Comparison of combined, biochemical and nuchal translucency screening for Down syndrome in first trimester in Northern Finland.
OBJECTIVE
To compare the efficacy of fetal nuchal translucency screening, maternal serum screening and combined screening for Down syndrome.


METHODS
A prospective study.


METHODS
University hospital and its public health care district in Northern Finland.


METHODS
A total of 35,314 women participated in the first-trimester screening for Down syndrome within the public healthcare system in 2002-08. There were 95 pregnancies involving Down syndrome. Serum samples were obtained from 35,314 women, nuchal translucency was measured in 27,144 pregnancies and full combined screening was performed in those pregnancies, including 76 involving Down syndrome.


METHODS
The adjusted estimated risk for Down syndrome was calculated using the Perkin Elmer AutoDELFIA® time-resolved fluoroimmunoassay kit for the measurement of pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin. Nuchal translucency was measured by trained personnel in a university or district hospital. Risk cut-off figures 1:250 and 1:300 at term were used.


METHODS
Differences in detection rate, false-positive rate, positive and negative predictive values between nuchal translucency screening, serum screening and combined screening.


RESULTS
Using the risk cut-off figure 1:250, the detection rates for serum screening, nuchal translucency screening and combined screening were 64.2, 64.5 and 72.4%, respectively and the false-positive rates were 7.8, 4.4 and 4.0%, respectively.


CONCLUSIONS
Combined screening is the method of choice for Down syndrome screening in Finland.
Department of Obstetrics and Gynecology, Oulu University Hospital, Oulu, Finland.
Sini
S
Peuhkurinen
Paivi
P
Laitinen
Timppa
T
Honkasalo
Markku
M
Ryynanen
Jaana
J
Marttala
D000328:Adult; D015415:Biomarkers / Q000097:blood; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood*; D004314:Down Syndrome / Q000175:diagnosis*; D005189:False Positive Reactions; D005260:Female; D005387:Finland; D006801:Humans; D062145:Maternal Serum Screening Tests; D048208:Nuchal Translucency Measurement; D011237:Predictive Value of Tests; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*; D011446:Prospective Studies; D018570:Risk Assessment
D015415:Biomarkers; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A