Ordering Guidance

This test does not detect balanced chromosome rearrangements, such as Robertsonian or other reciprocal translocations, inversions, or balanced insertions. These abnormalities may be identified by chromosome analysis; see CHRAF / Chromosome Analysis, Amniotic Fluid or CHRCV / Chromosome Analysis, Chorionic Villus Sampling.

If the reason for testing or specimen type received indicates a fetal demise, this test will be canceled and CMAPC / Chromosomal Microarray, Autopsy, Products of Conception, or Stillbirth will be added and performed as the appropriate test.

Additional Testing Requirements

A maternal blood sample is requested when ordering this test (see PPAP / Parental Sample Prep for Prenatal Microarray Testing, Blood); the PPAP test must be ordered under a different order number than the prenatal specimen.

A paternal blood sample is desired but not required (see PPAP / Parental Sample Prep for Prenatal Microarray Testing, Blood).

Portions of the specimen may be used for other tests such as measuring markers for neural tube defects (eg, AFPA / Alpha-Fetoprotein, Amniotic Fluid), molecular genetic testing, biochemical testing, and chromosome and fluorescence in situ hybridization (FISH) testing (including CHRAF / Chromosome Analysis, Amniotic Fluid; CHRCV / Chromosome Analysis, Chorionic Villus Sampling; and PADF / Prenatal Aneuploidy Detection, FISH).

If additional molecular genetic or biochemical genetic testing is needed, order CULAF / Culture for Genetic Testing, Amniotic Fluid or CULFB / Fibroblast Culture for Biochemical or Molecular Testing, Chorionic Villi/Products of Conception/Tissue so that cultures may be set up specifically for use in these tests.

Shipping Instructions

Advise Express Mail or equivalent if not on courier service.

Necessary Information

1. Provide a reason for testing with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.

2. Notify the laboratory if the pregnancy involves an egg donor or gestational carrier.

Specimen Required

Submit only 1 of the following specimens:

Specimen Type: Chorionic villi

Supplies: CVS Media (RPMI) and Small Dish (T095)

Container/Tube: 15-mL tube containing 15 mL of transport media

Specimen Volume: 20 to 30 mg

Collection Instructions:

1. Collect specimen by the transabdominal or transcervical method.

2. Transfer chorionic villi to a Petri dish containing transport medium (such as CVS Media [RPMI] and Small Dish).

3. Using a stereomicroscope and sterile forceps, assess the quality and quantity of the villi and remove any blood clots and maternal decidua.

Specimen Type: Amniotic fluid

Container/Tube: Amniotic fluid container

Specimen Volume: 20 to 30 mL

Collection Instructions:

1. Optimal timing for specimen collection is during 14 to 18 weeks of gestation, but specimens collected at other weeks of gestation are also accepted. Provide gestational age at the time of amniocentesis.

2. Discard the first 2 mL of amniotic fluid.

Additional Information:

1. Unavoidably, about 1% to 2% of mailed-in specimens are not viable.

2. Bloody specimens are undesirable.

3. Results will be reported and telephoned or faxed if requested.