S. Horton

A study of the cost, accuracy, and benefits of 3-dimensional sonography compared with hysterosalpingography in women with uterine abnormalities

We conducted a prospective blinded study to evaluate the costs, accuracy, risks, and benefits of 3‐dimensional (3D) transvaginal sonography compared to hysterosalpingography.

Defining the fetal cardiac axis between 11 + 0 and 14 + 6 weeks of gestation: experience with 100 consecutive pregnancies

The purpose of this study was to establish normal fetal cardiac axis values during the first and early second trimesters of pregnancy.

Fetal left brachiocephalic vein in normal and abnormal conditions

To establish values of fetal left brachiocephalic vein (LBCV) dimensions during normal pregnancy and determine whether routine assessment of the LBCV may help in identifying fetuses with congenital abnormalities of this vessel.

OC01.02: A step towards standardization in sonographic assessment of fetal venous system: sequential analysis of five‐transverse views

L. Rode1,2, K. Klein3, K. Nicolaides4, E. Krampl-Bettelheim3, I. Vogel5, H. Larsen6, A. Holmskov7, K. Riis Andreasen8, N. Uldbjerg9, J. Ramb10, B. Bødker11, L. Skibsted12,2, L. Sperling13, S. Hinterberger14, L. Krebs15, H. Zingenberg16, E. Weiss17, I. Strobl18, L. Laursen19, J. Tranberg Christensen20, B. M. Hansen21, A. Lando21, A. Tabor1,2 1Department of Fetal Medicine 4002, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; 2Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark; 3Department of Obstetrics & Gynecology, Medical University of Vienna, Vienna, Austria; 4Harris Birthright Research Centre for Fetal Medicine, King’s College Hospital, London, United Kingdom; 5Department of Clinical Genetics, Aarhus University Hospital Skejby, Aarhus, Denmark; 6Department of Obstetrics & Gynecology, Aalborg Hospital, Aalborg, Denmark; 7Department of Obstetrics & Gynecology, Viborg Hospital, Viborg, Denmark; 8Department of Obstetrics & Gynecology, Hvidovre Hospital, Hvidovre, Denmark; 9Department of Obstetrics & Gynecology, Aarhus University Hospital Skejby, Aarhus, Denmark; 10Department of Obstetrics & Gynecology, Sønderborg Hospital, Sønderborg, Denmark; 11Department of Obstetrics & Gynecology, Hillerød Hospital, Hillerød, Denmark; 12Department of Obstetrics & Gynecology, Roskilde University Hospital, Roskilde, Denmark; 13Department of Obstetrics & Gynecology, Herlev Hospital, Herlev, Denmark; 14Department of Obstetrics & Gynecology, General Hospital of Klagenfurt, Klagenfurt, Austria; 15Department of Obstetrics & Gynecology, Holbæk Hospital, Holbæk, Denmark; 16Department of Obstetrics & Gynecology, Glostrup Hospital, Glostrup, Denmark; 17Department of Obstetrics & Gynecology, Medical University of Graz, Graz, Austria; 18Department of Obstetrics & Gynecology, Medical University of Innsbruck, Innsbruck, Austria; 19Department of Obstetrics & Gynecology, Odense University Hospital, Odense, Denmark; 20Department of Obstetrics & Gynecology, Gentofte Hospital, Gentofte, Denmark; 21Department of Neonatology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark

OP07.04: Fetal azygous vein: visualization, biometry and blood flow pattern between 11 and 40 weeks of gestation

