Fetal echocardiography at 11-13 weeks by transabdominal high-frequency ultrasound

OBJECTIVES: To assess the accuracy of fetal echocardiography at 11-13 weeks performed by well-trained obstetricians using a high-frequency linear ultrasound transducer. METHODS: Fetal echocardiography was performed by obstetricians immediately before chorionic villus sampling for fetal karyotyping at 11-13 weeks. Digital videoclips of the examination stored by the obstetrician were reviewed offline by a specialist fetal cardiologist. RESULTS: The obstetrician suspected 95 (95%) of the 100 cardiac defects identified by the fetal cardiologist and made the correct diagnosis in 84 (84%) of these cases. In 54 fetuses, the defect was classified as major and in 46 it was minor. In 767 (86.6%) cases, the heart was normal and in 19 (2.1%) the views were inadequate for assessment of normality or abnormality. A subsequent second-trimester scan in the normal group identified major cardiac defects in four cases. Therefore, the first-trimester scan by the obstetricians and cardiologists identified 54 (93.1%) of the 58 major cardiac defects. CONCLUSIONS: A well-trained obstetrician using high-resolution ultrasound equipment can assess the fetal heart at 11-13 weeks with a high degree of accuracy.