F. Debieve et al., Multiple screening for fetal Down's syndrome with the classic triple test,dimeric inhibin A and ultrasound, GYNECOL OBS, 49(4), 2000, pp. 221-226
The aim of the study was to determine whether inhibin combined with ultraso
und improves the classic second trimester triple test. Eighteen Down's synd
rome and 200 euploid pregnancies were included. Maternal serum ci-fetoprote
in (AFP), human chorionic gonadotrophin (hCG), and estriol (E-3), measured
between 15 and 20 weeks' gestation by radioimmunoassay, were retrieved. Inh
ibin A was tested with a specific two-monoclonal-antibody ELISA. Ultrasound
was performed between 15 and 25 weeks' gestation: femur length, nuchal thi
ckness and morphological abnormalities were assessed. Statistical analysis
used a multivariate discriminant analysis. Except for the classic triple te
st parameters, only inhibin and the standard deviation score (SDS) for femu
r length allowed us to make a statistically significant distinction between
euploid and Down's syndrome pregnancies. For a 5% false-positive rate, the
classic triple test sensitivity was 61%. When E-3 was replaced with inhibi
n A, the sensitivity increased to 77.8% and to 66.7% with SDS femur length.
Combining hCG, AFP, SDS femur length and inhibin A gave a sensitivity of 6
6.7% for a false-positive rate of 2.5%. In conclusion, the classic triple t
est can be more significantly improved by replacing E-3 with inhibin than b
y including ultrasound. However, a combination of ultrasound and inhibin en
hances both the sensitivity and specificity of the test. In Down's syndrome
screening, the biological parameters improve sensitivity while ultrasound
is a better indication of specificity. Copyright (C) 2000 S. Karger AG, Bas
el.