OBJECTIVE: To evaluate fetal nuchal translucency, ductus venosus, nasal bone and maternal age > 35 years by means of aneuploidy screening between the 12th and 14th gestational weeks in a high-risk population. MATERIALS AND METHODS: Prospective, observational study involving 92 pregnant women at 12-14 gestational weeks, who were submitted to chorionic villus sampling because of high risk for trisomy 21 based on the measurement of nuchal translucency thickness (17.4%) or on maternal age > 35 years (78.3%). Before the chorionic villus sampling, fetal nuchal translucency thickness was measured, ductus venosus flow was evaluated and the nasal bone was identified. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for tests in parallel and in sequence. RESULTS: Chromosomal abnormalities were found in 12 fetuses (13.5%); 7 (58.3%) were positive for trisomy 21. The nasal bone was present in all cases with chromosomal abnormalities. Isolated nuchal translucency, ductus venosus or maternal age showed low sensitivity (41.67-58.33%) and low positive predictive value (10-45.45%). Combined nuchal translucency + ductus venosus + maternal age showed the best results (100% sensitivity; 6.49% specificity; 14.29% positive predictive value; 100% negative predictive value). CONCLUSION: In pregnant women with >35 years of age, combined nuchal translucency + ductus venosus have showed the highest sensitivity as an indication for invasive procedure.

Keywords: Nuchal translucency measurement, Ductus venosus, Nasal bone, Maternal age, Trisomy