Evaluation of first-trimester ultrasound screening strategy for fetal congenital heart disease.

Objective: To assess the performance of a standardized first-trimester ultrasound screening strategy for fetal congenital heart disease (CHD).

Methods: This was a large retrospective study involving 74 839 consecutive mixed-risk pregnancies (77 396 fetuses). Routine ultrasound scans at 11 + 0 to 13 + 6 weeks' gestation were performed in a single center from January 2015 to June 2023. All fetuses were examined using a predefined standardized ultrasound scanning strategy with adjustment of imaging parameters, which included assessment of the fetal heart. The ultrasound results (e.g. extracardiac congenital malformations), ultrasound markers (e.g. nuchal translucency thickening, reversed a-wave in the ductus venosus and tricuspid regurgitation), follow-up, genetic tests and diagnostic results were recorded and analyzed.

Results: In total, there were 831 cases of CHD, with an incidence of 1.07% (831/77 396). In the first-trimester scan, 590 fetuses were diagnosed with CHD, but four were confirmed as normal in later examinations. In addition, 245 cases were missed. The detection rate was 70.52%, with a sensitivity, specificity, false-positive rate and false-negative rate of 70.52%, 99.99%, 0.01% and 29.48%, respectively. In fetuses with negative ultrasound markers and no extracardiac malformations, the detection rate of CHD was 45.79% (185/404). There were 281 cases that underwent karyotyping and chromosomal microarray (245 fetuses) or whole-exome sequencing (36 fetuses). In total, 38.79% (109/281) had a positive genetic test result. There were 273/831 CHD cases associated with extracardiac malformations. The abnormal image patterns and abnormal features of each view in the scanning strategy were summarized.

Conclusions: Ultrasound screening for fetal CHD in the first trimester of pregnancy enables earlier prenatal diagnosis and consultation. The standardized ultrasound screening strategy used in this study had a high detection rate for fetal CHD in the first trimester. Our proposed fetal heart screening strategy shows promising effectiveness for early diagnosis of CHD and we recommend its use. It is important to note, however, that first-trimester ultrasound screening for fetal CHD should not replace fetal echocardiography in the second trimester. © 2025 International Society of Ultrasound in Obstetrics and Gynecology.