P06.02: Introduction of ultrasound for nuchal translucency (NT) as part of combined screening test (CST): impact on local practice

Abstract

The type IIb is the most difficult type to diagnose among isolated total anomalous pulmonary venous drainages (isolated TAPVD) in the fetal period. We retrospectively reviewed a missed diagnoses case of isolated TAPVD (IIb) using spatio-temporal image correlation (STIC). At the time of screening test the fetus had some abnormal echocardiographic findings, the apex of the heart pointing more to the left than normal with the angle of the septum almost 70 degrees to the midline, upper septum of mitral valve being whitish and dimness, and aorta being located slightly anterior right side in 3 vessels view. B-mode and color Doppler mode STIC volumes were acquired and stored during echocardiographic examination at 28 weeks of gestational age using Voluson E8. Postnatal echocardiography was performed at 5 days of age because pulse oximeteric reading was 85%, and TAPVD IIb with common pulmonary venous chamber (CPV) was diagnosed. All pulmonary venous flow were going into the right atrium via CPV. At 15 days of age, the cardiac surgery was performed successfully. The reason why we could not make a correct diagnosis were that we took CPV as the left atrium (LA). In fact the real position of the LA was extremely deviated to the left side and the LA itself was small. We analyzed STIC gray-mode image rendered with surface texture and gradient light modes. Reconstructed STIC render images clearly showed the position of CPV and LA than gray-mode. The small LA could be easily confirmed. On the basis of our findings, we conclude that 4D images with gradient light mode may be a useful tool, as an adjunct to 2D echocardiography for prenatal diagnoses of TAPVD IIb. P06: ANEUPLOIDY AND FETAL ANOMALIES: FIRST TRIMESTER P06.01 Impact of universal prenatal screening program for Down syndrome in a local obstetric unit in Hong KongK. Leung, B. Lau, C. Poon, K. Kou, T. Ma O&G, Queen Elizabeth Hospital, Hong KongObjectives: To evaluate the impact of a universal screening strategy in the first trimester (including nuchal translucency, PAPP-A and β-HCG), introduced in a local public hospital during second half of 2010. Before July 2010, a prenatal screening or invasive test for Down syndrome was offered to women of 35 or above only. Methods: This was a cohort study in an obstetric department with total annual deliveries of around 6,000. All the sonographers were trained, and the markers were assayed in a certified laboratory. An invasive test was offered to women with a screen positive result (1 in 250 or above). Results: From 1 July to 31 December, 2010, of 2034 eligible women, 82.5%, 14.1%, 1.0%, and 2.4% opted for first trimester combined screening, second trimester biochemical screening, screening by nuchal translucency measurement alone, and nothing respectively. The overall false positive rate was 6.0%. Of 126 women being screened positive, 68 (54.0%), 29 (23.0%), 29 (23.0%) underwent chorionic villus sampling, amniocentesis, and no invasive test respectively. Compared to 2009, there was a slight decrease in the total number of invasive...