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Important Note

Please accompany specimen with Iowa Maternal Screen Test Request Form.


Incorrect information, especially incorrect dating, will result in inaccurate risk assessment.  The following information is required for test interpretation: Patient demographic information and dating for pregnancy (ultrasound information) should match the information submitted with the first sample test.  Supply current weight.  Test cannot be performed on multiples.  Detection rates: 85% Down syndrome 80% Trisomy 18 85% Neural tube defects  False positive Rate: 2.6% without NT 1.9% with NT

Performing Laboratory

State Hygienic Laboratory (SHL) Coralville

Specimen Requirements

Second sample of a 2-part test drawn between 15 and 20 weeks 6 days gestation.  Requires that the first integrated sample was submitted in the 1st trimester.  Screening test for DS, T18, and Open NTD determined using a combination of 1st and 2nd trimester markers with or without a 1st trimester nuchal translucency (NT) measurement.


Container/Tube: Gold-top serum separator or red top

Specimen: 1 mL serum

Transport Temperature:  Refrigerated with cold pack

Stability:  Refrigerated (2-8 C) and specimen must be received with 9 days of collection

Collection Instructions:  Dating by ultrasound crown rump length (CRL).  Serum sample drawn in the 2nd trimester between  15 weeks 0 days to 20 weeks 6 days.  The date range this sample is to be collected is included in the integrated, 1st trimester draw report.  Incorrect dating will result in inaccurate risk assessment.

Specimen Minimum Volume

1 mL of serum

Reference Values

CMoM values for AFP(NTD screen), hCG, Estriol, Inhibin, and Papp-A risk values for Down Syndrome and Trisomy 18 screen cutoff established for test interpretation/Recommended Action:

Negative/ No further action

Positive/ Level II Ultrasound, counseling, and consideration for diagnostic testing.


Final report will be titled Maternal Screen Integrated, since the results come from both sample 1 and 2.

Day (s) Test Set Up

Monday through Friday

Analytic Time

3-5 business days

Reject Due To


Samples not collected within the required gestational age range drawn for the test requested.


CPT Coding

AFP 82105

hCG 84702

Estriol 82677

Inhibin A 86336

Papp-A 84163


Quantitative Chemiluminescent Immunoassay