Increased nuchal translucency and congenital heart defects in euploid fetuses

Abstract

Objective: To determine the utility of the first-trimester fetal nuchal translucency (NT) thickness in the prediction of fetal cardiac malformations. Design: Retrospective study. Setting: Department of Obstetrics and Gynecology and Medical Genetics, University of Szeged. Methods: The pre-and postnatal course and outcome, and the relationship between the first-trimester fetal NT thickness and fetal congenital heart defects (CHDs) in 4309 pregnancies ended up with birth or therapeutic abortion between January 1998 and June 2000 were registered. Prenatal care included first-and second-trimester fetal sonography at weeks 10-13 and 18-20, respectively. Results: 4251 births and 58 first-and second-trimester therapeutic abortions due to lethal congenital malformations or chromosomal abnormalities were recorded. Altogether 209 (4.9%) congenital malformations were detected, 39 (18.7%) of which were heart defects with normal karyotype. At birth, 151 congenital malformations were diagnosed, 34 of them were known prenatally. The prevalence of CHDs was 9 per 1000 pregnancies. The measurement of fetal NT thickness was available in 35 of the 39 fetuses with heart defects: it was !3 mm in 18 (51.4%) and <3 mm in 17 (48.6%). A sensitivity of 51.4% was found at a cutoff of 3 mm. Conclusions: An increased NT thickness in chromosomally normal fetuses was found to be highly associated with CHDs and identified in more than half of the affected cases. Furthermore, an increased NT of !3 mm can be regarded a selection criterion for early second-trimester targeted fetal echocardiography and for increased fetal and neonatal surveillance. #

Nuchal translucency and cystic hygroma colli in screening for fetal major congenital heart defects in a series of 12 910 euploid pregnancies

“…The second type are studies reporting the prevalence of severe CHD in a general population of fetuses in which the NT was measured; these studies were mostly intended to evaluate the value of NT measurements as a means of screening for CHD (Table 6)11–22.…”

“…The largest series studied to date are those reported by Nicolaides et al 3. Other studies have also shown that there is a relationship between NT and CHD4–24. However, conflicting results have been obtained concerning the suitability of NT measurements for CHD screening.…”

Early Fetal Echocardiography at the Time of 11+0–13+6 Weeks Scan

“…Orvos et al 14 found a significant association with left heart lesions and septal defects, however, Makrydimas 15 in the multicenter study based on 637 CHDs did not support this hypothesis.…”

“…13 There are various policies reported regarding NT cut-off as an indicator for fetal echocardiography ranging between 95th percentile (2.2 mm to 2.8 mm depending on CRL measurements) to 99th percentile equal to 3.5 mm. 14,15 Detection rates for CHD using 3.5 mm NT cut-off varies significantly from 3.7 to 40%, depending on the published series. 16,17 Though Hyett and colleagues obtained very good sensitivity basing on NT screening their prevalence of CHDs was low (1.7/1000).…”

“…4 As a response some authors suggested to decrease NT cutoff to 95th percentile to improve sensitivity however at the end it resulted in strongly increased false positive rate and unnecessary referrals to tertiary centers. 14 Maiz et al proved that risk of CHD based on NT measurement differs depending on co-existence of reverse or positive a-wave in DV velocimetry and it was three fold higher or two fold lower respectively. 13 Favre et al examined euploid fetuses with diagnosed CHDs and increased NT measurements with coexisting abnormal ductus venosus velocimetry.…”