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Is nuchal translucency measurement useful as a screening test for major cardiac abnormalities?
Author(s) -
LeeTannock A.,
Cincotta R. B.,
Chan F. Y.,
Hawthorne F.
Publication year - 2001
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1046/j.1469-0705.2001.abs21-6.x
Subject(s) - medicine , nuchal translucency measurement , nuchal translucency , population , fetus , obstetrics , abnormality , fetal echocardiography , pregnancy , prenatal diagnosis , genetics , environmental health , psychiatry , biology
Aim: To determine if measurement of nuchal translucency is a useful predictor of major cardiac abnormality in a low risk population. Methods: A total of 1888 fetuses (1849 patients) were scanned in our department as part of a nuchal translucency screening programme between 1 January 1999 and 31 December 2000. Those pregnancies with abnormal karyotypes were excluded from this study. Follow up was obtained and cases of major isolated cardiac anomalies were identified. Results: There were 35 fetuses that had normal chromosomes and a nuchal translucency measurement greater than the 95th centile. Nine of these had a nuchal translucency measurement greater than 3.5 mm, and 12 of these had a nuchal translucency measurement greater than 4.5 mm. In our study population, there were six fetuses diagnosed with an isolated major cardiac defect (3.2/1000 births). All of these fetuses had normal nuchal translucency measurements less than the 95th centile and none came from the group with increased nuchal translucency. In one case, the diagnosis was made at 12 weeks, three were diagnosed at the 18–20 weeks morphology scan and two were diagnosed after birth. Discussion: Several studies have demonstrated a link between an increased nuchal translucency measurement and cardiac defects in fetuses with normal chromosomes. Hyett suggests that increased nuchal translucency at 10–14 weeks will detect 55% of major cardiac abnormalities. According to the risk estimates from this paper, we estimate that there should have been 1.5 cases of cardiac anomalies in the low risk group whilst there should have been two cardiac anomalies in the fetuses above the 95th centile. We found six major cardiac anomalies in the low risk group and none in the higher risk group. However, the difference between the estimated and observed number of cases was not statistically significant due to the small size of our screening study. We would recommend larger studies to determine the efficacy of nuchal translucency as a screening tool for detection of cardiac anomalies. Detailed cardiac imaging at the 18–20 weeks morphology scan should continue to be performed on all patients regardless of the nuchal translucency measurement in the first trimester.