RESUMO
OBJECTIVE: To evaluate the efficiency of the measurement of fetal nuchal translucency (FNT) and ductus venosus Doppler examination (DV Doppler) as a screening tool for chromosomal abnormalities. METHODS: FNT measurement and DV Doppler wereperformed in 950 pregnancies between 11(+0)~13(+6) weeks' gestation. Chromosomal analysis was done when FNT was more than 3 mm and DV Doppler showed absent flow or reversed flow. The numbers of cases with increased FNT and abnormal DV Doppler were counted in the groups of abnormal and normal karyotype. RESULTS: Data were available in 912 pregnancies. 11 pregnancies showed abnormal karyotype (1.2%). In the 11 cases with abnormal karyotype,increased FNT was found in 8 cases with 72.7% sensitivity and abnormal DV Doppler was found in 5 cases with 45.4% sensitivity. In the 901 cases withnormal karyotype, increased FNT was found in 33 cases with 96.3% specificity and abnormal DV Doppler was found in 12 cases with 98.7% specificity. Positive predictive value was 19.5% in cases of increased FNT, 29.4% in cases of abnormal DV Doppler, and 44.4% in cases of increased FNT and abnormal DV Doppler both. CONCLUSION: There is no improvement in general screening for chromosomal abnormalities when FNT measurement and DV Doppler were performed together. But better specificity and positive predictive value for chromosomal abnormalities were found.