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Test Code MS1TRI AFP Maternal First Trimester Screen LAB2267


3 - 5 business days

Specimen Requirement

Specimen Type: Minimum 1 mL Serum

A comparison of the different maternal screening tests and complete collection and shipping instructions may be found here.
Patient Preparation: First trimester screening test for Down Syndrome and Trisomy 18, drawn between 10 weeks 0 days and 13 weeks 6 days gestation when Crown Rump Length (CRL) is 32-80 mm.
Collection Instructions: Dating by ultrasound Crown Rump Length (CRL). Serum sample drawn in the first trimester when the CRL is 32-80 mm. Incorrect dating will result in inaccurate risk assessment. Program brochures and patient consent forms are available for order.

Red Top Tube: centrifuge and transfer serum to a secondary tube. Serum Separator Tube: collect 4 - 6 mL and centrifuge.
Temperature and Stability: Refrigerated (2-8°C). Specimen must be received within 9 days of collection.
Unacceptable Conditions: Plasma. Samples not collected within the required gestational age range for the test requested.

Reference Values

MoM values for hCG and Papp-A; Risk Values for Down Syndrome and Trisomy 18; Screen Cutoff established for test; Interpretation/Recommended Action: Negative / No further action or Positive / Level II Ultrasound, counseling and consideration for diagnostic testing.

Useful For

Screen for Down Syndrome and Trisomy 18 risks in the first trimester of pregnancy. Does not include AFP for Open Neural Tube Defect (NTD) screening.

CPT Information



Quantitative Chemiluminescent Immunoassay