A. Comanescu

Improved detection rate of structural abnormalities in the first trimester using an extended examination protocol

To assess the potential of first‐trimester sonography in the detection of fetal abnormalities using an extended protocol that is achievable with reasonable resources of time, personnel and ultrasound equipment.

Right aortic arch with patent right ductus arteriosus and normal heart

The term ‘right aortic arch’ (RAA) refers to a congenital abnormal position of the aortic arch, that is, to the right of the trachea, with or without an abnormal branching pattern, and is one of the least frequently prenatally diagnosed cardiac abnormalities1–3. The main clue for the detection of RAA in large population studies and small case series has been absence of the normal ‘V’shaped confluence of the ductal and aortic arches (both to the left of the trachea) in the axial three vessels and trachea (3VT) view1–7, as a RAA and left ductus form an abnormal ‘U’-shape. Reviewing papers that have evaluated the associated conditions and outcomes of the different types of RAA, its occurrence with a right ductus arteriosus (RDA) has been reported with severe cardiac anomalies (tetralogy of Fallot, pulmonary atresia with ventricular septal defect, common arterial trunk)3,7,8 and high rates of 22q11 deletions7,9,10. We describe here a case of RAA with a RDA in which the heart was normal. This was easily recognizable in the 3VT view from the first trimester onwards, independent of the angle of insonation. Sonographic evaluations and image acquisitions were performed transabdominally using a Voluson 730 ultrasound machine (GE Medical Systems, Zipf, Austria). A 31-yearold low-risk pregnant woman, gravida 1 para 0, attended for first-trimester screening at our center. A cardiac transverse sweep showed an anatomically and functionally normal fetal heart, but a right-sided aortic arch and a V-shaped confluence with a patent RDA were observed on the 3VT view (Figure 1). Offline analysis by examiners experienced in fetal echocardiography resulted in similar conclusions. Invasive tests ruled out karyotype and 22q11 abnormalities. During the second and third trimesters normal views of the fetal heart were found on the standard axial approach (situs, area, axis, cardiac chambers, emergence of great vessels) (Figures 2a–c and Videoclip S1) and, in accordance with previous findings, an RAA and patent RDA were identified as a V-shaped

OP21.04: First trimester diagnosis of SUA—feasibility of the marker, importance in screening for aneuploidies

mosaicisms/translocations/deletions/sexual CA; only 2/13 women opted for TOP whereas 11/13 fetuses with normal morphology were delivered at term after a reassuring genetic counseling. 47/1423 (3,3%) fetuses had AS but normal karyotype: in 8 cases, anomalies were confirmed (3 major CHD, 1 NTD, 1 CDH, 2 nefropathies, 1 anomalous CNS). 39/1423 (2,7%) fetuses were false positive cases. Conclusions: CHD and ECA US screening performed by trained obstetricians at the time of NT measurements could identify a high rate of all aneuploidies at a low rate of false positives.

P25.03: Relation between nuchal translucency thickness and prevalence of chromosomal defects, miscarriage, fetal death and major fetal abnormalities

Objective: To determine whether Doppler velocimetry of the ductus venosus can improve the predictive capacity of increased nuchal translucency in the detection of trisomy 21 at 11–14 weeks of gestation. Methods: Ductus venosus Doppler ultrasound blood velocity waveforms were obtained prospectively at 11–14 weeks of gestation in 2280 consecutive singleton pregnancies. Waveforms were classified either as normal in the presence of a positive A-wave, or as abnormal if the A-wave was absent or negative. All cases were screened for chromosomal defects by a combination of maternal age and fetal nuchal translucency thickness. Concerm TN, a Down sindromy was suspected when the nuchal translucency was above the 95th centile. In 344 cases karyotyping was performed. Results: Down syndrome was found in 37 cases. On basis in the NT the overall detection rate, specificity, positive predictive value, negative predictive value and likelihood ratio for trisomy 21 were 85.7%, 97.1%, 99.9%, 28% and 44.9% respectively. On basis in the ductus venosus blood flow during atrial contraction the sensitivity, specificity, the negative and positive predictive values and likelihood ratio were 82.9%, 98.8%, 99.7%, 56.9%, 69% respectively. Conclusions: Enlarged nuchal translucency and abnormal ductus venosus blood flow are useful markers of trisomy 21 in the first trimester ultrasound screening, assessment of ductus venosus blood flow velocimetry could improve the predictive for the detection of Down syndrome.

