Ordering Recommendation

First-trimester screening test for trisomy 21 (T21, Down syndrome) and trisomy 18 (T18). Requires nuchal translucency measurement performed by an ultrasonographer certified by the Fetal Medicine Foundation (FMF) or the Nuchal Translucency Quality Review (NTQR). Refer to Maternal Screening, Sequential, Specimen #2, Alpha Fetoprotein, hCG, Estriol, and Inhibin A (3000148) for second-trimester screening test for T21, T18, and open neural tube defects. Risks provided in both first and second trimesters.

Mnemonic
MS SEQ1
Methodology

Quantitative Chemiluminescent Immunoassay

Performed

Sun-Sat

Reported

2-4 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation

Specimen must be drawn between 11 weeks, 0 days and 13 weeks, 6 days gestation. (Crown-Rump length (CRL) must be between 43-83.9 mm at time of specimen collection.)

Collect

Serum Separator Tube (SST) or Plain Red.

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer 3 mL serum to an ARUP Standard Transport Tube. (Min: 1 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Plasma. Hemolyzed specimens.

Remarks

Submit with Order: Patient's date of birth, current weight, number of fetuses present, patient's race, if the patient was diabetic at the time of conception, if there is a known family history of neural tube defects, if the patient has had a previous pregnancy with a trisomy, if the patient is currently smoking, if the patient is taking valproic acid or carbamazepine (Tegretol), if this is a repeat sample, and the age of the egg donor if in vitro fertilization.

In addition to the above: the date of ultrasound, the CRL measurement, the nuchal translucency (NT) measurement and the name and certification number of the sonographer is required.

NT must be measured when the CRL is between 38-83.9 mm.

The NT measurement must also be performed by an ultrasonographer that is certified by one of the following agencies: Fetal Medicine Foundation (FMF) or Nuchal Translucency Quality Review (NTQR). To avoid possible test delays for an ultrasonographer that is new to our database, please contact the genetic counselor at (800) 242-2787 extension 2141 prior to sending specimen.

If an NT is unobtainable, order Maternal Serum Screening, Integrated (ARUP test codes 3000147 (collect in first trimester) and 3000149 (collect in second trimester)), which can be interpreted without an NT value.

Stability

After separation from cells: Ambient: 72 hours; Refrigerated: 2 weeks; Frozen: 1 year (Avoid repeated freeze/thaw cycles.)

Reference Interval

By report

Interpretive Data

Refer to report.

Compliance Category

Laboratory Developed Test (LDT)

Note

The first specimen of a Sequential Maternal Serum Screening is used to measure PAPP-A and hCG. This test is used to screen for fetal risk of Down syndrome (trisomy 21) and trisomy 18. Final interpretative report, which also includes fetal risk for Open Neural Tube Defect (ONTD), will be available when the second specimen test results are complete.

Hotline History
N/A
CPT Codes

81508

Components
Component Test Code* Component Chart Name LOINC
0080920 Maternal Screen Interpretation 49586-1
0080922 Specimen 19151-0
0080926 Maternal Race 21484-1
0080927 Number of Fetuses 11878-6
0080932 Maternal Age At Delivery 21612-7
0081065 Nuchal Translucency (NT) 12146-7
0081068 MoM for PAPP-A 32123-2
0081069 Sonographer Certification # 49089-6
0081070 Sonographer Name 49088-8
0081071 Ultrasound Date 34970-4
0081074 MoM for NT 49035-9
0081158 Family History of Aneuploidy 32435-0
0081331 Best date to draw sample #2 by 33882-2
3000163 PAPP-A Maternal 48407-1
3000165 Smoking 64234-8
3000166 Crown Rump Length 11957-8
3000168 Nuchal Translucency (NT), Twin B
3000169 MoM for NT, Twin B 49035-9
3000170 Crown Rump Length, Twin B 11957-8
3000173 EER Maternal Serum, Sequential, Spcm1 11526-1
3000259 Patient's hCG, 1st Trimester 19080-1
3000260 hCG MoM, 1st Trimester 20465-1
3000263 Gestational Age Calculated at Collection 18185-9
3000264 Maternal Weight 29463-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • first trimester screen
  • Maternal Serum Sequential Screen
  • Sequential Screening
  • Serum Stepwise Sequential Screen
  • Stepwise Maternal Screen
  • Stepwise Sequential, Contingent
Maternal Screening, Sequential, Specimen #1, hCG, PAPP-A, NT