Nuchal translucency and major congenital heart defects in fetuses with normal karyotype: a meta‐analysis

Objective To pool published data regarding the sensitivity and specificity of nuchal translucency ( NT ) in the diagnosis of major congenital heart defects ( CHDs ) in fetuses with normal karyotype. Methods MEDLINE and Scopus searches using combinations of the terms ‘nuchal’ and ‘cardiac*’ were complemented by perusal of references of the retrieved articles and an additional automated search using the ‘search for related articles’ function on PubMed . Only fetuses with normal karyotype and major CHDs were analyzed. Weighted estimates were made and summary receiver–operating characteristics curves were constructed. Results The analysis included 20 studies (205 232 fetuses; 537 cases with major CHDs ). The pooled sensitivity and specificity of NT > 95 th centile for diagnosis of major CHDs was 44.4% (95% CI , 39.5–49.5) and 94.5% (95% CI , 94.4–94.6), respectively. The pooled sensitivity and specificity of NT > 99 th centile was 19.5% (95% CI , 15.9–23.5) and 99.1% (95% CI , 99.1–99.2), respectively. For the subgroup of studies in which NT was measured by Fetal Medicine Foundation‐certified operators, the pooled sensitivity and specificity of NT > 95 th centile was 45.6% (95% CI , 39.6–51.7) and 94.7% (95% CI , 94.6–94.9), respectively. The corresponding estimates for NT > 99 th centile were 21.0% (95% CI , 16.5–26.1) and 99.2% (95% CI , 99.2–99.3). The pooled positive likelihood ratio for NT > 99 th centile was 30.5 (95% CI , 24.3–38.6). There was high across‐studies heterogeneity for most estimates. Conclusion Approximately 44% of chromosomally normal fetuses with CHDs have NT > 95 th centile and 20% have NT > 99 th centile. However, there is high heterogeneity across studies, which largely remains even in subgroup analyses of studies of apparently similar design, potentially indicating the presence of some residual unidentified bias. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.