Retrospective study evaluating the performance of a first-trimester combined screening for trisomy 21 in an Italian unselected population.
OBJECTIVE
to assess the performance of a combined first-trimester screening for trisomy 21 in an unselected Italian population referred to a specialized private center for prenatal medicine.


METHODS
a retrospective validation of first-trimester screening algorithms [risk calculation based on maternal age and nuchal translucency (NT) alone, maternal age and serum parameters (free β-hCG and PAPP-A) alone and a combination of both] for fetal aneuploidies evaluated in an unselected Italian population at Artemisia Fetal-Maternal Medical Centre in Rome. All measurements were performed between 11(+0) and 13(+6) weeks of gestation, between April 2007 and December 2008.


RESULTS
of 3,610 single fetuses included in the study, we had a complete follow-up on 2,984. Fourteen of 17 cases of trisomy 21 were detected when a cut-off of 1:300 was applied [detection rate (DR) 82.4%, 95% confidence interval (CI) 64.2-100; false-positive rate (FPR) 4.7%, 95% CI 3.9-5.4; false-negative rate (FNR) 17.6%, 95% CI 0-35.8%].


CONCLUSIONS
in our study population the detection rate for trisomy 21, using the combined risk calculation based on maternal age, fetal NT, maternal PAPP-A and free β-hCG levels, was superior to the application of either parameter alone. The algorithm has been validated for first trimester screening in the Italian population.
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Francesco
F
Padula
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Pietro
P
Cignini
Scientific Direction, Biostatistical Unit, Regina Elena National Cancer Institute, Rome, Italy.
Diana
D
Giannarelli
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Cristiana
C
Brizzi
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Claudio
C
Coco
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Laura
L
D'Emidio
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Elsa
E
Giorgio
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Maurizio
M
Giorlandino
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Lucia
L
Mangiafico
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Marialuisa
M
Mastrandrea
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Vincenzo
V
Milite
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Luisa
L
Mobili
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Cinzia
C
Nanni
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Raffaella
R
Raffio
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Cinzia
C
Taramanni
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Roberto
R
Vigna
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Alvaro
A
Mesoraca
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Domenico
D
Bizzoco
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Ivan
I
Gabrielli
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Gianluca
G
Di Giacomo
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Maria Antonietta
MA
Barone
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Antonella
A
Cima
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Francesca Romana
FR
Giorlandino
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Sabrina
S
Emili
Department of Genetics and Molecular Biology, Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Marina
M
Cupellaro
Department of Prenatal Diagnosis, Altamedica-Artemisia Fetal-Maternal Medical Centre, Rome, Italy.
Claudio
C
Giorlandino
Down Syndrome; SCA-Test; first trimester screening; nuchal translucency