A karyotype is a test to examine the number and structure of chromosomes in a sample of cells. Each cell must have a total of 46 chromosomes divided into 22 autosome matching pairs and two sex chromosomes. The latter determine the sex of the baby. The karyotyping is done as a blood test.

Carriers of defective chromosomes often have fertility problems due to a low production or abnormal structural changes of the gametes.

Karyotype tests are strongly recommended in couples with fertility problems, especially if they have had recurrent miscarriages or several implantation failures.

Cromosomes