CHROMOSOME ANALYSIS:

AMNIOTIC FLUID

Amniotic fluid is the most common source of fetal cells for prenatal diagnosis. The procedure called amniocentesis is performed during the second trimester, preferably at 15 to 17 weeks of gestation. Banding level 500-550; 2 banded karyotypes, analysis of 15 metaphases from separate colonies or 20 metaphases from monolayers.

REASONS FOR REFERRAL

·         Advanced Maternal Age

·         Previous offspring with chromosomal abnormality

·         Family history of chromosomal abnormality

·         Increased risk to the fetus based on the maternal serum prenatal screening tests

·         Fetal abnormality detected on ultrasonography

TESTING METHODOLOGY

·         Amniocytes are cultured as (1) colonies on cover glasses which enables in situ harvesting, and (2) as monolayers in T-type flasks.

SPECIMEN REQUIREMENTS

·         20-30 ml of amniotic fluid in sterile centrifuge tubes or bottles (discard the first 2 cc collected; syringes not acceptable).

·         The Prenatal Diagnostic Information Form, Alpha-fetoprotein Requisition and Consent Form, and a Cytogenetic Laboratory Test Requisition must accompany the specimen. For shipping and handling information, refer to Cytogenetic Specimen Instructions.

TURNAROUND TIME: 9 to 14 days

CPT CODES: 88235, 88267, 88280, 82106, 88291