Objectives: To define the feasibility of assessing the right subcalavian artery (RSA) in 1st and 2nd trimester ultrasonographic assessment of routine population and the association of ARSA with chromosomal, cardiac and extracardiac anomalies. Methods: RSA was prospectively evaluated since July 2009 in all routine patients booked in our fetal medicine Unit. We included 11–14 weeks assessment, pre-invasive US evaluation in patients that declined 1st trimester screening at booking and opted directly for fetal karyotyping due to maternal age ≥ 35 y and routine anomaly scan. All patients referred for increased NT, amniocentesis, cardiac or extracardiac abnormalities were excluded. Results: We have assessed 4068 routine patients, 3036 in the 1st and 3152 in the 2nd trimester; 2281 patients were assessed in both 1st and 2nd trimesters. RSA assessment was feasible in 2529 1st trimester exams (83%). Feasibility in the first trimester was related to the CRL/BMI ratio. In the 2nd trimester the feasibility was higher reaching 98%. The overall feasibility in our series was 91.1% (3709 feasible cases, considering both 1st and 2nd trimester evaluation). An ARSA was found in 49 fetuses (overall incidence 1.32% of the feasible cases) where 28 were detected in the 1st and 19 in the 2nd trimester. Nine of the 2nd trimester ARSA have been misdiagnosed in the 1st trimester assessment. Fetal echocardiography always confirmed the initial diagnosis, when an ARSA was detected in the screening scan (no false positive cases). Of the 49 ARSA, 39 were euploid with no other findings; the remaining 10 cases included 5 aneuploidies, 1 genetic syndrome, 1 22q11 microdeletion, 1 cardiac and 2 extracardiac abnormalities. Conclusions: The feasibility of RSA assessment in a routine population depends on gestational age and maternal BMI, with more than 80% feasible cases in the first trimester. A high rate of ARSA are associated with genetic or structural, abnormalities.

Orientation of the uterine fundus in reference to the longitudinal axis of the body: a 3-dimensional sonographic study.

The aim of this pilot study was to measure the angle of rotation of the uterus at the fundus from horizontal using 3‐dimensional sonography in women presenting for annual gynecologic examinations.

OP03.01: Evaluation of the uterine fundus orientation in relation to the longitudinal axis of the body by 3‐D ultrasound

W. Hofmann1, M. Stumm2, K. Haug3, C. Blank3, M. Wüstemann4, B. Schulze5, G. Raabe-Meyer5, M. Hempel6, M. Schelling7, E. Ostermayer8, S. Langer-Freitag6, T. Burkhardt9, R. Zimmermann9, M. Beck10, T. Schleicher10, Y. Kumar10, D. Schöner1, S. Grömminger1, M. Entezami2 1LifeCodexx AG, Konstanz, Germany; 2Zentrum für Pränataldiagnostik und Humangenetik, Berlin, Germany; 3Praenatal-Medizin und Genetik, Düsseldorf, Germany; 4Zentrum für Pränatalmedizin, Hannover, Germany; 5Praxis für Humangenetik, Hannover, Germany; 6Institut of Human Genetics, Technische Universität München, München, Germany; 7Praxis für Pränatale Diagnostik, München, Germany; 8Department of Obstetrics and Gynecology, Technische Universität München, München, Germany; 9Klinik für Geburtshilfe, Universitätsspital Zürich, Zürich, Switzerland; 10GATC Biotech AG, Konstanz, Germany

OC02.07: Fetal left brachiocephalic vein in normal and abnormal conditions

Objectives: To describe an extended algorithm CASSEAL for exploring the fetal cardiovascular system at the level of the fetal abdomen and thorax by ultrasound (US) axial views and the features concerning its clinical application. Methods: CASSEAL was applied in a cross-sectional study on 429 singleton and multiple gestations from the second trimester attending our unit for routine US examination or because of a suspected fetal abnormality. Using the common 5 axial views to evaluate de fetal heart (Yagel) as a starting point, we extend the exploration area caudally, adding 3 axial views to assess the hepatic venous circulation and cranially, 2 axial views for the upper mediastinum. This way CASSEAL is based on the acquisition of these 9 different axial views in B mode, from the umbilical vein to the subclavian arteries (Figure 1). The frequencies of visualization for each view and for all 9 views were determined, as was the time for the complete assessment of the 9 views. Interobserver agreement was previously estimated in a sample of 31 gestations (Kappa index, 0.89). Results: Figure 1 shows the 9 axial views that constitute the CASSEAL and illustrates the cardiovascular structures visualized in each view. Views I–III are used to assess the afferent and efferent vessels of the fetal liver and VIII–IX to study the upper mediastinum structures. The frequencies of visualization for each view and the complete set of the 9 views are shown in Table 1. Median exploration time was 5 minutes (IQR, 3–10 minutes). Conclusions: CASSEAL views were feasible and the 9 sonographic axial views were obtained relatively quickly in most cases (>73%). VIII view (Thy-box) presented the lowest frequency of visualization (74.6%). Clinical application of CASSEAL is useful for systematizing the US exploration of fetal cardiovascular structures and, thus, could contribute to the prenatal diagnosis of arterial, venous, and cardiac abnormalities given its wider exploration area.

