available for this article. ^©RSNA, 2021.

Fetoplacental vasculature as a model to study human cardiovascular endocrine disruption

Increasing evidence has associated the exposure of endocrine-disrupting chemicals (EDCs) with the cardiovascular (CV) system. This exposure is particularly problematic in a sensitive window of development, pregnancy. Pregnancy exposome can affect the overall health of the pregnancy by dramatic changes in vascular physiology and endocrine activity, increasing maternal susceptibility. Moreover, fetoplacental vascular function is generally altered, increasing the risk of developing pregnancy complications (including cardiovascular diseases, CVD) and predisposing the foetus to adverse health risks later in life. Thus, our review summarizes the existing literature on exposures to EDCs during pregnancy and adverse maternal health outcomes, focusing on the human placenta, vein, and umbilical artery associated with pregnancy complications. The purpose of this review is to highlight the role of fetoplacental vasculature as a model for the study of human cardiovascular endocrine disruption. Therefore, we emphasize that the placenta, together with the umbilical arteries and veins, allows a better characterization of the pregnant woman's exposome. Consequently, it contributes to the protection of the mother and foetus against CV disorders in life.

From stem cells to spiral arteries: A journey through early placental development

Early placental development lays the foundation of a healthy pregnancy, and numerous tightly regulated processes must occur for the placenta to meet the increasing nutrient and oxygen exchange requirements of the growing fetus later in gestation. Inadequacies in early placental development can result in disorders such as fetal growth restriction that do not present clinically until the second half of gestation. Indeed, growth restricted placentae exhibit impaired placental development and function, including reduced overall placental size, decreased branching of villi and the blood vessels within them, altered trophoblast function, and impaired uterine vascular remodelling, which together combine to reduce placental exchange capacity. This review explores the importance of early placental development across multiple anatomical aspects of placentation, from the stem cells and lineage hierarchies from which villous core cells and trophoblasts arise, through extravillous trophoblast invasion and spiral artery remodelling, and finally remodelling of the larger uterine vessels.

Implications of Endothelial Cell-Mediated Dysfunctions in Vasomotor Tone Regulation

Cardiovascular diseases (CVD) constitute the major cause of death worldwide and show a higher prevalence in the adult population. The human umbilical cord consistsof two arteries and one vein, both composed of three tunics. The tunica intima, lined with endothelial cells, regulates vascular tone through the production/release of vasoregulatory substances. These substances can be vasoactive factors released by endothelial cells (ECs) that cause vasodilation (NO, PGI2, EDHF, and Bradykinin) or vasoconstriction (ET1, TXA2, and Ang II) depending on the cell type (ECs or SMC) that reacts to the stimulus. Vascular studies using ECs are important for the analysis of cardiovascular diseases since endothelial dysfunction is an important CVD risk factor. In this paper, we will address the morphological characteristics of the human umbilical cord and its component vessels. the constitution of the vascular endothelium, and the evolution of human umbilical cord-derived endothelial cells when isolated. Moreover, the role played by the endothelium in the vasomotor tone regulation, and how it may be associated with the existence of CVD, were discussed.

Sonographic Diagnosis of Velamentous and Marginal Placental Cord Insertion

Routine second trimester ultrasound (US) examinations include an assessment of the umbilical cord given its vital role as a vascular conduit between the maternal placenta and fetus during fetal development. Placental cord insertion abnormalities can be identified during prenatal US screening and are increasingly recognized as independent risk factors for various complications during pregnancy and delivery. The purpose of this pictorial review is to illustrate examples of velamentous and marginal placental cord insertion with an emphasis on how to differentiate their morphology using color Doppler US.

A fetus with an immature umbilical cord teratoma associated with exomphalos: case report and review of the literature

Objective: To describe the antenatal and pathological features of an immature umbilical cord teratoma associated with exomphalos, and to review the literature on this subject. Case presentation: An abdominal wall defect, suspected to be an exomphalos, was identified during routine ultrasound examination performed at 13 weeks of gestation. The pregnancy was terminated. Fetopathological examination revealed an immature umbilical cord teratoma associated with exomphalos. Chromosomal microarray analysis was normal. Conclusions: Umbilical cord teratomas, albeit very rare, should be emphasized as a possible differential diagnosis when abdominal wall defects are detected. Since cord teratomas may lead to adverse fetal or neonatal outcomes, close follow-up of the fetus is recommended.

