O. Shen

The fetal venous system, Part II: ultrasound evaluation of the fetus with congenital venous system malformation or developing circulatory compromise.

The human fetal venous system is well‐recognized as a target for investigation in cases of circulatory compromise, and a broad spectrum of malformations affecting this system has been described. In Part I of this review, we described the normal embryology, anatomy and physiology of this system, essential to the understanding of structural anomalies and the sequential changes encountered in intrauterine growth restriction and other developmental disorders. In Part II we review the etiology and sonographic appearance of malformations of the human fetal venous system, discuss the pathophysiology of the system and describe venous Doppler investigation in the fetus with circulatory compromise. Copyright

Added value of three-/four-dimensional ultrasound in offline analysis and diagnosis of congenital heart disease.

Many published studies have shown that application of three‐dimensional (3D) and real‐time 3D (4D) ultrasound modalities can improve certain aspects of fetal echocardiography, but have left open the question of whether these modalities improved the accuracy of prenatal detection of anatomical fetal cardiovascular malformations. We aimed to determine whether 3D/4D ultrasound improved diagnostic ability in cases of congenital heart disease (CHD).

The fetal venous system, Part I: normal embryology, anatomy, hemodynamics, ultrasound evaluation and Doppler investigation

Since its introduction in the mid‐1980s sonographic evaluation of the human fetal venous system has advanced dramatically. The venous system is well‐recognized as a target for investigation in cases of circulatory compromise, and a broad spectrum of malformations affecting this system has been described. Appreciation of the normal embryology, anatomy and physiology of this system is essential to an understanding of structural anomalies and the sequential changes encountered in intrauterine growth restriction or other developmental disorders. We review the normal embryology, anatomy, and hemodynamics of the human fetal venous system, and provide an overview of Doppler investigation, as well as three‐ and four‐dimensional ultrasound modalities and their application to this system. Copyright

Shunt diameter in agenesis of the ductus venosus with extrahepatic portosystemic shunt impacts on prognosis

Agenesis of the ductus venosus (ADV) is a rare condition in which there are two variants of umbilical vein drainage: intrahepatic shunt or extrahepatic (portosystemic) shunt. It has been posited that the extrahepatic variant carries a poorer prognosis. However, in the absence of associated anomalies there is still a wide variation in outcome. We evaluated the portal system in cases of ADV and aimed to identify parameters that might predict outcome.

Fetal heart ventricular mass obtained by STIC acquisition combined with inversion mode and VOCAL

Estimation of fetal heart ventricular mass is important for fetal cardiac evaluation in cases of structural or functional cardiac disorders or extracardiac factors. It may be used with other cardiac parameters to ascertain the severity and prognosis of such disorders, or the nature and timing of intervention. We applied a novel technique combining spatiotemporal image correlation (STIC) with three‐dimensional inversion mode and Virtual Organ Computer‐aided AnaLysis (VOCAL™) for fetal cardiac mass assessment in healthy fetuses in the second and third trimesters.

The added value of 3D/4D ultrasound imaging in fetal cardiology: has the promise been fulfilled?

As sonography matures, with its constant technological advances and ever-growing base of experienced examiners, it is reasonable to expect that its sensitivity and specificity in the diagnosis of fetal anomalies will increase. Perhaps the most dramatic advance has been the introduction of three-dimensional (3D) and real-time 3D (4D) ultrasound imaging1–7, which have become common adjuncts to fetal examinations in many centers. In fetal echocardiography, the 4D ultrasound modality applied most widely to the assessment of structure and function is spatiotemporal image correlation (STIC). Some 50 papers have been published on STIC since its first appearance in 2003 in this Journal8,9 and two more papers examining the reproducibility and reliability of STIC appear in this issue. The study by Bennasar et al.10 examines the reliability of qualitative evaluation and quantitative measurements of STIC-derived images. The study by Uittenbogaard et al.11 uses an in-vitro balloon model to examine the reproducibility of STIC-derived ventricular volume measures. While these studies add to the literature on STIC technology itself, they do not address another practical aspect of our use of STIC: does it improve rates of diagnosis or diagnostic accuracy in fetal echocardiography? Briefly, following STIC acquisition, rendered 3D ultrasound and multiplanar images of the heart are created from the volume dataset. The different views are available for review as still or moving images. During acquisition, STIC can be combined with Bflow, color or power Doppler, high-definition power Doppler and tissue Doppler. During post-processing, visualization modalities such as 3D volume rendering, inversion mode and tomographic ultrasound imaging (TUI) can be applied12–20. The saved volume can be manipulated offline, minimizing patient scanning time. STIC appears to offer promise of improvement in four main areas: increased diagnostic accuracy by virtue of the ability to view the heart from planes other than the acquisition plane and the depth perspective available on rendered images; evaluation of unique functional parameters; data availability for expert review offline, even from a remote computer; and improved patient counseling and interdisciplinary consultation through more comprehensible images, as well as creation of a library of cardiac anomalies that would be invaluable teaching materials for professional education. The images produced by this technology9,21 are impressive, and occasionally allow potentially complicated diagnoses to be made at a glance. But has 3D/4D ultrasound imaging in general, and STIC in particular, enhanced our diagnostic capabilities in fetal cardiology? Has it resulted in improved screening results and diagnostic accuracy? Has the promise been fulfilled? The STIC technique is readily acquired in most cases22, and integrating STIC does not increase scanning time materially. This has also been our experience. By transmitting STIC datasets on the internet, remote diagnoses of anomalies have been achieved as early as 11 weeks’ gestation16. We and others have applied STIC technology in teaching fetal cardiology, and find it to be an effective training tool for both normal fetal echocardiography and elucidating fetal cardiovascular anomalies. 3D ultrasound23 and STIC24–27 also facilitate the evaluation of cardiac function: only by using 3D/4D ultrasound can cardiac volumes be measured reliably and easily27,28 and derivate indices such as the ejection fraction23 and 4D myocardial performance index25 be calculated, opening up new areas of research and clinical application.