OP12.04: Use of high‐definition color Doppler in the assessment of normal and abnormal fetal hearts in early gestation

Objectives: In Flanders (the Dutch speaking Northern part of Belgium) the prenatal detection rate of congenital heart diseases (CHD) is very low. The primary goal of this retrospective study is to determine the sensitivity, positive and negative predictive value (PPV and NPV) of nuchal translucency (NT) measurement for prenatal CHD diagnosis in a general low risk population and to consider if NT measurement is an effective screening tool for CHD. Methods: We used the registry of the General Medical Laboratory, handling the largest percentage of maternal serum samples for first trimester aneuploidy screening in Flanders, to select those fetuses with an enlarged NT. The outcome of these pregnancies was collected from the referring gynecologists and ultrasonographers. Results: In 102,472 maternal serum samples over a 9 years period, 303 (0.30%) pregnancies, had -at least onefetus with a NT of ≥ 3.5 mm. 156 fetuses were suitable for analysis. In this group the overall incidence of CHD was 7.7% in fetuses with a normal karyotype. The sensitivity for CHD in the group with a NT of ≥ 3.5 mm and normal fetal karyotype is 1.9% with a specificity of 99.9%, positive predictive value of 7.1% and negative predictive value of 99.4%. The false positive rate is 0.14%. The false negative rate is 98.1%. The likelihood ratio is 13.6. Conclusions: Low sensitivity and high false negative rate make first trimester NT measurement not an effective screening tool for CHD detection at population level.

OP14.05: Three‐dimensional sonography of the fetal posterior brain between 11 + 0–13 + 6 weeks gestation

(Lachmann et al., 2011). However, in our observation, the brain stem of spina bifida fetuses is characterized by kinking and thinning, rather than thickening. We examined the biometry and utility of these first trimester spina bifida markers in our population. Methods: Mid-sagittal facial images obtained at nuchal translucency screening between 11–0/7 and 13–6/7 weeks gestation were digitally stored. Normal (n = 500) and randomly interspersed spina bifida cases (n = 10) were analyzed by three blinded examiners. The BS was measured from the posterior border of the sphenoid bone to the anterior border of the fourth ventricle, and the BSOB from the latter to the anterior border of occipital bone, and adjusted for crown-rump length (CRL). Normality of distribution was confirmed with the Kolmogorov-Smirnov test, and means of spina bifida group and normals were compared by t-test. Results: BS diameter increased with CRL (R2 = 0.14; P < 0.0001), whereas BSOB and BS/BSOB ratio decreased with CRL (R2 = 0.168; P < 0.0001). BS diameter was significantly smaller in spina bifida fetuses (P < 0.0001; 4/10 cases below 5th%ile, none above 95%ile), and BS/BSOB ratio was significantly higher in the spina bifida group (P < 0.002; 6/10 cases above 95th%ile). With a 95% specificity, the above cutoff limits would yield a 40% and 60% sensitivity for SB detection, respectively. Conclusions: In our study population, spina bifida is associated with smaller brain stem diameters in comparison to normal first trimester fetuses. This would yield lower detection rates in screening with the BS/BSOB ratio than previously reported.