OP14.06: Finding the hippocampus: challenge accepted

G. Kasprian2, G.M. Gruber1, G. Dovjak2, D. Bettelheim3, C. Haberler4, D. Prayer2 1Department for Anatomy, Centre of Anatomy and Cell Biology, Vienna, Austria; 2Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria; 3Department of Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria; 4Institute of Neurology/Neuropathology, Medical University of Vienna, Vienna, Austria

OC05.01: Reliability of first trimester structural sonographic extended evaluation

J. Degenhardt1, R. Schürg2, A. Kawecki3, M. Pawlik1, C. Enzensberger1, R. Stressig4, R. Axt-Fliedner1, T. Kohl3 1Division of Prenatal Medicine, University of Giessen and Marburg, Giessen, Germany; 2Department of Anesthesiology, University of Giessen and Marburg, Giessen, Germany; 3German Center for Fetal Surgery & Minimally Invasive Therapy, University of Giessen and Marburg, Giessen, Germany; 4University Hospital of Bonn, Bonn, Germany

OP11.01: Assessment of fetal 3D volumes at 11–13 + 6 weeks

Objectives: Part of the SONOSEROSCREEN project, at the end of the first trimester – 11–13+6 weeks, we are assessing the risk of chromosomal abnormalities and also make a primary assessment of fetal morphology. We investigated to what extent the aquision of a 3D ultrasound volume at the double test (combined test) can provide enlightening information on fetal morphology. Methods: During May 2010–December 2010 there were saved 72 3D volumes that were processed off-line for assessing the morphological parameters of the standard 11–13+6 weeks SONOSEROSCREEN ultrasound protocol. Ten parameters have been chosen as a benchmark for evaluation: the correct view of NT, the intracranial translucency and orbits, the choroid plexus, position of the fetal heart, the diaphragm, the image of the stomach, bladder, umbilical cord insertion and assessment of the four limbs. There were accepted for study only the volumes obtained in ideal conditions–a standard position for nuchal translucency measurement, the transducer facing the fetus and the interposition of amniotic fluid to ensure good quality images. Results: Images obtained by off-line manipulation of 3D volumes allowed us to obtain reference images in over 90% of cases–comparable to the 2D examination. Conclusions: Off-line examination allows a careful analysis of the morphology from 11 to 13+6 weeks, without the pressure of a conclusion ‘‘on the spot’’. It does not exceed the time devoted to the evaluation of 2D and the conclusion may be offered to the patient with the combined test result.

OC13.01: First trimester study of fetal heart with 3D/4D echocardiography: is the step forward here yet?

CD and CD for NRFS alone or in combination with MCA Doppler was assessed by decision tree analysis. Results: Retrograde net blood flow in aortic isthmus was observed in 8.3% (14/169) of the cases and only within the group of fetuses with MCA vasodilation (PI < 5th centile). Among the overall study population, cases with reversed aortic isthmus blood flow were associated with a significantly higher risk of CD (85.7% vs. 36.8%, P < 0.001) and CD for NRFS (85.7% vs. 24.5%, P < 0.001) than those with antegrade blood flow. Decision tree analysis indicated that incorporation of aortic isthmus showed an additional predictive value to brain Doppler abnormalities. Among the group with MCA vasodilation, reversed aortic isthmus blood flow allowed discrimination of cases with high or moderate risk of CD (85.7% vs. 54.5%, P < 0.01) and CD for NRFS (85.7% vs. 40.9%, P < 0.05). Conclusions: Identification of aortic isthmus reversed blood flow identifies a subgroup of term SGA fetuses with middle cerebral artery vasodilation with the highest risk of emergency cesarean delivery for non-reassuring fetal status.

OP29.09: Managing restricted babies—tough job

and the Spearman correlation coefficient calculated. The random selection of data points from each curve was repeated 1000 times. Median correlation coefficients and P-values are reported. Results: There was a highly significant negative correlation between UAPI and AC, normalised for gestation using Z-scores (median correlation coefficient = −0.2892/median P-value = 2.272e-5). Conclusions: In gastroschisis, there is a clear relationship between the degree of smallness of the baby’s abdominal circumference for gestation and the umbilical PI. This is not the case for normally grown babies, and implies that fetuses with gastroschisis may have small AC not simply because of the external displacement of the abdominal viscera but instead possibly mediated by hypoxia.

OC12.04: Efficiency and repeatability of recently described markers of early neurosonogram

Objectives: Screening at 11–14 weeks is changing from a simple NT measurement to a comprehensive first trimester anomaly scan. However, the detection of open neural tube defect (NTD) before 14 weeks is still a challenge, since lemon and banana signs, used in second trimester ultrasound, are rarely present. Aim of the study is to seek for simple first trimester signs to alert the examiner for the presence of NTD. Methods: The midsagittal view of the face used for NT and nasal bone measurements was analyzed in normal fetuses and fetuses with NTD. The region between the brain stem and occipital bone, includes the 4th ventricle (intracranial translucency = IT), the choroid plexus of the 4th ventricle and the future cisterna magna. Results: In normal fetuses between 11–14 weeks there is an increase in the anterior posterior diameters of posterior fossa structures. Fetuses with NTD detected prospectively and retrospectively showed however abnormal values due to the downward shifting of the brain stem. Conclusions: In the plane used for NT measurement the evaluation of the posterior part of the brain between the brain stem and the occipital bone appears to be the clue in suspecting NTD at the 11–14 weeks scan. Further prospective studies are needed to find the sensitivity of these observations during routine screening.