Serum Integrated 1

CPT 84163
  • Down Syndrome
  • PAPP-A

Test Details


Screening test for open neural tube defects, Down syndrome, and trisomy 18

Special Instructions

For test inquiries, call CMBP genetic services at 800-345-4363. The following information must be provided: gestational age, date on which the patient was the stated gestational age, how gestational age was determined (LMP, EDD, US), patient's race, patient's weight, patient's date of birth, patient's insulin-dependent diabetic status, and the number of fetuses. Also indicate patient history (i.e. prior Down syndrome pregnancy, ultrasound anomalies). Complete information is necessary to interpret the test. Patient information may be provided to the laboratory using the Maternal Prenatal Screening requisition 0900. Testing provided from 10.0 to 14.0 weeks of gestation.


Serum integrated screening requires two specimens: one collected in the first trimester and one in the second trimester. This test number is for the first trimester portion of the test. Result interpretation will be provided only when the second trimester specimen is received and tested. This is a screening test. A positive result means that diagnostic testing may be offered to the pregnant woman to determine if a neural tube defect or chromosome abnormality is present.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.


Chemiluminescent immunoassay


Wald NJ, Watt HC, Hackshaw AK. Integrated screening for Down's syndrome based on tests performed during the first and second trimesters. N Engl J Med. 1999 Aug 12; 341(7):461-467. 10441601

Specimen Requirements

Information on collection, storage, and volume




3 mL

Minimum Volume

1 mL


Gel-barrier tube

Storage Instructions

Room temperature

Causes for Rejection

Gross hemolysis; gross lipemia; quantity not sufficient for analysis; improper specimen type


Collect in serum separator tube with gel barrier. Allow blood to clot, avoiding hemolysis. Separate serum from cells by centrifugation. Transport spun tube to testing laboratory.

Pour-off is not advised. Maternal serum specimens must be drawn prior to amniocentesis to avoid contamination with fetal blood.