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Test Code MAFP1 Alpha-Fetoprotein (AFP), Single Marker Screen, Maternal, Serum

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. Collection tubes should be centrifuged within 2 hours of collection.

Additional Information:

1. Draw blood between 15 weeks, 0 days and 22 weeks, 6 days.

2. 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 test, and both tests are performed at Mayo Clinic.

Useful For

Prenatal screening for open neural tube defect

Method Name

Two-Site Immunoenzymatic (Sandwich) Assay

Reporting Name

AFP Single Marker SCRN, Maternal, S

Specimen Type


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

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

Reject Due To

Gross hemolysis Reject
Gross lipemia OK

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.


An interpretive report will be provided.

Day(s) and Time(s) Performed

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

Performing 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. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
MAFP1 AFP Single Marker SCRN, Maternal, S 48802-3


Result ID Test Result Name Result LOINC Value
7058 Recalculated Maternal Serum Screen 32399-8
113146 Results Summary 32399-8
113147 Neural tube defect risk estimate 48803-1
10351 AFP 83073-7
113148 AFP MoM 23811-3
10356 INTERPRETATION 49092-0
10248 Additional comments 48767-8
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
RACE1 Patient race 21484-1
SMKNG Current cigarette smoking status 64234-8
10054 EDD by U/S scan 11781-2
7203 GA on collection by U/S scan 11888-5
7753 EDD by LMP 11779-6
7204 GA on collection by dates 11885-1
7830 GA used in risk estimate 21299-3
MULTF Number of Fetuses 55281-0
CHOR_ Number of Chorions 92568-5
IVFP IVF pregnancy 47224-1
PRNTD Prev Pregnancy w/ Neural Tube Defect 53827-2
PTNTD Patient or father of baby has a NTD 53827-2
INTL Initial or repeat testing 77202-0
DRPHN Physician Phone Number 68340-9