Alpha-Fetoprotein (AFP), Maternal Serum for Open Spina Bifida

Additional Information:

UFHPL Epic order code: LAB2184J

Special Instructions

This test screens for open spina bifida. This test does not screen for Down syndrome or trisomy 18. The following information must be provided: gestational age, date on which the patient was the stated gestation age, how gestational age was determined (LMP, EDD, US), patient’s weight, patient’s date of birth, patient’s race (white, black, other), and insulin-dependent diabetic status. Also indicate relevant patient history, such as prior neural tube defects, ultrasound anomalies, or previous maternal serum screening during this pregnancy. Complete information is necessary to interpret the test. Patient information may be provided to the laboratory using the Maternal Prenatal Screening request form (0900). Specimens must be collected before amniocentesis.

Open spina bifida screening is offered for gestational ages 15.0 to 23.9 weeks. The optimal gestational age for open spina bifida screening is 16.0 to 18.9 weeks.>

CPT Code(s):


Specimen Requirements:

Type: Serum

Note: No isotopes should be administered to the patient within 24 hours prior to the venipuncture.

Container/Tube: Gel-barrier tube, no thrombin additive

Collection: Separate serum from cells. Avoid hemolysis. Send the complete specimen in its original tube. Do not pour-off.

Sample Volume: 3 mL

Minimum Volume: 0.4 mL (Repeat testing is not possible with this specimen volume.)

Storage: Store specimens at room temperature.

Stability (collection to time of analysis/testing):

  • Ambient: 7 days
  • Refrigerated: 14 days
  • Frozen: 14 days
  • Freeze/Thaw cycles: Stable (x3)
Rejection Criteria:

  • Gross hemolysis
  • Gross lipemia
  • Quantity not sufficient (QNS)


This is a screening test that is used for open neural tube defects. It detects up to 80 percent of open spina bifida and 90 percent of anencephaly. This test does not provide screening for down syndrome or trisomy 18.


Immunochemiluminometric assay (ICMA)