Midgut development in rat embryos using microcomputed tomography

The development of the mammalian gut was first described more than a century ago. Since then, it has been believed that a series of highly orchestrated developmental processes occur before the intestine achieves its final formation. The key steps include the formation of the umbilicus, the so-called "physiological herniation" of the midgut into the umbilical cord, an intestinal "rotation", and the "return of the gut" into the abdominal cavity. However, this sequence of events is predominantly based on histological sections of dissected embryos, a 2D technique with methodological limitations. For a better understanding of spatial relationships in the embryo, we utilized microcomputed tomography (µCT), a nondestructive 3D imaging method. Here, we show the detailed processes and mechanisms of intestinal development in rat embryos, including the development of the umbilicus, the formation of loops inside the umbilical coelom, and the subsequent shift of these loops into the abdominal cavity. Our 3D datasets of developing intestines will substantially advance the understanding of normal mammalian midgut embryology and offer new possibilities to reveal unknown mechanisms in the pathogenesis of congenital disorders.

Applicability of ultrasonography for detection of marginal sinus placenta previa

This study aimed to examine whether marginal sinus placenta previa, defined as when the marginal sinus just reaches the internal cervical os and placental parenchyma might be >2 cm from the internal cervical os, can be diagnosed using ultrasonography (US). We identified the placenta previa cases that underwent both US and magnetic resonance imaging (MRI) between April 2010 and December 2018 at our institution. The diagnostic discrepancies for marginal sinus placenta previa between US and MRI were examined retrospectively. Of the 183 cases of placenta previa, 28 (15.3%) cases were diagnosed as marginal sinus placenta previa using MRI. Among them, 18 cases (64.3%) could also be diagnosed using US. The sensitivity and specificity of the diagnosis of marginal sinus placenta previa using US were 64.3% and 92.9%, respectively. A change in US diagnosis occurred in 10 (35.7%) cases, all of which were diagnosed with low-lying placenta previa or marginal placenta previa and did not develop any serious miserable obstetrical outcomes. In conclusion, the diagnostic accuracy of US for detecting marginal sinus placenta previa was not significant. MRI examination may be required to accurately categorize the types of placenta previa.

How to read a fetal magnetic resonance image 101

Accurate antenatal diagnosis is essential for planning appropriate pregnancy management and improving perinatal outcomes. The provision of information vital for prognostication is a crucial component of prenatal imaging, and this can be enhanced by the use of fetal MRI. Image acquisition, interpretation and reporting of a fetal MR study can be daunting to the individual who has encountered few or none of these examinations. This article provides the radiology trainee with a general approach to interpreting a fetal MRI. The authors review the added value of prenatal MRI in the overall assessment of fetal wellbeing, discuss MRI protocols and techniques, and review the normal appearance of maternal and fetal anatomy. The paper concludes with a sample template for structured reporting, to serve as a checklist and guideline for reporting radiologists.

Structured evaluation and reporting in imaging of placenta and umbilical cord

The human placenta plays a pivotal role in development and growth of the fetus. Disorder of this multifunctional organ is central to various fetal disorders. Doppler sonography and MRI provide excellent diagnostic evaluation of the placental morphology and umbilical cord. Decades of experience in obstetric imaging have highlighted the need of careful prenatal assessment of placenta. However, in most of the routine obstetric scans, the evaluation and reporting of the placental examination is limited to the location and grade of the placenta. The purpose of this article is to review the existing literature and facilitate step-by-step evaluation of the placenta and umbilical cord by the radiologists.

Umbilical cord hypercoiling in two rhesus macaques (Macaca mulatta)

Obstruction of umbilical blood flow is a common cause of death in fetal nonhuman primates, but cord accidents have not been reported in the macaque. We describe two cases of cord accident in rhesus macaques (Macaca mulatta) resulting in fetal death at approximately 110 and 50 days of gestation, respectively.

