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Sequential 1

CPT [MAAA: 81508] or 84163; 84702
Synonyms
  • Down Syndrome
  • Nuchal Translucency (NT)
  • PAPP-A

Test Details

Methodology

Chemiluminescent immunoassay

Result Turnaround Time

2 - 5 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Related Documents

Use

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

Special Instructions

For test inquiries, call CMBP genetic services at 800-345-4363. 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. The sonographer's credential/certification number must be provided. The following information also must be provided: patient's race, patient's weight, patient's date of birth, patient's insulin-dependent diabetic status, and the number of fetuses. Also indicate patient history (i.e. prior Down syndrome pregnancy, ultrasound anomalies). Complete information is necessary to interpret the test. Patient information may be provided to the laboratory using the Maternal Prenatal Screening requisition 0900. Serum testing is provided from 10.0 to 14.0 weeks of gestation. NT can be assessed when the CRL is 45 to 84 mm.

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 of the test. Result interpretation for the first trimester portion will be provided only for screen-positive specimens. Result interpretation for all others will be provided only when the second trimester specimen is received and tested. This is a screening test. A positive result means that diagnostic testing may be offered to the pregnant woman to determine if a neural tube defect or chromosome abnormality is present.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

References

Wald NJ, Rudnicka AR, Bestwick JP. Sequential and contingent prenatal screening for Down syndrome. Prenat Diagn. 2006 Sep; 26(9):769-777.16821246

Specimen Requirements

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.

Stability Requirements

Temperature

Period

Room temperature

7 days

Refrigerated

14 days

Frozen

14 days

Freeze/thaw cycles

Stable x3

Storage Instructions

Room temperature

Causes for Rejection

Gross hemolysis; gross lipemia; quantity not sufficient for analysis; improper specimen type

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
017700 Sequential 1 017859 Results N/A
017700 Sequential 1 017701 Test Results: 49586-1
017700 Sequential 1 017703 Submit Part 2 Sample Using N/A
017700 Sequential 1 017704 Crown Rump Length mm 11957-8
017700 Sequential 1 018064 Crown Rump Length Twin B mm 11957-8
017700 Sequential 1 017705 CRL Scan 34970-4
017700 Sequential 1 018065 CRL Scan Twin B 34970-4
017700 Sequential 1 018021 Sonographer ID# 49089-6
017700 Sequential 1 017706 Gest.Age on Collection Date weeks 18185-9
017700 Sequential 1 017708 Maternal Age at EDD yr 43993-5
017700 Sequential 1 017709 Race 21484-1
017700 Sequential 1 017710 Weight lbs 29463-7
017700 Sequential 1 017711 Number of Fetuses 11878-6
017700 Sequential 1 017712 Nuchal Translucency (NT) mm 12146-7
017700 Sequential 1 017713 Nuchal Translucency MoM 49035-9
017700 Sequential 1 018063 NT Twin B mm 12146-7
017700 Sequential 1 018070 NT MoM Twin B 49035-9
017700 Sequential 1 018173 Additional US N/A
017700 Sequential 1 017362 hCG Value IU/mL 19080-1
017700 Sequential 1 017716 hCG MoM 32166-1
017700 Sequential 1 018217 PAPP-A Value ng/mL 48407-1
017700 Sequential 1 017718 PAPP-A MoM 76348-2
017700 Sequential 1 018087 Down Syndrome 43995-0
017700 Sequential 1 018089 Down Syndrome 49090-4
017700 Sequential 1 018090 Trisomy 18 43994-3
017700 Sequential 1 018091 Trisomy 18 47223-3
017700 Sequential 1 017702 Down Syndrome Interpretation 49586-1
017700 Sequential 1 017724 Trisomy 18 Interpretation 49586-1
017700 Sequential 1 017288 Comments: 77202-0
017700 Sequential 1 017854 Note: N/A
017700 Sequential 1 511933 PDF 11502-2
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017859
Result Code NameResults
UofM
Result LOINCN/A
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017701
Result Code NameTest Results:
UofM
Result LOINC49586-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017703
Result Code NameSubmit Part 2 Sample Using
UofM
Result LOINCN/A
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017704
Result Code NameCrown Rump Length
UofMmm
Result LOINC11957-8
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018064
Result Code NameCrown Rump Length Twin B
UofMmm
Result LOINC11957-8
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017705
Result Code NameCRL Scan
UofM
Result LOINC34970-4
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018065
Result Code NameCRL Scan Twin B
UofM
Result LOINC34970-4
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018021
Result Code NameSonographer ID#
UofM
Result LOINC49089-6
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017706
Result Code NameGest.Age on Collection Date
UofMweeks
Result LOINC18185-9
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017708
Result Code NameMaternal Age at EDD
UofMyr
Result LOINC43993-5
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017709
Result Code NameRace
UofM
Result LOINC21484-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017710
Result Code NameWeight
UofMlbs
Result LOINC29463-7
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017711
Result Code NameNumber of Fetuses
UofM
Result LOINC11878-6
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017712
Result Code NameNuchal Translucency (NT)
UofMmm
Result LOINC12146-7
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017713
Result Code NameNuchal Translucency MoM
UofM
Result LOINC49035-9
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018063
Result Code NameNT Twin B
UofMmm
Result LOINC12146-7
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018070
Result Code NameNT MoM Twin B
UofM
Result LOINC49035-9
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018173
Result Code NameAdditional US
UofM
Result LOINCN/A
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017362
Result Code NamehCG Value
UofMIU/mL
Result LOINC19080-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017716
Result Code NamehCG MoM
UofM
Result LOINC32166-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018217
Result Code NamePAPP-A Value
UofMng/mL
Result LOINC48407-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017718
Result Code NamePAPP-A MoM
UofM
Result LOINC76348-2
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018087
Result Code NameDown Syndrome
UofM
Result LOINC43995-0
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018089
Result Code NameDown Syndrome
UofM
Result LOINC49090-4
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018090
Result Code NameTrisomy 18
UofM
Result LOINC43994-3
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code018091
Result Code NameTrisomy 18
UofM
Result LOINC47223-3
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017702
Result Code NameDown Syndrome Interpretation
UofM
Result LOINC49586-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017724
Result Code NameTrisomy 18 Interpretation
UofM
Result LOINC49586-1
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017288
Result Code NameComments:
UofM
Result LOINC77202-0
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code017854
Result Code NameNote:
UofM
Result LOINCN/A
Order Code017700
Order Code NameSequential 1
Order Loinc
Result Code511933
Result Code NamePDF
UofM
Result LOINC11502-2