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Test Code XAFPM Quad Screen (Second Trimester) Maternal, Serum

Reporting Name


Useful For

Prenatal screening for open neural tube defect (alpha-fetoprotein only), Down syndrome (alpha-fetoprotein, human chorionic gonadotropin, estriol, and inhibin A) and trisomy 18 (alpha-fetoprotein, human chorionic gonadotropin, and estriol)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Specimen Required


Preferred: Red top

Acceptable: Serum gel

Specimen Volume: 1 mL

Collection Instructions:

1. Do not draw specimen after amniocentesis, as this could affect results.

2. Immediately spin down.

Additional Information:

1. For an assessment that includes neural tube defect results, gestational age must be between 15 weeks, 0 days and 22 weeks, 6 days.

2. Assessments for Down syndrome and Trisomy 18 only are available between 14 weeks, 0 days and 22 weeks, 6 days.

3. Initial or repeat testing is determined in the laboratory at the time of report and will be reported accordingly. To be considered a repeat test for the patient, the testing must be within the same pregnancy and trimester, with interpretable results for the same tests, and both tests are performed at Mayo Clinic.

4. Patient education brochure (T522) is available upon request.

Specimen Minimum Volume

0.75 mL

Specimen Stability Information

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

Reference Values


An AFP multiple of the median (MoM) <2.5 is reported as screen negative. AFP MoMs ≥2.5 (singleton and twin pregnancies) are reported as screen positive. 



Calculated screen risks <1/270 are reported as screen negative, risks ≥1/270 are reported as screen positive.



Calculated screen risks <1/100 are reported as screen negative, risks ≥1/100 are reported as screen positive.


An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; 5 a.m.-5 p.m.

Saturday; 6 a.m.-1 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

81511-Fetal congenital abnormalities, biochemical assays of four analytes (AFP, uE3, hCG [any form], DIA) utilizing maternal serum, algorithm reported as a risk score (may include additional results from previous biochemical testing)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
QUAD QUAD SCRN (2nd Tri) MATERNAL, S 48800-7


Result ID Test Result Name Result LOINC Value
7058 Recalculated Maternal Serum Screen In Process
3009 Specimen collection date 33882-2
7823 Maternal date of birth 21112-8
7834 Calculated age at EDD 43993-5
26717 Maternal Weight 29463-7
26718 Maternal Weight 29463-7
IDD Insulin dependent diabetes 44877-9
RACE Black race 32624-9
MULTF Number of Fetuses 55281-0
IVFP IVF pregnancy 47224-1
7816 Gestation (GA) by U/S 11888-5
7817 Date of U/S 34970-4
10054 EDD by U/S scan 11781-2
2907 Last Menstrual Period (LMP) 8665-2
7753 EDD by LMP 11779-6
7206 Gestation (GA) by dates 11885-1
7200 Date of estimate 80395-7
7201 Gestation (GA) by physical exam 11884-4
7202 Date of physical exam No LOINC Needed
7203 GA on collection by U/S scan 11888-5
7204 GA on collection by dates 11885-1
7205 GA on collection by physical exam 11884-4
7830 GA used in risk estimate 21299-3
10351 AFP 83073-7
10352 uE3 2250-9
10353 hCG, TOTAL 83086-9
10354 INHIBIN 2478-6
10334 Down syndrome screen risk estimate 43995-0
10335 Down syndrome maternal age risk 49090-4
10337 Trisomy 18 screen risk estimate 43994-3
10356 INTERPRETATION 49092-0
10248 Additional comments 55107-7
32284 Other Information 52535-2

Method Name

Immunoenzymatic Assay

Testing Algorithm

See Prenatal Aneuploidy Screening and Diagnostic Testing Options in Special Instructions


Second Trimester Maternal Screening Alpha-Fetoprotein (AFP)/QUAD Screen Patient Information (T595) is required in Special Instructions.