Chromosome Analysis, amniotic fluid
Collection Restrictions
Gestational age should be at least 14 weeks, but preferably 15-20 weeks
Collection Requirements
Source: amniotic fluid
Container: sterile clear centrifuge tubes
Volume: breakdown based on ordered tests
- Chromosome analysis: 15-20 mL
- FISH analysis: 4 mL
- Alpha-Fetoprotein: 1 mL
- Toxoplasmosis, CMV, HSV, etc: 1 mL for each test
- Microarray or NGS:
- 15 mL if ordered with chromosome analysis
- 25 mL if ordered without chromosome analysis
- AND 2-3 mL maternal blood in EDTA lavender vacutainer
Special Instructions
- Transport at room temperature; avoid fluctuating temperatures (hot or cold)
- Cap tubes tightly
- Specimen must be processed within 24 hours of collection
- Contact Genetics for collection materials
- Use the Prenatal and Pregnancy Loss Cytogenetics Requisition
Turn Around Time
14 days
Availability
Routine
Lab Processing Instructions
Specimen: amniotic fluid
Room temperature
Performing Laboratory
Genetics
Adele Hall Lab Section
Cytogenetics
Instrumentation/Methodology
Primarily In situ cell culture. The cells are processed by exposure to colcemid and hypotonic solution, then fixed. Slides are prepared and metaphase cells are GTG banded. Chromosomes analysis and image captured are performed on a computerized imaging system.
Additional Information
Indications for testing: advanced maternal age (>35 years of age); Previous pregnancy with a chromosome abnormality; Parent carrying a known translocation; Abnormal ultrasound findings; Abnormal NIPS
Reference Ranges
See interpretive report
CPT
88267, 88280, 88235