Valor preditivo do resultado fetal da dopplervelocimetria de ducto venoso entre a 11ª e a 14ª semanas de gestação

PURPOSE: to study the value of Doppler velocimetry of the ductus venosus, between the 11th and 14th weeks of pregnancy, associated to the nuchal translucency thickness measurement, in the detection of adverse fetal outcome. METHODS: a transversal and prospective study in which a total of 1,268 fetuses were studied consecutively. In 56 cases, a cytogenetic study was performed on material obtained from a biopsy of the chorionic villus and, in 1,181 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 ductus venosus. Aiming at prevalence and accuracy indices, sensitivity, specificity, positive predictive value, negative predictive value, probability of false-positive, probability of false-negative, reason of positive probability and reason of negative probability were calculated and analyzed. RESULTS: from the total of 1,268 fetuses, 1,183 cases were selected for analysis. From this number, 1,170 fetuses were normal (98.9%) and 13 fetuses presented adverse outcome at birth (1.1%), including fetal death (trisomy 21 and 22) in two cases; genetic syndrome (Nooman) in one case; two cases of polymalformed fetuses; cardiopathy in three cases; and other structural defects in five cases. The prevalence of the modified ductus venosus (wave A zero/reverse) in the studied population was of 14 cases (1.2%), with a false-positive rate of 0.7%. CONCLUSIONS: there is a significant correlation between the alteration of the ductus venosus Doppler velocimetry and the thickness of the nuchal translucency as an ultrasonographic marker for the first trimester of gestation, in the detection of adverse fetal outcome, especially serious malformations. The ductus venosus was able to diminish the false-positive result in comparison to the isolated use of the nuchal translucency thickness, improving considerably the positive predictive value of the test.