Nuchal Translucency and the Risk of Congenital Heart Disease

Abstract

II.

Risk of critical congenital heart defects by nuchal translucency norms

“…14,15 Our findings that fewer than 5% of CCHDs had an NT >3.5 mm and that fewer than 10% were detected by the 99th percentile cutoff are lower estimates than others have observed. 11,13,28,29 These findings are consistent with previous studies that have demonstrated CCHD detection rates to be lower in low risk or general populations and lower with better CCHD ascertainment, both of which are characteristics of this study. 11,13,28,29 Given that our observed prevalence of 2.5 CCHD per 1000 births is similar to that reported across these same subtypes of CCHDs in both national and California specific studies, we believe that our ascertainment was robust.…”

“…11,13,28,29 These findings are consistent with previous studies that have demonstrated CCHD detection rates to be lower in low risk or general populations and lower with better CCHD ascertainment, both of which are characteristics of this study. 11,13,28,29 Given that our observed prevalence of 2.5 CCHD per 1000 births is similar to that reported across these same subtypes of CCHDs in both national and California specific studies, we believe that our ascertainment was robust. 30,31 Our period of ascertainment extended through 1 year of age, whereas others have included mostly only CCHDs that were diagnosed at birth.…”

“…[4][5][6][7][8] Over the past decade, first-trimester nuchal translucency (NT) measurement has been used increasingly for prenatal detection of chromosomal abnormalities and has been associated with CCHDs in pregnancies with and without aneuploidy. [9][10][11][12] Although an enlarged NT has been associated with CCHDs (defined by either an NT measurement percentile for crownrump-length [CRL] or by a specific NT measurement in millimeters), [9][10][11]13 having an NT measurement of 3.5 mm is the most commonly applied cutoff at which fetal echocardiography is recommended, based on guidelines of the American College of Obstetricians and Gynecologists. 14,15 Here we evaluate how well an NT cutoff of 3.5 mm performs in comparison with NT percentile by CRL for identifying pregnancies carrying fetuses with CCHDs in a large, diverse population-based sample of live-born singleton pregnancies (n ¼ 76,089) with complete CCHD ascertainment.…”

Effect of Increased Body Mass Index on First-Trimester Ultrasound Examination for Aneuploidy Risk Assessment

“…8 An increased nuchal-translucency measurement is also useful for predicting other abnormalities such as congenital heart disease. [11][12][13] Therefore, obtaining the nuchal-translucency measurement is an important aspect of prenatal care. Our study has demonstrated that, although nuchal translucency can be visualized as optimally in the obese compared with the nonobese patient, there is a significant increase in the resources needed to obtain an optimal view.…”

“…9,10 In addition, an increased nuchal-translucency measurement has been associated with fetal cardiac defects, leading to the recommendation of following up increased nuchal-translucency measurements with fetal echocardiography. [11][12][13] Secondary to the importance of obtaining the nuchaltranslucency measurement and visualizing the nasal bone, we proposed a study to investigate the effect of increased BMI on the first-trimester ultrasound examination for aneuploidy risk assessment.…”