Ordering Recommendation

For rapid detection of aneuploidy involving chromosomes 13, 18, 21, X, and Y. If the FISH results are abnormal, the specimen will reflex to chromosome analysis for mechanism determination. If the FISH results are normal, the specimen will reflex to genomic microarray.

New York DOH Approval Status

This test is not New York state approved. There are no New York state-approved laboratories available. Submit a Non-Permitted Laboratory Request Form (NPL) to the NYDOH prior to collection of specimen. If NPL is approved by NYDOH, and sample is received at ARUP, testing will be performed.

Specimen Required

Patient Preparation

Amniotic fluid.

Specimen Preparation

Do not freeze or expose to extreme temperatures. Transport 30 mL amniotic fluid in sterile centrifuge tubes. (Min: 15 mL)

Storage/Transport Temperature

Room temperature.

Unacceptable Conditions

Bloody specimens.


Ambient: 48 hours; Refrigerated: 48 hours; Frozen: Unacceptable


Fluorescence in situ Hybridization (FISH)




1-3 days
If reflexed: 1-2 weeks required for chromosome analysis or microarray

Reference Interval


Interpretive Data

Refer to report.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Compliance Category

Laboratory Developed Test (LDT)


Fluorescence in situ hybridization (FISH) is performed for aneuploidy of chromosomes X, Y, 13, 18, and 21. FISH will be performed on amniotic fluid. If FISH results are normal, sample will be reflexed to genomic microarray. If FISH results are abnormal, sample will be reflexed to chromosome analysis. Additional charges apply.

Maternal Cell Contamination: For maternal cell contamination studies in the event that FISH is normal and testing is reflexed to genomic microarray, please submit maternal blood and order Maternal Cell Contamination, Maternal Specimen (ARUP test code 0050608) accompanied by a test request form for the mother (this test is performed at no charge). For questions regarding ordering please contact ARUP's genetic counselor at (800) 242-2787 ext. 2141.

The FISH analysis does not detect structural chromosome abnormalities, mosaicism, and other numerical chromosome abnormalities (excluding X, Y, 13, 18, and 21). In addition, false-positive or -negative results, as well as maternal cell contamination, have been demonstrated in prenatal FISH analysis. The American College of Medical Genetics recommends that irreversible therapeutic action should not be initiated on the basis of FISH results alone.

The chromosome analysis studies involve culturing of living cells; therefore, turnaround times given represent average times which are subject to multiple variables.

A processing fee will be charged if this procedure is canceled at the client's request after the test has been set up or if the sample integrity is inadequate to allow culture growth.

This test must be ordered using Cytogenetic test request form #43098 or through your ARUP interface. Specimen and completed test request form, including clinical indication, must be received within 48 hours of collection. Submit the Patient History for Prenatal Cytogenetics form with the electronic packing list (https://ltd.aruplab.com/Tests/Pdf/65).

Hotline History


CPT Codes

88271 x5; 88275 x5: if reflexed to chromosome analysis add 88269; 88235; if reflexed to microarray add 81229; 81265 Fetal Cell Contamination (FCC)


Component Test Code* Component Chart Name LOINC
0097779 Chromosome FISH, Prenatal 55192-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • aCGH
  • AF
  • amnio
  • amniocytes
  • amniotic fluid
  • aneuploidy
  • array
  • CGH
  • CHR AF
  • Common trisomy FISH panel
  • Down syndrome
  • Edward
  • Insight
  • karyotype
  • multiple congenital anomalies
  • Patau
  • prenatal
  • prenatal FISH
  • T13
  • T18
  • T21
  • Trisomy 13
  • Trisomy 18
  • Trisomy 21
  • Turner syndrome
  • XO
Chromosome FISH, Amniotic Fluid with Reflex to Chromosome Analysis or Genomic Microarray