Re-evaluation of risk for Down syndrome by means of the combined test in pregnant women of 35 years or more.
OBJECTIVE
Evaluation of combined test in pregnant women 35 years of age and over to detect fetal Down syndrome.


METHODS
The study population included 408 pregnant women of 35 years and over, who requested the combined test (nuchal translucency, PAPP-A, free beta hCG, maternal age, cut-off 1:250) before deciding whether to undergo amniocentesis.


RESULTS
The test was positive in 66 women who then requested amniocentesis for fetal karyotype determination; the other women had a negative test and declined amniocentesis. False-positives increased with maternal age from 6.6% at 35 years to about 50% at 40 to 41 and 100% in women over 41. Six cases of Down syndrome and two cases of trisomy 18 were detected. Not a single case of Down syndrome or trisomy 18 was missed, and other chromosome abnormalities were detected as well.


CONCLUSIONS
The application of the combined test reduced the need for invasive testing to only 14% of the studied pregnant population, without missing any of the fetuses with trisomy 21 or 18.
Centini
Giovanni
G
Prenatal Diagnosis Centre, Chair of Obstetrics and Gynecology, Department of Pediatrics, Obstetrics, and Reproductive Medicine, University of Siena, Siena Italy. centini@unisi.it
Rosignoli
Lucia
L
Scarinci
Renato
R
Faldini
Elisa
E
Morra
Carmina
C
Centini
Gabriele
G
Petraglia
Felice
F
D000328:Adult; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008423:Maternal Age; D008499:Medical Records; D009333:Neck / Q000000981:diagnostic imaging / Q000196:embryology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D012307:Risk Factors; D014314:Trisomy; D014463:Ultrasonography
D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A