Fetal Aneuploidy Screening

Fetal aneuploidy screening is a prenatal FISH analysis which identifies numerical abnormalities of chromosomes 13, 18, 21, X, and Y.

Indications for Testing

  • Advanced maternal age
  • Ultrasound abnormalities

Testing Methodology

Prenatal FISH analysis for numerical chromosomal abnormalities is performed on interphase nuclei. This assay yields preliminary results only. Chromosomal analysis is also performed on all specimens submitted for fetal aneuploidy screening.

Specimen Requirements

Amniotic fluid: Collect 20 – 25 cc in a 50 ml sterile conical centrifuge tube.

Chorionic villi: Collect 15 – 20 mg villi in a T-25 tissue culture flask containing sterile tissue culture media.

Turnaround Time

3 - 4 days

CPT Codes

88271, 88275, 88291

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