Objective: to study the value of Doppler velocimetry of the ductus venosus and of the umbilical artery and vein, in the screening for chromosomal abnormalities at 10-14 weeks of gestation. Patients and Methods: a total of 314 fetuses were studied consecutively. In 112 cases a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus, and in 202 cases the postnatal phenotype was used as a basis for the result. In addition to the routine ultrasonographic examination, all the fetuses were submitted to measurement of the nuchal translucency thickness and to Doppler velocimetry of the umbilical artery and vein, particularly of the ductus venosus. For statistical analysis the Fisher exact test and the Mann-Whitney test were used. Results: twenty-three cases of chromosomal abnormalities occurred. Of these abnormal cases, the ductus venosus blood flow during atrial contraction was absent (1 case) and reverse (22 cases), sensitivity was 92%. In the group of normal fetuses (289 cases), 6 evaluations demonstrated alterations in the Doppler of the ductus venosus (specificity of 97.6%, positive and negative predictive values of 76.7% and 93.3%, respectively); the false-positive rate was 2.4%. In reference to the umbilical vein and umbilical artery, there was no statistically significant difference between the abnormal and the normal group. Conclusion: The only parameter of Doppler velocimetry of the umbilical artery and vein which contributed to the detection of aneuploidies was the accidental discovery of the reverse blood flow in both vessels. Although our favorable results demonstrated that the Doppler velocimetry of the ductus venosus is effective in detecting aneuploidies, this conclusion, however, is preliminary and needs further investigation.
Doppler velocimetry; Ductus venosus; Umbilical artery; Umbilical vein; Chromosomal abnormalities; Prenatal diagnosis
