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Test Code SEQF Sequential Maternal Screening, Part 2, Serum

Reporting Name

Sequential Maternal Screen, Part 2

Useful For

Prenatal screening for Down syndrome and trisomy 18


Prenatal screening for  neural tube defects: (this is only applicable to Part 2 [second trimester] of the test)

-Part 2 (second trimester): alpha-fetoprotein

Testing Algorithm

The following are available in Special Instructions:

-Sequential Maternal Serum Screening Testing Process

-Prenatal Aneuploidy Screening and Diagnostic Testing Options Algorithm

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required

Sequential maternal screening is a 2-part test that includes a first-trimester sample (SEQU / Sequential Maternal Screening, Part 1, Serum) and a second-trimester sample (SEQF / Sequential Maternal Screening, Part 2, Serum). Do not order this test unless you have already ordered test SEQU / Sequential Maternal Screening, Part 1, Serum. If a standalone second-trimester screen is desired, order QUAD / Quad Screen (Second Trimester) Maternal, Serum.


Draw blood between 15 weeks, 0 days and 22 weeks, 6 days. Do not draw blood after performing amniocentesis, as that may lead to an artificially increased serum alpha-fetoprotein level and unreliable results.



Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1 mL

Collection Instructions: Spin down immediately.

Additional Information: Draw date is required.

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 7 days
  Frozen  90 days

Reference Values

An interpretive report will be provided. See Interpretation section for more details.

Day(s) and Time(s) Performed

Monday through Friday; 8 a.m.-4:30 p.m.

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


82105 (if appropriate)

82677 (if appropriate)

84702 (if appropriate)

86336 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SEQF Sequential Maternal Screen, Part 2 In Process


Result ID Test Result Name Result LOINC Value
29476 Recalculated Maternal Serum Screen 43995-0
29477 Collection Date 1 33882-2
29478 Maternal Birthdate 21112-8
29892 Calculated age at EDD 43993-5
29479 Maternal Weight 3141-9
29480 Maternal Weight 29463-7
29481 Insulin Dependent Diabetes 33248-6
29482 Black Race 32624-9
29493 Collection Date 2 33882-2
29888 IVF 47224-1
29485 Scan Date 34970-4
29886 Number of Fetuses 11878-6
29488 CRL Measure 1 11957-8
29489 CRL Measure 2 11957-8
29490 Chorions In Process
29893 GA on Collection by U/S Scan 1 11888-5
29894 GA on Collection by U/S Scan 2 11888-5
29491 NT 49035-9
29492 NT Twin B 49035-9
29887 PAPP-A 32123-2
29494 AFP 20450-3
29495 uE3 20466-9
29496 hCG, Total 20465-1
29497 Inhibin 35738-4
29500 Down Syndrome Screen Risk Estimate 43995-0
29501 Down Syndrome Maternal Age Risk 49090-4
29502 Trisomy 18 Screen Risk Estimate 43994-3
29503 Interpretation 59462-2
29504 Additional Comments 48767-8
29505 Recommended Follow Up 80615-8
29506 General Test Information 62364-5
32345 Other Information 48767-8

Method Name

Two-Site Immunoenzymatic (Sandwich) Assay