CPT® Code 81509

Fetal congenital abnormalities, biochemical assays of three proteins (PAPP-A, hCG [any form], DIA), utilizing maternal serum, algorithm reported as a risk score

The CPT® Code 81509 refers to a specific laboratory test that assesses the risk of fetal congenital abnormalities through biochemical assays of three proteins found in maternal serum. This test measures the levels of pregnancy-associated plasma protein A (PAPP-A), human chorionic gonadotropin (hCG) in any form, and Inhibin A Dimer (DIA). The primary purpose of this blood test is to evaluate the risk for certain chromosomal abnormalities, notably trisomy 18 and trisomy 21, which is also known as Down syndrome. The test is most effective when conducted during a specific window of gestation, particularly between 15 weeks and 22 weeks and 6 days. During this period, the sensitivity of the test results is maximized, allowing for a more accurate risk assessment. The blood sample required for this test is obtained through a procedure known as venipuncture, which is separately reportable. The serum collected is then analyzed using a quantitative chemiluminescent immunoassay, a sophisticated laboratory technique that quantifies the proteins in the serum to generate a risk score based on the algorithm utilized in the analysis.