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Laboratory Test Directory

Chromosome Analysis, Fetal Fluid (Updated)


Name Method Department Units
Fetal Fluid Chromosome Analysis Cell Culture
Chromosomal analysis

Specimen Requirements

Body fluid

Container Type Container Size Specimen Volume

Sterile container

N/A 20 mL-35 mL

Room temperature - 24 hour(s)

Specimen Preparation

  • Do not add fixative
  • Do not freeze
  • Do not centrifuge
  • Do not refrigerate
  • Keep at room temperature

Reasons for Rejection

  • Fixed specimen
  • Frozen specimen
  • Delayed or improper handling
  • Not received within specified time frame


Submission of a completed Prenatal Genetic Test Requisition Form is required -- please specify the source/type of collected fetal fluid on the form. To obtain the form, please call Cytogenetics Lab at (614) 722-5321.

This test is used to evaluate fetal chromosomes for numerical and gross structural abnormalities (e.g. translocations, inversions) when obtaining amniotic fluid sample is not feasible. Common indications for study include fetal structural abnormalities detected on ultrasound exam accompanying oligohydramnios (e.g. cystic hygroma, ascites, bladder outlet obstruction).

For this test, fetal cells contained in the fetal fluid sample will be cultured, then cultured metaphase cells will be used to perform chromosome analysis. Cells from 15 colonies wil be evaluated for this test, unless poor cell growth prohibits. Extended mosaicism study (performed with extra charges) can also be ordered, which evaluates chromosomes in additional colonies to study for low-level mosaicism for chromosome abnormality. Please note that depending on the number of viable cells contained in the submitted fluid, cell culture and chromosome analysis result may take longer than quoted turnaround time, or cell culture may fail and no chromosome analysis result may be available.

Please collect minimum of 15 mL fetal fluid in a non-toxic, sterile container. Transport the sample at room temperature and send to the laboratory within 24 hours from collection time. DO NOT freeze the sample.

  • If Aneuploidy FISH Screen for common aneuploidies (chromosomes 13, 18, 21, X and Y; see test code: GEN3) is also ordered, submit additional 5-10 mL fluid.
  • If infectious disease qualitative PCR is also ordered, submit 2-3 mL additional fluid. Although direct (unspun) fluid is always preferred, supernatant fluid can also be used as alternate sample for these tests.
  • If Prenatal Microarray Analysis is also desired, please submit maternal sample (4 mL blood in EDTA tube) for maternal cell contamination study.
  • If additional testing on cultured cells is also ordered (e.g. Send-out cultured cells to another laboratory), submit additional 5-10 mL?fluid and call Cytogenetics Lab to speak with a laboratory genetic counselor to coordinate. For molecular genetic testing to be performed on cultured cells, submission of maternal sample (4 mL blood in EDTA tube) is also recommended to perform maternal cell contamination study.

CPT Code

  • 88235
  • 88267
  • 88280