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SerumIntegratedScreenSM is a two-part test that screens for fetal Down syndrome, trisomy 18 and open neural tube defects. Between 10 weeks / 3 days and 13 weeks / 6 days (10.4-13.9 weeks, CRL= 39-84mm), pregnancy-associated plasma protein (PAPP-A) is measured in a maternal blood sample. Then, patients are directed to come back between 15 weeks / 0 days and 21 weeks / 6 days (15.0-21.9 weeks) for a second blood draw. Alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol (uE3) and dimeric Inhibin-A are measured on the second sample. SerumIntegratedScreen combines these measurements to provide a single risk assessment in the second trimester.

Test Details


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


Enzyme immunoassay (EIA)

Pregnancy Week

0–13 Weeks
14–21 Weeks

Specimen Requirements


Serum; whole blood, or dried blood spot


Serum:  2 mL serum, in SST for both first and second trimester specimens.

Whole Blood:  7 mL in SST or 10 mL in red-top tube for both first and second trimester specimens.

Dried Blood Spot: fill a minimum of three circles completely with blood. Please Note: If prenatal carrier screening for cystic fibrosis is ordered in conjunction with first trimester screening all six circles should be filled.


Serum: Serum separator tube (SST)

Whole Blood: Serum separator tube (SST) or red-top tube

Dried Blood Spots collected on Integrated Genetics provided filter paper/test requisition.


Avoid hemolysis. Send complete specimen in the original tube. Do not pour off.

Special Instructions

Blood:Whole:  allow to clot, centrifuge (15 minutes at 1,500 rpm) to prevent hemolysis.

Dried Blood Spot:  Please Note: Only the first trimester integrated sample (Part 1 of SerumIntegratedScreen) can be collected on dried blood spot filter paper. For the second trimester sample of SerumIntegratedScreen, please send whole blood or serum (see specimen requirements listed). Second trimester dried blood spot samples will be rejected and cancelled. Please Note: Please do not send dried blood spot samples for second trimester samples of SerumIntegratedScreen.

Causes for Rejection

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

Storage Instructions

Store at room temperature

Additional Information


SerumIntegratedScreen requires two specimens: one collected in the first trimester and one in the second trimester. This test 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 whether a neural tube defect or chromosome abnormality is present.



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