First‐trimester ultrasound detection of fetal heart anomalies: systematic review and meta‐analysis

ABSTRACT Objectives To determine the diagnostic accuracy of ultrasound at 11–14 weeks' gestation in the detection of fetal cardiac abnormalities and to evaluate factors that impact the detection rate. Methods This was a systematic review of studies evaluating the diagnostic accuracy of ultrasound in the detection of fetal cardiac anomalies at 11–14 weeks' gestation, performed by two independent reviewers. An electronic search of four databases (MEDLINE, EMBASE, Web of Science Core Collection and The Cochrane Library) was conducted for studies published between January 1998 and July 2020. Prospective and retrospective studies evaluating pregnancies at any prior level of risk and in any healthcare setting were eligible for inclusion. The reference standard used was the detection of a cardiac abnormality on postnatal or postmortem examination. Data were extracted from the included studies to populate 2 × 2 tables. Meta‐analysis was performed using a random‐effects model in order to determine the performance of first‐trimester ultrasound in the detection of major cardiac abnormalities overall and of individual types of cardiac abnormality. Data were analyzed separately for high‐risk and non‐high‐risk populations. Preplanned secondary analyses were conducted in order to assess factors that may impact screening performance, including the imaging protocol used for cardiac assessment (including the use of color‐flow Doppler), ultrasound modality, year of publication and the index of sonographer suspicion at the time of the scan. Risk of bias and quality assessment were undertaken for all included studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS‐2) tool. Results The electronic search yielded 4108 citations. Following review of titles and s, 223 publications underwent full‐text review, of which 63 studies, reporting on 328 262 fetuses, were selected for inclusion in the meta‐analysis. In the non‐high‐risk population (45 studies, 306 872 fetuses), 1445 major cardiac anomalies were identified (prevalence, 0.41% (95% CI, 0.39–0.43%)). Of these, 767 were detected on first‐trimester ultrasound examination of the heart and 678 were not detected. First‐trimester ultrasound had a pooled sensitivity of 55.80% (95% CI, 45.87–65.50%), specificity of 99.98% (95% CI, 99.97–99.99%) and positive predictive value of 94.85% (95% CI, 91.63–97.32%) in the non‐high‐risk population. The cases diagnosed in the first trimester represented 63.67% (95% CI, 54.35–7