Omega-shaped variant of the umbilical artery: prenatal diagnosis and outcome.

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.

A comparison of methods for construction of fetal reference charts

Reference charts for fetal measures are used for early detection of pregnancies that should be monitored closely. Construction of reference charts corresponds to estimation of quantiles of a distribution as a function of gestational age. Existing methods have been developed under various modeling assumptions, typically by fitting a polynomial regression to certain functionals of the distributions (e.g., mean, standard deviation, and quantiles). We use a large dataset to compare various existing methods for construction of reference charts. We also relax the assumptions of a parametric polynomial link between the distribution parameters and age and consider cubic splines and discretization of age in order to compare charts based on more flexible and simpler models, respectively. We compare the different methods using various tools and demonstrate the importance of considering performance measures calculated from age-stratified data. We also examine the question of sample size. We compare our charts to similar charts that have been recently published and emphasize that the source of an apparent heterogeneity should be investigated. We conclude that the choice of which method to use for construction of reference charts should take the following into account: available sample size, validity of normality assumption, and results of various performance measures.

Delivering elsewhere between the first and second deliveries is a risk marker for obstetric complications in the second delivery

PurposeWe speculate that parturients who deliver elsewhere between the first and second deliveries compose a unique clinical group, characterized by higher rates of cesarean section (CS) both in the first and second deliveries, compared with parturients who deliver both deliveries at the same hospital.MethodsA retrospective study conducted at Shaare Zedek Medical Center in a tertiary university-affiliated hospital. The cohort included all women in the second delivery, agedxa0≤24xa0years with a singleton pregnancy who delivered their second child in our medical center during 2010–2012. Parturients who delivered both the first and second children in our medical center (“stayers”) were compared with parturients who delivered their first child in a different hospital (“switchers”). Groups were compared in regard to history of CS in the first delivery and obstetric complications in the second delivery, including CS, instrumental vaginal delivery (IVD), preterm delivery (PTD), and postpartum hemorrhage (PPH). Logistic regressions were constructed to study if delivering elsewhere between the first and second deliveries was a risk for adverse pregnancy outcome, followed by multivariate analysis controlling for confounders.ResultsIn all, 4166 parturients were included: “stayers”xa0=xa03163 and “switchers”xa0=xa01003. History of CS in the first delivery was approximately twice as prevalent in “switchers” (12 versus 6.3xa0%, pxa0<xa00.000). “Switchers” experienced higher rates of CS: ORxa0=xa01.8 (95xa0% CI 1.2–2.3); IVD: ORxa0=xa01.3 (95xa0% CI 0.8–2.1); and PTD (<37w): ORxa0=xa01.4 (95xa0% CI 1.0–1.9).ConclusionsParturients who deliver elsewhere between the first and second childbirth are at increased risk for CS and PTD in the second delivery; hence, the decision to deliver elsewhere after the first delivery should be considered as a risk marker for obstetric complication.

OC23.04: Superior imaging the fetal cerebellar vermis with 3D ultrasound multiplanar reconstruction and VCI‐C to obtain the mid‐sagittal plane

Methods: We studied 92 normal fetuses retrospectively on routine sonographic examination between 17 and 39 weeks’ gestation for visibility of the subplateintermediate zone interface and the echogenicity of the subplate relative to the intermediate zone. Results: The subplate-intermediate zone interface was identified in all fetuses between 18 and 28 weeks (n = 57) provided that there was adequate visualization of intracranial structures. The subplate appeared anechoic, and the intermediate zone homogeneously more echogenic than the subplate in all fetuses before 28 weeks in 100% of fetuses. Between 28 and 34 weeks, the interface between intermediate zone and subplate was well-defined in 6/22 fetuses, was faintly seen and/or less well-defined, in 10/22 fetuses, and was not visible in 7/22. The intermediate zone was not identified in any fetus after 34 weeks (n = 13). Conclusions: The fetal subplate and intermediate zones can be reliably demonstrated on routine sonography before 28 weeks, and disappear after 34 weeks. These findings reflect normal gestational age-dependent laminar patterns of cerebral development and are consistent with histological findings. Familiarity with normal sonographic appearances of cerebral lamination may assist in early diagnosis of cortical abnormalities.