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HelpTest Code LAB3789 Sequential Maternal Screening, Part 2, Serum
Additional Codes
SQ: SEQBM
MAYO: SEQB
Ordering Guidance
Do not order this test unless test SEQA / Sequential Maternal Screening, Part 1, Serum has already been ordered.
If a standalone second-trimester screen is desired, order QUAD1 / Quad Screen (Second Trimester) Maternal, 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-step test that includes a first-trimester sample (SEQA / Sequential Maternal Screening, Part 1, Serum) and a second-trimester sample (SEQB / Sequential Maternal Screening, Part 2, Serum).
Necessary Information
Collection date is required.
Specimen Required
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions:
1. Collect blood between 15 weeks, 0 days and 22 weeks, 6 days. Do not collect blood after performing amniocentesis, as that may lead to an artificially increased serum alpha-fetoprotein level and unreliable results.
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
Secondary ID
113399Useful For
Prenatal screening for Down syndrome, neural tube defects, and trisomy 18
Identifying abnormal levels of alpha-fetoprotein in the second trimester
Testing Algorithm
For more information see Sequential Maternal Serum Screening Testing Algorithm.
Special Instructions
Method Name
Immunoenzymatic Assay
Reporting Name
Sequential Maternal Screen, Part 2Specimen 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 alpha-fetoprotein (AFP), unconjugated estriol (uE3), human chorionic gonadotropin (hCG), and inhibin A. These measurements are compared to median values for a given gestational age and a multiple of the median (MoM) is calculated for each. Then, results from both trimesters (part 1 and part 2) are entered into a multivariate algorithm that includes the mother's age to derive risk factors for Down syndrome, trisomy 18, and neural tube defects. An interpretive report will be provided.
AFP, beta hCG, uE3, and inhibin A assays are performed on the Beckman Access using an automated immunoenzymatic assays 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
81511
82105 (if appropriate)
82677 (if appropriate)
84702 (if appropriate)
86336 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| SEQB | Sequential Maternal Screen, Part 2 | 48800-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 29476 | Recalculated Maternal Serum Screen | 43995-0 |
| 601813 | Results Summary | 49092-0 |
| 29500 | Down Syndrome Screen Risk Estimate | 43995-0 |
| 29501 | Down Syndrome Maternal Age Risk | 49090-4 |
| 29502 | Trisomy 18 Screen Risk Estimate | 43994-3 |
| 602040 | Neural Tube Defect Risk Estimate | 49091-2 |
| 29491 | NT | 49035-9 |
| 601814 | NT MoM | 49035-9 |
| 29492 | NT Twin | 49035-9 |
| 601815 | NT Twin MoM | 49035-9 |
| 29887 | PAPP-A | 48407-1 |
| 601816 | PAPP-A MoM | 76348-2 |
| 29494 | AFP | 20450-3 |
| 601817 | AFP MoM | 23811-3 |
| 602805 | AFP MoM (14,0-14,6) | 23811-3 |
| 29495 | uE3 | 20466-9 |
| 601818 | uE3 MoM | 21264-7 |
| 29496 | hCG, Total | 83086-9 |
| 601819 | hCG, Total MoM | 23841-0 |
| 29497 | Inhibin | 35738-4 |
| 601820 | Inhibin MoM | 36904-1 |
| 29503 | Interpretation | 49092-0 |
| 29505 | Recommended Follow Up | 80615-8 |
| 29504 | Additional Comments | 48767-8 |
| 29477 | Specimen Collection Date 1 | 33882-2 |
| 29493 | Specimen Collection Date 2 | 33882-2 |
| 29478 | Maternal Date of Birth | 21112-8 |
| 29892 | Calculated age at EDD | 43993-5 |
| 29479 | Maternal Weight | 29463-7 |
| 29481 | Insulin Dependent Diabetes | 33248-6 |
| 29482 | Patient Race | 32624-9 |
| 601811 | Current cigarette smoking status | 72166-2 |
| 29485 | Scan Date | 34970-4 |
| 29488 | CRL | 11957-8 |
| 29489 | CRL Twin | 11957-8 |
| 29893 | GA on Collection by U/S Scan 1 | 11888-5 |
| 29894 | GA on Collection by U/S Scan 2 | 11888-5 |
| 29886 | Number of Fetuses | 11878-6 |
| 29490 | Chorions | 92568-5 |
| 29888 | IVF | 47224-1 |
| 601808 | Prev Down (T21) / Trisomy Pregnancy | 53826-4 |
| 601809 | Prev Pregnancy w/ Neural Tube Defects | 53827-2 |
| 601807 | Initial or repeat testing | 89231-5 |
| 601810 | Patient or father of baby has a NTD | 53827-2 |
| 601803 | Sonographer Name | 49088-8 |
| 602041 | Sonographer Code | No LOINC Needed |
| 601812 | Sonographer Reviewer ID | 49089-6 |
| 601804 | Physician Phone Number | 68340-9 |
| 29506 | General Test Information | 62364-5 |