FISH (Fluorescence in situ Hybridization) is a cytogenetic technique that allows study of the genetic material in a cell. By applying FISH technique in sperm cells, we can determine if there is any increasing risk of chromosome malsegregation in sperm.
Any somatic (non-reproductive) cell in the human body has 23 pairs of chromosomes, in other words, 2 copies of each chromosome. However, human gametes (sperm cells and oocytes), to be chromosomally normal, must have 23 chromosomes, i.e. a single copy of each chromosome.
What is necessary for this test?
The only thing needed is a sperm sample taken in a sterile container.
When is performed a Sperm FISH?
It is advisable to request this technique in the following cases:
Patients with any type of seminal alteration: a low sperm count (oligozoospermia), low mobility (astenozoospermia), or altered morphology (teratozoospermia).
Patients with recurrent miscarriage: when a couple has two or more spontaneous miscarriages, it may be a symptom of a genetic alteration.
Patients with failed IVF (In Vitro Fertilisation) attempts: when a couple has carried out two or more IVF cycles without achieving pregnancy, it may be due to an embryonic chromosomal problem.
What information is obtained by Sperm FISH?
An altered FISH study is a diagnosis of chromosomal anomalies in sperm cells.
If the result of the study indicates that there is a high proportion of chromosomally altered sperm cells, it means that when these sperm cells fertilize the eggs they may produce chromosomally altered embryos.
In these cases it is necessary to study these embryos to be able to identify those that are chromosomally normal. This is carried out by an In Vitro Fertilisation cycle with Preimplantation Genetic Diagnosis.