Ml. Brizot et al., MATERNAL SERUM PREGNANCY-ASSOCIATED PLASMA-PROTEIN-A AND FETAL NUCHALTRANSLUCENCY THICKNESS FOR THE PREDICTION OF FETAL TRISOMIES IN EARLY-PREGNANCY, Obstetrics and gynecology, 84(6), 1994, pp. 918-922
Objective: To determine if the risk for fetal trisomies during the fir
st trimester of pregnancy can be derived by combining data from matern
al serum pregnancy-associated plasma protein A (PAPP-A) and fetal nuch
al translucency thickness. Methods: pregnancy-associated plasma protei
n A was measured in samples from 87 singleton pregnancies with fetal c
hromosomal abnormalities (45 trisomy 21, 19 trisomy 18, eight trisomy
13, 11 sex chromosome aneuploidies, four triploidies) and 348 chromoso
mally normal controls at 10-13 weeks' gestation. Likelihood ratios for
trisomies 21, 18, and 13 in relation to PAPP-A, in multiples of the n
ormal median (MoM) for crown-rump length, were derived from the overla
pping gaussian frequency distribution curves for normal and abnormal p
regnancies. Results: In the chromosomally normal group, maternal serum
PAPP-A correlated significantly with fetal crown-rump length (r = 0.4
21, P < .0001). In the chromosomally abnormal group, the median PAPP-A
was significantly lower than in the normal controls. The respective m
edian values expressed in MoM for trisomies 21, 18, and 13 and other a
neuploidies were 0.5 MoM (90% confidence interval [CI] 0.09-1.67, z =
6.0, P < .001), 0.17 MoM (90% CI 0.06-1.45, z = 6.6, P < .001), 0.25 M
oM (90% CI 0.10-0.65 z = 4.5, P < .001), and 0.72 MoM (90% CI 0.09-2.4
8, z = 2.2, P < .05), respectively. There was no significant linear as
sociation between PAPP-A and fetal nuchal translucency thickness in ei
ther the chromosomally normal (r = -0.01, P = .89) or abnormal groups
(r = -0.19, P = .08). Conclusion: The risks for fetal trisomies at 10-
13 weeks' gestation can be derived by combining data on maternal age,
maternal serum PAPP-A, and fetal nuchal translucency thickness.