Prenatal diagnosis of copy number changes (gains or losses) across the entire genome
Diagnosing chromosomal causes for fetal death
Determining recurrence risk of future pregnancy losses
Determining the size, precise breakpoints, gene content, and any unappreciated complexity of abnormalities detected by other methods such as conventional chromosome and FISH studies
Determining if apparently balanced abnormalities identified by previous conventional chromosome studies have cryptic imbalances, since a proportion of such rearrangements that appear balanced at the resolution of a chromosome study are actually unbalanced when analyzed by higher-resolution chromosomal microarray
Assessing regions of homozygosity related to uniparental disomy or identical by descent
A maternal blood sample is requested when ordering this test, see PPAP / Parental Sample Prep for Prenatal Microarray Testing. The PPAP test must be ordered under a different order number than the prenatal specimen.
Maternal cell contamination (MCC) testing will be performed at no additional charge on the maternal blood and fetal tissue to rule out the presence of maternal cells in the product of conception sample.
Testing will not be rejected if maternal blood is not received; however, the possibility of maternal cell contamination cannot be excluded.
A paternal blood sample is desired but not required, see PPAP / Parental Sample Prep for Prenatal Microarray Testing.
If an insufficient sample is received or MCC is identified in the prenatal sample, microarray testing will be performed on cultured material.
If a formalin-fixed, paraffin-embedded specimen is submitted, the test will be cancelled and CMAMT / Chromosomal Microarray, Autopsy/Products of Conception/Stillbirth, Tissue will be added and performed as the appropriate test.
See Frequently Asked Questions: Cytogenetic Testing of Products of Conception by Chromosomal Microarray Analysis in Special Instructions.
