Sensitivity and specificity of second trimester anatomy ultrasound in the detection of abnormal fetal echocardiogram when performed by perinatologists

To determine the sensitivity and specificity of a detailed second trimester anatomy ultrasound in the prediction of abnormal fetal echocardiogram (FE) when both were performed by Maternal-Fetal Medicine (MFM) specialists. Retrospective cohort study of all patients with a singleton gestation who underwent a detailed second trimester anatomy ultrasound and FE performed by a group of US MFMs working at a tertiary-level urban academic centre with AIUM accreditation from July 2020 to September 2022. FE were performed as indicated by AIUM/ISUOG guidelines. FE with persistently suboptimal views were excluded. We calculated the sensitivity and specificity of a detailed anatomy ultrasound to detect abnormal views on FE. Among 2,695 pregnancies with a detailed second trimester anatomy ultrasound and FE performed by MFM, 34 (1.3%) pregnancies with persistently suboptimal cardiac views were excluded. Of the remaining pregnancies, 2,515 (94.5%) did not have any cardiac abnormalities noted on either scan. 49 scans were read as normal on anatomy ultrasound with subsequent abnormal views on FE, with a 36.8% false-negative rate. Meanwhile, 13 of the anatomy ultrasounds with cardiac abnormalities were normal on subsequent FE, with a false-positive rate of 0.5%. Thus, in our cohort, the detailed second trimester anatomy ultrasound had a sensitivity of 63.2% and specificity of 99.5% at detecting abnormal views on FE. We found high specificity and modest sensitivity in the prediction of abnormal FE by detailed second trimester anatomy ultrasound when both were performed by MFM. Our results reinforce the utility of FE performed by MFM even when the initial anatomy scan does not show suspected cardiac abnormalities.