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HelpTest Code LAB3788 Sequential Maternal Screening, Part 1, Serum
Additional Codes
SQ: SEQAM
MAYO: SEQA
Ordering Guidance
When part 1 is negative, part 2 must be completed in order to receive an interpretable result. If collecting a second-trimester specimen is expected to be difficult, order first-trimester screening instead (1STT1 / First Trimester Maternal Screen, Serum).
If a stand-alone neural tube defect risk assessment is desired, order MAFP1 / Alpha-Fetoprotein (AFP), Single Marker Screen, Maternal, Serum.
Additional Testing Requirements
Sequential maternal screening is a 2-part test that includes a first-trimester sample (this test) and a second-trimester sample (SEQB / Sequential Maternal Screening, Part 2, Serum).
Necessary Information
Approval to send specimen for first-trimester screening is required and may take up to 5 business days to complete. Nuchal translucency (NT) measurements are only accepted from NT-certified sonographers. Do not send specimen to Mayo Clinic Laboratories if the sonographer is not NT-certified or before completing the application process. See Maternal Screening: Sonographer Approval Process. Complete the NT/CRL Data for First Trimester/Sequential Maternal Screening.
Specimen Required
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. The ultrasound and blood draw must be completed within a gestational window of 10 weeks, 0 days and 13 weeks, 6 days, which corresponds to a crown-rump length range of 31 to 80 mm.
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Forms
First Trimester/Sequential Maternal Screening Patient Information (T593) is required.
Secondary ID
113398Useful For
First-trimester prenatal screening for trisomy 21 (Down syndrome) and trisomy 18 (Edwards syndrome)
Testing Algorithm
Sequential maternal screening is a 2-step test, with first- and second-trimester components. It requires a nuchal translucency measurement and blood collection in the first trimester. If the result from part 1 indicates a risk for Down syndrome that is higher than the screen cutoff, the screen is completed, and a report is issued. If the results from part 1 are negative, an additional blood collection in the second trimester is required (SEQB / Sequential Maternal Screening, Part 2, Serum). If the second specimen is not received for sequential screening, the results are uninterpretable, and no maternal risk will be provided.
For additional information see Sequential Maternal Serum Screening Testing Algorithm.
Special Instructions
Method Name
Immunoenzymatic Assay
Reporting Name
Sequential Maternal Screen, Part 1Specimen Type
SerumSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 7 days | |
| Frozen | 90 days | ||
| Ambient | 7 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
An interpretive report will be provided.
Method Description
This test includes measuring the nuchal translucency (NT) and pregnancy-associated plasma protein A (PAPP-A). The NT and PAPP-A are compared to median values for a given gestational age and a multiple-of-the-median (MoM) is calculated for each. The MoM results are entered into a multivariate algorithm that includes the mother's age to derive risk factors for Down syndrome and trisomy 18. If the calculated risks exceed the screen cutoff, the results are reported and the screen is ended. If the results from the first part of screening fall below the screen cutoff, the results are held until the second sample is analyzed. PAPP-A is performed on the Beckman Access using an automated immunoenzymatic assay with paramagnetic separation and chemiluminescent detection.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
4 to 6 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84163
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SEQA | Sequential Maternal Screen, Part 1 | 49086-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 29451 | Recalculated Maternal Serum Screen | 43995-0 |
| 601802 | Results Summary | 50679-0 |
| 29469 | Down Syndrome Screen Risk Estimate | 43995-0 |
| 29470 | Down Syndrome Maternal Age Risk | 49090-4 |
| 29471 | Trisomy 18 Screen Risk Estimate | 43994-3 |
| 29468 | PAPP-A | 48407-1 |
| 601799 | PAPP-A MoM | 76348-2 |
| NT1 | NT | 33069-6 |
| 601800 | NT MoM | 49035-9 |
| NTTB1 | NT Twin | 33069-6 |
| 601801 | NT Twin MoM | 49035-9 |
| 29472 | Interpretation | 49586-1 |
| 29474 | Recommended Follow Up | 80615-8 |
| 29473 | Additional Comments | 48767-8 |
| 29452 | Specimen Collection Date | 33882-2 |
| 29453 | Maternal Date of Birth | 21112-8 |
| 29890 | Calculated Age at EDD | 43993-5 |
| 29454 | Maternal Weight | 29463-7 |
| 29455 | Maternal Weight | 29463-7 |
| DIAB1 | Insulin Dependent Diabetes | 33248-6 |
| RACE_ | Patient Race | 32624-9 |
| SMKN2 | Current cigarette smoking status | 72166-2 |
| SNDT1 | Scan Date | 34970-4 |
| CRL1A | CRL | 11957-8 |
| CRL2A | CRL Twin | 11957-8 |
| 29891 | GA on Collection by U/S Scan | 11888-5 |
| FET1 | Number of Fetuses | 11878-6 |
| CHOR1 | Chorions | 92568-5 |
| IVF1 | IVF | 47224-1 |
| PRHIX | Prev Down (T21) / Trisomy Pregnancy | 53826-4 |
| PRNTA | Prev Pregnancy w/ Neural Tube Defect | 53827-2 |
| PTNTA | Patient or father of baby has a NTD | 53827-2 |
| INTL2 | Initial or repeat testing | 86955-2 |
| SONOM | Sonographer Name | 49088-8 |
| SNCD1 | Sonographer Code | No LOINC Needed |
| SONO1 | Sonographer Reviewer ID | 49089-6 |
| DRPH2 | Physician Phone Number | 68340-9 |
| 29487 | General Test Information | 62364-5 |