Role of 2-Dimensional Ultrasound Imaging in Placental and Umbilical Cord Morphometry: Literature and Pictorial Review

Abnormalities of the placenta and umbilical cord have been associated with adverse pregnancy outcomes. Antenatal detection of placental and umbilical cord abnormalities using ultrasound (US) imaging is now gaining popularity with the advancements in obstetric US. This article reviews the use of 2-dimensional obstetric US as a tool to measure and assess placental and umbilical cord morphometry. It highlights the potential role of placental and umbilical cord morphometry as a valuable component of the screening tool for high risk pregnancies and identifies the need for further research to examine its feasibility.

MRI evaluation of the placenta from normal variants to abnormalities of implantation and malignancies

Even though the placenta has been known for millennia, it is still considered one of the most complex and least understood human organs. Imaging of the placenta is gaining attention due to its impact on fetal and maternal outcomes. MRI plays a vital role in evaluation of inconclusive cases by ultrasonography. It enables precise mapping of placental abnormalities for proper multidisciplinary planning and management. In this article we provide a comprehensive in-depth review of the role of antenatal MR in evaluating "The Placenta." We will describe the protocols and techniques used for MRI of the placenta, review anatomy of the placenta, describe MRI features of major placental abnormalities including those related to position, depth of implantation, hemorrhage, gestational trophoblastic neoplasia, and retained products of conception and discuss the added value of MRI in the management and preoperative planning of such abnormalities. Level of Evidence: 3 Technical Efficacy Stage: 5 J. Magn. Reson. Imaging 2019;50:1702-1717.

Modern Ultrasonography of the Umbilical Cord: Prenatal Diagnosis of Umbilical Cord Abnormalities and Assessement of Fetal Wellbeing

The umbilical cord is the only connection between the mother and the fetus, through which it is possible to transport respiratory gases, nutrients, and metabolites. Thanks to the umbilical cord, the fetus has also the ability to move, which is necessary for its proper psychomotor development. The correct structure and function of umbilical vessels and the entire umbilical cord determine the possibility of proper development and survival of the fetus. Umbilical cord anatomy should be assessed in the ultrasound examination in the first trimester. It is of vital importance to confirm the correct number of umbilical vessels and their intra-abdominal course, as well as carefully assessing the abdominal and placental insertion sites. In the latter half of pregnancy, the use of the Doppler imaging enables assessment of the function of the fetal-placental vessels, thus providing valuable information about the condition of the fetus.

Umbilical cord anomalies: antenatal ultrasound findings and postnatal correlation

Umbilical cord anomalies are rare. The differential diagnosis for a cystic structure around the umbilical cord and its insertion include pseudocyst, omphalomesenteric duct cyst, haemangioma, omphalocele or anterior abdominal wall defects. Although cord anomalies can be detected through antenatal ultrasound scans (US), very often a definitive diagnosis cannot be made. This may affect the management of the infant at birth. In cases where antenatal US was not diagnostic, current evidence supports the use of MRI to help in making an accurate diagnosis. We report two cases of umbilical cord anomalies. The first case was diagnosed in antenatal US as an omphalocele, but was found to be an allantoic cyst with hamartoma on postnatal diagnosis. The second case was not detected on antenatal US, and was diagnosed postnatally as a small omphalocele with vitellointestinal duct remnants.

Placental Imaging: Normal Appearance with Review of Pathologic Findings

The placenta plays a crucial role throughout pregnancy, and its importance may be overlooked during routine antenatal imaging evaluation. Detailed systematic assessment of the placenta at ultrasonography (US), the standard imaging examination during pregnancy, is important. Familiarity with the normal and abnormal imaging appearance of the placenta along with the multimodality and methodical approach for evaluation of its related abnormalities is necessary, so that radiologists can alert clinicians regarding appropriate prompt management decisions. This will potentially decrease fetal and maternal morbidity and mortality. This article reviews early placental formation and the expected imaging appearance of the placenta during pregnancy, as well as variations in its morphology. It also discusses various placental diseases and their potential clinical consequences. Placental pathologic conditions include abnormalities of placental size, cord insertion, placental and cord location, and placental adherence. Other conditions such as bleeding in and around the placenta, as well as trophoblastic and nontrophoblastic tumors of the placenta, are also discussed. US with Doppler imaging is the initial imaging modality of choice for placental evaluation. Magnetic resonance (MR) imaging is reserved for equivocal cases or when additional information is needed. Computed tomography (CT) has a limited role in evaluation of placental abnormalities because of the ionizing radiation exposure and the relatively limited assessment of the placenta; however, CT can provide important information in specific circumstances, particularly evaluation of trauma and staging of choriocarcinoma. This article also addresses recent techniques and updates in placental imaging, including elastography, diffusion-weighted MR imaging, and blood oxygen level-dependent (BOLD) MR imaging. These advanced imaging techniques may provide additional information in evaluation of abnormal placental adherence and new insights into placental pathophysiology in selected patients. Online supplemental material is available for this article. ^©RSNA, 2017.

