Diagnostic accuracy of prenatal ultrasound in coarctation of aorta: systematic review and individual participant data meta-analysis

objective: to determine the diagnostic accuracy of prenatal ultrasound (US) in detecting coarctation of aorta (CoA). methods: an individual participant data meta-analysis was performed to report the strength of association and diagnostic accuracy of different US signs in detecting CoA prenatally. MEDLINE, embase, and CINAHL were searched from January 2000 until november 2021. Individual participant-level data was obtained by two leading teams. PRISMA-IPD and PRISMA-DTA guidelines were used for abstracting data and the QUADAS-2 tool for assessing quality and applicability. the reference standard was CoA diagnosed after birth defined as narrowing of the aortic arch. the index test included the most commonly evaluated parameters on US both in B-mode and doppler. summary estimates of sensitivity, specificity, diagnostic odds ratio (DOR), and likelihood ratios were computed using hierarchical summary receiver-operating characteristics. results: the initial search yielded 72 studies of which 25 met the inclusion criteria (evaluation of fetuses with suspected CoA considered as isolated cardiac and/or great vessels disproportion with right dominance on US assessment). seventeen studies (640 fetuses) were included. at random effect logistic regression analysis, tricuspid/mitral valve ratio > 1.4 and >1.6, aortic isthmus/arterial duct ratio <0.7, hypoplastic arch (all p<0.001), aortic isthmus z-score <2 at sagittal (p=0.003) and 3-vessel view (p<0.001), pulmonary artery/ascending aorta ratio (p=0.048), bidirectional flow at the foramen ovale (p=0.012) and redundant foramen ovale (p=0.037) were independently associated with CoA. regarding diagnostic accuracy, tricuspid/mitral valve ratio >1.4 had a sensitivity of 72.6% (95%CI, 48.2-88.3), a specificity of 65.4% (95%CI, 46.9-80.2), and a DOR of 5.02 (95%CI, 1.82-13.9). the respective sensitivity/specificity figures for pulmonary artery/ascending aorta ratio >1.4, aortic isthmus z-score <-2 at sagittal and aortic isthmus at 3-vessel views were 75.0% (95%CI, 61.1-86.0)/39.7% (95%CI, 27.0-53.4), 47.8% (95%CI, 14.6-83.0)/87.6% (95%CI, 27.3-99.3) and 74.1% (95%CI, 58.0-85.6)/62.0% (95%CI, 41.6-78.9). Hypoplastic arch had a sensitivity of 70.0% (95%CI, 42.0-88.6), a specificity of 91.3 (95%CI, 78.6-96.8), and a DOR of 24.9 (95%CI, 6.18-100). continuous parameters were independently associated with CoA (all, p<0.001) but all had low-moderate diagnostic yield, same as multivariate models. Conclusions: Several prenatal ultrasound parameters are associated with an increased risk for postnatal CoA. however, diagnostic accuracy is only moderate, even when combined. this article is protected by copyright. all rights reserved.