Cytogenetics Products of Conception (POC) Chromosome Analysis
88233; 88262, 88291
Indications for cytogenetic analysis on POC include: history of more than two miscarriages, abnormalities on ultrasound prior to pregnancy loss, confirmation of abnormal prenatal results or pregnancy loss after IVF. Abnormal POC cytogenetic results may preclude the need for extensive infertility evaluation. The diagnosis of a chromosome abnormality may be important in the management of future pregnancies.
Rule out chromosome abnormalities as a cause of miscarriage; determine fetal karyotype
Products of conception (POC)
3-4 mm POC specimen or 50-100 mg of each tissue; if possible, always include chorionic villi
Laboratory-provided screw-top tubes with sterile transport medium
Obtain POC’s using a sterile technique. Snip tissue using sterile scissors, etc. Cover specimen with sterile gauze to prevent contamination from airborne bacteria.
POC’s often contain large numbers of bacteria, so for a short period it is fine to keep the specimen at room temperature. For overnight or longer, it is better to place the specimen in the refrigerator to keep the bacteria from overgrowing the specimen.
In the absence of Integrated Genetics tubes, use any sterile screw-top container with tissue culture medium, Hanks Balanced Salt Solution or Earls and add antibiotics: Penicillin/Streptomycin (100 IU/ml/100 μg/ml) or Gentamycin (50 μg/ml). If the Integrated Genetics media has expired, please ship the specimen in the expired media, as it is preferable to any other types of tissue culture media. Do not place in formalin.
Preferred Specimen Types:
- Placenta – Tissue that contains chorionic villi (has 90% success rate)
- Umbilical Cord
- Skin – Take biopsy from under the arm or inner thigh. Avoid muscle, tendons or tough skin (such as heel). Sample size should be 3 mm minimum.
- Internal Organs – Liver, lung, kidney, thymus (have a 20% success rate)
- Whole Fetus – Please take a biopsy. Whole fetus samples are not accepted.
- Unacceptable Specimens – Specimens that have been fixed. We will not be able to culture cells as fixatives kill the cells. Common types of fixatives are formalin, formaldehyde and alcohol. Frozen specimens will not be able to be cultured as freezing kills the cells.
Causes for Rejection
Gross contamination; frozen tissue; specimen in fixative
Refrigerate. Do not freeze.