What are the tests done on the amniotic fluid
What are the tests done on the amniotic fluid
The following tests can be done on the amniotic fluid:
- Chromosome Analysis
- Examination of Aphafetoprotein
- Other tests if indicated
The laboratory tests
Karyotype
Using special procedures in the laboratory, cells are grown in a culture medium. The cells are then fixed and stained. With high power microscopy the chromosomes in these cells can be examined and in this way it possible to find out if the baby has Down syndrome, or any of the other known less common chromosome problems. This is called a karyotype. Also, by looking at the chromosomes, the sex of the baby can be determined.
Fast FISH
In order to get faster results, the laboratories have developed a technique called fast Fluorescent In-Situ Hybridization, where some of the cells from the sample are stained with a fluorescent dye. This can give us results for chromosomes 13, 18, 21, X & Y, in 24 hours. This is especially popular for women who have had a high risk result for Down syndrome (Trisomy 21)
Amniotic fluid AFP
The amount of a particular protein alpha fetoprotein can also be measured. There is usually an increased amount of this protein present in the fluid when the baby has the abnormality called spina bifida. However these days, modern ultrasound equipment is better at detecting spina bifida than the amniotic fluid alpha fetoprotein test. So these days amniotic fluid AFP is only ordered under special circumstances.