Chromosome FISH, Amniotic Fluid with Reflex to Chromosome Analysis or Genomic Microarray
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.

Fluorescence in situ Hybridization
1-3 days
If reflexed: 1-2 weeks required for chromosome analysis or microarray
New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Time SensitiveTime Sensitive
Cytogenetic Test Request Form Recommended (ARUP form #43098)Cytogenetic Test Request Form Recommended (ARUP form #43098)
ARUP Consult®
Disease Topics
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 
Reference Interval
Interpretive Data
Refer to report.
Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

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 Microarray Genomic, Maternal Confirm (ARUP test code 2002369) 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 (
Hotline History
CPT Code(s)
88271 x5; 88275 x5; 88291: if reflexed to chromosome analysis add 88269;  88235;  88291; if reflexed to microarray add 81229; 81265 Fetal Cell Contamination (FCC)
Component Test Code*Component Chart NameLOINC
0097779Chromosome FISH, Prenatal55192-9
* 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