Chromosome Analysis - Prenatal and Pregnancy Loss

TEST NAME:   Chromosome Analysis - Prenatal and Pregnancy Loss
Also known as:   Cytogenetics, Karyotyping by G-banding

INDICATIONS FOR PRENATAL CHROMOSOME ANALYSIS:

  • Advanced maternal age (> 35 years of age)
  • Previous pregnancy with a chromosome abnormality
  • Parent carrying a known translocation
  • Abnormal ultrasound findings
  • Abnormal first or second trimester screening test

INDICATIONS FOR PREGNANCY LOSS CHROMOSOME ANALYSIS:

At least 10-15% of all recognized pregnancies are miscarried. Chromosome abnormalities cause more than 50% of first trimester losses and 15% of second trimester losses.1

  • History of multiple spontaneous abortions without evidence of a clear reason for the loss
  • Previous pregnancy with or family history of a chromosome abnormality
  • Parent carrying a known translocation

TEST INFORMATION:   Standard methodology is used for G-banded chromosome analysis. It is our protocol to perform Amniotic Fluid AFP (AF-AFP) on amniotic samples concurrently unless the gestational age is greater than 22 weeks 6 days in which case AChE is completed instead of AF-AFP. In most situations if AF-AFP is positive, AChE will be sent out and will be an added cost.

ADVANTAGES:

  • Detects aneuploidy, triploidy, structural rearrangements (balanced and unbalanced), and large-scale deletions and duplications
  • Whole genome analysis
  • Establishes chromosomal orientation of genetic material

LIMITATIONS:

  • Requires mitotic (dividing) cells, which can be problematic with pregnancy loss specimens
  • Limited resolution as compared to newer technologies such as microarray
  • Unable to provide gene-specific information

COMPLEMENTARY TESTING:

Chromosome Analysis identifies a chromosomal rearrangement, such as a balanced translocation, in 5-8% of individuals with recurrent pregnancy loss.2,3


REQUIRED FORMS:   Prenatal and Pregnancy Loss Test Request Form

OTHER FORMS:


SPECIMEN REQUIREMENTS: 

  • Amniotic Fluid: 15 - 20 ml amniotic fluid in sterile tubes
    • PLUS FISH: collect an additional 5 ml (20-25 ml total needed to perform Chromosome Analysis and FISH)
    • PLUS Prenatal Microarray: collect an additional 10-15 ml (25-35 ml total needed to perform Chromosome Analysis, FISH, and Microarray)
  • Chorionic Villi Sampling (CVS): 10-20 mg in (sterile) villi in tissue culture media
  • Products of Conception (POC): 0.5-1.0 cm3 (sterile)  fetal tissue and/or villi in tissue culture media
    • Preferred fetal tissue sample sites include buttocks or thigh. If fetal tissue is not available placental villi can be utilized. Separate villi from maternal blood and deciduas to reduce the chance for maternal cell contamination.

    • Amniotic fluid if IUFD or therapeutic abortion, if possible.


SPECIMEN COLLECTION & SHIPPING


CPT CODES:

  • Amniotic Fluid: 88235(x2), 88269, 88280(x2), 88285
  • Additional (Send Out) Testing on Amniotic Fluid:
    • AChE: 82013, 82106, 82143, 82664
    • AF-AFP: 82106
    • Cytomegalovirus (CMV) PCR: 87496
    • Parvovirus PCR: 87798
    • Toxoplasma PCR: 87798
  • Chorionic Villi Sampling (CVS): 88235(x2), 88261, 88280(x2), 88285(x3)
  • Product of Conception (POC): 88233(x2), 88261, 88280(x2), 88285(x3)

PRICING:   Contact the laboratory billing staff for current costs.


TURN-AROUND-TIME:   Results are typically available in 7-10 days on amniotic fluid and CVS; 10-14 days on POC.


LINKS and REFERENCES:

1. Gardner RJM, Sutherland GR. Chromosome Abnormalities and Genetic Counseling. 3rd ed. New York: Oxford University Press; 2004.
2. Braekeleer MD, Dao TN. Cytogenetic sudies in couples experiencing repeated pregnancy losses. Hum Reprod. 5(5):519-528, 1990.
3. Harger JH, Archer DF, Marchese SG, Muracca-Clemons M, Garver KL. Etiology of Recurrent Pregnancy Losses and Outcome of Subsequent Pregnancies. Obstet Gynecol. 62(5):574-581, 1983.


 v14.1

CAP Accredited
CAP Graphic

CLIA Accredited
CMS Centers for Medicare & Medicaid Services Logo

contact us
Phone:  402-559-5070 
1-800-656-3937 x95070
Fax:  402-559-7248
humangenetics@unmc.edu

;