OP22.03: First trimester diagnostic accuracy of two‐dimensional ultrasound technique in congenital heart diseases and great arteries anomalies

Abstract

To assess the accuracy of a standard first-trimester (FT) conventional two-dimensional ultrasound (2DUS) examination protocol in detecting congenital heart diseases (CHDs) and great arteries anomalies, in an unselected population. This is an eight-year single centre study, performed in a FT screening for aneuploidies program. We stored the cardiac sweep digital video clips, in duplex two-dimensional/two dimensional colour, from an oblique lateral insonation from the right shoulder. We used 2DUS re-examination by a team of specialists, pathological examination, and subsequent re-examination as the reference standard methods. In 20015 FT scanned fetuses, positive 2DUS diagnosed both major and minor CHDs with high accuracy (specificity 99.9%). Positive likelihood ratios were1896.83 for major and 920 for minor heart anomalies. Sensitivity was lower for minor defects than for major CHDs (40% vs 55.17%) with discrepancies between positive predictive values (40% vs 88.89%). The detection rates varied widely being: 88.25% (15/17) for complete atrioventricular septal defect, 87.5% (7/8) for hypoplastic left heart syndrome, 88.88% (8/9) for isolated great arteries transposition, 43.75% (7/16) for tetralogy of Fallot, 25% (2/8) for isolated aortic coarctation and 66.66% (2/3) for isolated aortic arch anomalies (normal heart) cases. In late FT the 2D ultrasound is an accurate tool in screening for some of the major CHDs. Using a standardised and low time-consuming technique will probably raise detection rates in this specific group of diseases. It will lower the operator-dependency and will eliminate the fetal position-dependency, two main reasons for the delayed diagnosis in certain CHDs cases. Despite the extremely low number of false positive cases, the overall accuracy of the method is too low for introducing it in national screening programs. This is mainly due to the spectrum bias of CHDs, with poor FT ultrasound markers in some cases and an evolving pattern in others. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.