What tests are needed to further define the Chromosomal Abnormalities in baby?

The most common test is a chromosome analysis, or karyotype. This is done using a blood sample. About a teaspoon of blood is collected and sent to a cytogenetics lab (the kind of lab that looks at chromosomes). The lab will process the sample, take pictures of the chromosomes, count them, and look at them closely. The lab is looking for large changes in the chromosomes, such as a missing or extra piece. This type of test does not see small changes in the genetic material. The chromosome analysis takes ten days to two weeks.

Fluorescence in situ hybridization (FISH) is a way of looking at smaller pieces of genetic material. Depending upon your baby’s specific features, a FISH test may be ordered. A newer type of test is the Chromosome Microarray Analysis (CMA), which can also test for changes in smaller pieces of genetic material. It may be ordered rather than a FISH test.