OP28.09: Increased nuchal translucency and congenital heart defects: is there any association?

Detection of congenital heart defect (CHD) is one of the most important challenges in prenatal diagnosis. The literature reported an incidence of CHD between 1.7% and 3.5% live birth. In chromosomally normal fetuses an increased nuchal translucency (NT) is associated with a variety of cardiac defects and rare genetic syndrome. The aim of this multicentric observational study was to analyzed a relationship between increased NT and CHD in a low-risk population. Between September 2006 and September 2008, we enrolled 8366 women without risk factors or pregnancy complications. We performed a NT measurement (between 11 and 13 + 6 gestational weeks). Women with an increased risk (> 1:300) were offered invasive testing for fetal karyotyping, then they underwent to echocardiography at 16 weeks of gestation. We calculated the sensitivity of increased NT (> 95th) for cardiac defects. 8366 fetuses were analyzed. The pregnancies lost to follow-up were 30. The prevalence of CHD in our population was 2.06. Fetuses with increased NT and normal kariotype were 147 (1.75%). We found 11/147 CHD (7.48%): 3 CHD were associated with syndromes. Sensibility and specificity were respectively 45%, 97.8% with a positive likelihood ratio of 20.45. NT screening for major cardiac defects appears to be superior to the traditional indications for specialist echocardiography, including family history of cardiac defects, maternal diabetes mellitus, or the injections of teratogens. An echocardiography at 16 weeks of gestation may be required for fetuses with increased NT to complete heart examination.