CPT® Code 81420

Fetal chromosomal aneuploidy (eg, trisomy 21, monosomy X) genomic sequence analysis panel, circulating cell-free fetal DNA in maternal blood, must include analysis of chromosomes 13, 18, and 21

The CPT® Code 81420 refers to a specific laboratory test designed to analyze fetal chromosomal aneuploidy through genomic sequence analysis of circulating cell-free fetal DNA found in maternal blood. This test is particularly focused on detecting chromosomal abnormalities such as trisomy 21, which is associated with Down syndrome, monosomy X linked to Turner syndrome, and other aneuploidies. The analysis must include chromosomes 13, 18, and 21, which are critical in identifying these conditions. The procedure involves obtaining a blood sample from the mother, which is then tested for the presence of fetal DNA fragments. This is accomplished using advanced techniques such as targeted sequencing and single-nucleotide polymorphism analysis. The test is indicated for certain maternal risk factors, including advanced maternal age, abnormal ultrasound findings, and previous pregnancies affected by aneuploidy. A positive result from this test may lead to further genetic testing options, such as chorionic villus sampling or amniocentesis, to confirm the presence of chromosomal abnormalities.