Allantoic cyst of the umbilical cord detected in the first trimester with good pregnancy outcome

Allantoic cysts of the umbilical cord are embryological remnants of either the allantois or the omphalomesenteric duct. These cysts represent a rare ultrasound finding especially in the first trimester. Allantoic cysts can be associated with fetal malformations and chromosomal aberrations or are characterised by spontaneous resolution and good pregnancy outcome. Here we present a rare case of umbilical cord cyst detected by ultrasound in the first trimester with later resolution and favourable pregnancy outcome.

Congenital Cyst of the Umbilical Cord

Umbilical cord cysts warrant evaluation for structural defects and chromosomal anomalies such as trisomy 18, depending on the type of cyst. The appearance of an enlarged or "gigantic" cord has particular association with a patent urachus, often requiring operative exploration to repair the associated urachal remnant. We describe the unusual case of an umbilical cord cyst-measuring 9 cm in maximal diameter and comprising histopathological features of an urachalcyst-presenting in a healthy ex-36 week newborn with no associated anomalies.

Pseudotumors of the placenta

The placenta is one of the most common gross pathology specimens encountered by surgical pathologists, yet primary tumors are exceptionally rare and even rarer are entities with the potential to mimic malignancy. There are many nonneoplasticmass forming lesions in the placenta that are important to be aware of as many of these can be associated with adverse outcomes in the mother and fetus. Also important are entities which may be observed microscopically in the placenta and potentially confused as a malignancy. Knowledge of these potential pitfalls is essential to avoid making an incorrect diagnosis and causing undue alarm.

Sonographic Assessment of the Umbilical Cord

The umbilical cord (UC) is a vital connection between fetus and placenta. It constitutes a stable connection to the fetomaternal interface, while allowing the fetal mobility that is of great importance for fetal development in general and fetal neuromotor development in particular. This combination of mechanical stability and flexibility is due to the architecture of the UC. There is however a range of umbilical cord complications that may be life threatening to the fetus and these too can be explained to a large extent by the cord's structural characteristics. This review article discusses clinically relevant aspects of UC ultrasound.

Extrafetal Findings on Fetal Magnetic Resonance Imaging: A Pictorial Essay

Although US is the mainstay of fetal imaging, magnetic resonance imaging (MRI) has become an invaluable adjunct in recent years. MRI offers superb soft tissue contrast that allows for detailed evaluation of fetal organs, particularly the brain, which enhances understanding of disease severity. MRI can yield results that are similar to or even better than those of US, particularly in cases of marked oligohydramnios, maternal obesity, or adverse fetal positioning. Incidentally detected extrafetal MRI findings are not uncommon and may affect clinical care. Physicians interpreting fetal MRI studies should be aware of findings occurring outside the fetus, including those structures important for the pregnancy. A systematic approach is necessary in the reading of such studies. This helps to ensure that important findings are not missed, appropriate clinical management is implemented, and unnecessary follow-up examinations are avoided. In this pictorial essay, the most common extrafetal abnormalities are described and illustrated.

Umbilical cord accidents and legal implications

Umbilical cord accidents (UCA) are a significant cause of stillbirth. Although infrequent, litigation may occur when there is a poor outcome associated with UCA. With advances in imaging, the ability to identify UCA by ultrasound and magnetic resonance imaging raises awareness of the risk of a poor outcome. Management of a pregnancy with an identified UCA may require more fetal surveillance by both the mother and caregiver. This is especially important if there is a previous history of UCA with or without stillbirth. UCA should be an acknowledged risk which is part of prenatal screening. In the event of a poor outcome associated with UCA, it is recommended that the patient be fully informed of all prenatal information including images. Excellent communication with parents who are looking for answers after a tragic outcome may help to decrease litigation risk.