GENETIC TESTING IS RECOMMENDED FOR:
- Long-standing idiopathic infertility.
- Infertility with a severe semen disorder.
- Poor oocyte quality after IVF treatment.
- Poor embryo quality.
- Recurrent miscarriages.
- History of genetic disorders in the family.
- Previous baby with a genetic syndrome.
- Desire to know if a member of the couple is a carrier of recessive diseases (recessive panel).
The purpose of these studies is to know if anyone is a carrier of any genetic condition that increases the risk of inheritance of that condition in the offspring resulting in an affected fetus or miscarriage.
EMBRYONIC GENETIC STUDIES
PGT-A: Definitions and usefulness
For a pregnancy to occur, there must be a euploid embryo (with the normal number of chromosomes), which implants in a receptive endometrium.
Not all embryos are genetically normal, and this is the main limitation for the achievement of pregnancy.
Selection of the best embryo for embryo-transfer is performed at the embryology lab on the basis of embryonic
morphological aspect, but this does not mean that the embryo is genetically normal. In turn, embryos that do
not have an optimal appearance can implant, so genetic normality is the main determinant of the outcome.
PGT-A, or preimplantation genetic test for aneuploidy, is a study performed on the embryo to study its number
of cromosomes chromosomes.
The embryo is allowed to evolve until day 5 or 6 to form a blastocyst (80 to 130 cells), when 5 cells are mechanically extracted under the microscope from the cellular region that will give rise to the placenta. The cells obtained are sent for a DNA testing, allowing selection of embryo/s with a normal number of chromosomes to be transferred.
PGT-A is especially useful in women over 35 years old, in patients with unexplained recurrent miscarriages, or in those with repeated embryo implantation failure.
Transferring an euploid fetus does not guarantee achieving pregnancy. A receptive endometrium and normal implantation are also needed. therefore, worldwide reported pregnancy rate is 60 to 70% per euploid embryo.
PGT-M or PGT-SR:
When a person has a genetic disease or is a carrier of a mutation (with no clinical manifestation), a proportion of the offspring will inherit the genetic condition. In these cases, an ICSI cycle followed by embryo biopsy can be performed in order to select normal embryos for transfer and freezing.
EMBRYONIC GENETIC STUDIES
PGT-A: Definitions and usefulness
For a pregnancy to occur, there must be a euploid embryo (with the normal number of chromosomes), which implants in a receptive endometrium.
Not all embryos are genetically normal, and this is the main limitation for the achievement of pregnancy. Selection of the best embryo for embryo-transfer is performed at the embryology lab on the basis of embryonic morphological aspect, but this does not mean that the embryo is genetically normal. In turn, embryos that do not have an optimal appearance can implant, so genetic normality is the main determinant of the outcome.
PGT-A, or preimplantation genetic test for aneuploidy, is a study performed on the embryo to study its number of cromosomes chromosomes.
The embryo is allowed to evolve until day 5 or 6 to form a blastocyst (80 to 130 cells), when 5 cells are mechanically extracted under the microscope from the cellular region that will give rise to the placenta. The cells obtained are sent for a DNA testing, allowing selection of embryo/s with a normal number of chromosomes to be transferred.
Transferring an euploid fetus does not guarantee achieving pregnancy. A receptive endometrium and normal implantation are also needed. therefore, worldwide reported pregnancy rate is 60 to 70% per euploid embryo.
PGT-A is especially useful in women over 35 years old, in patients with unexplained recurrent miscarriages, or in those with repeated embryo implantation failure.
PGT-M or PGT-SR:
When a person has a genetic disease or is a carrier of a mutation (with no clinical manifestation), a proportion of the offspring will inherit the genetic condition. In these cases, an ICSI cycle followed by embryo biopsy can be performed in order to select normal embryos for transfer and freezing.