P27.09: Diagnostic accuracy of basic fetal heart examination at 11–13 weeks' gestation of pregnancy

Abstract

Investigate the diagnostic performance of a simplified fetal heart examination in a routine setting of first trimester ultrasound screening for aneuploidies. This was a prospective observational study, in which a basic cardiac examination applying the cross-sections of the 4-chamber and/or 3-vessels views using colour Doppler was performed at the 11 to 13 weeks' gestation scan in a routine setting in single pregnancies. A total of 1850 single fetuses performed first and second trimester ultrasound scans between January 1st 2016 and January 13th 2017. Overall, 1799 cases with second trimester scan, echocardiography or autopsy findings were included. In 1177 cases (65.4%) basic heart examination was not performed during first trimester because of difficult fetal position, maternal obesity with inadequate visualisation of the heart structures or when the examiner was not comfortable with early heart examination. Patients with incomplete anatomy scan at second trimester and with unknown outcome were excluded. In 622 cases (34.5%) a basic cardiac examination applying the cross-sections of the 4-chamber and / or 3-vessels views using colour Doppler was carried out. In total, there were 16 cases with a confirmed congenital heart defect (0.89%) and 16 cases of fetuses with chromosomal abnormalities. Evaluation by the 4-chamber and/ or 3 vessels view had a sensitivity and specificity of 66.7% and 99.5% respectively, with a positive and negative predictive values of 85.7% and 99.5%, respectively. Overall, at our unit, 37.5% of the cardiac malformations were detected at first trimester scan. Major heart anomalies such as hypoplastic left heart syndrome, pulmonary hypoplasia, transposition of the great vessels and atrioventricular septal defect were depicted at the 11-13 weeks' scan by performing basic heart evaluation. Basic heart views allow for selection of 67% cases with major cardiac malformations at the 11 to 13 weeks' routine ultrasound scan, providing the option for early confirmation by echocardiography.