CPT® Code 81508

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

The CPT® Code 81508 refers to a specific laboratory test that assesses the risk of fetal congenital abnormalities through biochemical assays of two proteins found in maternal serum. This test measures the levels of pregnancy-associated plasma protein A (PAPP-A) and human chorionic gonadotropin (hCG) in the blood of pregnant individuals. The primary purpose of this test is to evaluate the risk for certain chromosomal abnormalities, notably trisomy 18 and trisomy 21, which is commonly known as Down syndrome. The test is most effective when conducted during a specific window of gestation, particularly between 10 weeks and 3 days to 13 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 sample to generate a risk score. This score is crucial for healthcare providers in making informed decisions regarding further diagnostic testing or monitoring during the pregnancy.