Prenatal diagnosis using the triple test

Abstract

Methods: A screening study performed on 2,803 pregnant women using the "triple test" is reported.

Results: Nine hundred and twenty-one had a high prior risk, having > 35 years while, after the screening, only 201 women had a positive test at risk higher than 1:270, and underwent to amniocentesis. The detection rate (DR) for all abnormalities was 91% while for Down's syndrome (DS) it was 87.5% and for neural tube defects 85.5%. Foetal abnormalities were detected in 20 cases (1:10) while 181 were false positive cases (6.5%), of which 151 for DS (5.4%). False negative were observed only in 2 cases within 2,339 at term pregnancies.

Conclusions: The authors retain that high DR is related to the exactness of determination of gestation age calculated by scan and to the homogeneity of the examined population.