Sequential 1

Casandra

Casandra Test Code LC65453Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 017700CPT Codes 81508, 84163, 84702

Also known as: Down Syndrome, Nuchal Translucency (NT), PAPP-A

Clinical Use

Order Test

Use

Screening test for open neural tube defects, Down syndrome, and trisomy 18

Special Instructions

Client must provide fetal nuchal translucency (NT) measurement and crown rump length measurement. The NT measurement must be performed by a sonographer credentialed by the Fetal Medicine Foundation or other equivalent entity. Additional required information includes the patient's race, weight, date of birth, insulin-dependent diabetic status, and the number of fetuses. Complete information is necessary to interpret the test and can be provided using the Maternal Prenatal Screening requisition 0900.

Limitations

Sequential screening requires two specimens: one collected in the first trimester and one in the second trimester. This test number is for the first trimester portion only. Result interpretation for the first trimester is provided only for screen-positive specimens. Final results require the second trimester specimen. A positive result indicates that further diagnostic testing may be necessary to determine the presence of a neural tube defect or chromosome abnormality.

Test Details

Methodology

Immunoassay (CLIA)

Biomarkers

hCG

Analyte

hCG Value • Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

PAPP-A

Analyte

PAPP-A Value • Concentration / Level • Quantitative (Continuous) (e.g., copies/mL, % expression)

LOINC Codes

Result Codes

49586-1
11957-8
34970-4
49089-6
18185-9
43993-5
21484-1
29463-7
11878-6
12146-7
49035-9
19080-1
32166-1
48407-1
76348-2
43995-0
49090-4
43994-3
47223-3
77202-0
11502-2

Result Turnaround Time

2-5 days

Specimen

Serum

Volume

3 mL

Minimum Volume

1 mL

Container

Gel-barrier tube

Collection Instructions

Collect in serum separator tube with gel barrier. Allow blood to clot, avoiding hemolysis. Separate serum from cells by centrifugation. Transport spun tube to testing laboratory. Pour-off is not advised. Maternal serum specimens must be drawn prior to amniocentesis to avoid contamination with fetal blood.