Preimplantation Genetic Diagnosis detects the presence of the most common genetic and chromosomal alterations in embryos, allowing the baby to be born healthy and free of serious hereditary diseases.
The origin of hereditary diseases is in DNA abnormalities that parents transmit to their offspring, whether they are genetic or chromosomal alterations. The DGP analysis allows detecting them in embryos developed from an assisted reproduction treatment to select only healthy ones.
PGT-A (Preimplantation Genetic Testing for aneuploidy): Allows to detect anomalies in the number of chromosomes (aneuploidies). Normally, a person has 23 pairs of chromosomes, 46 in total. However, sometimes one of these chromosomes has three copies (trisomy) or only one (monosomy), resulting in genetic alterations. Some examples of trisomy are Down syndrome (chromosome 21) or Klinefelter syndrome (an extra X chromosome), which affects only males. On the other hand, among the monosomal alterations we have Turner syndrome, in which a woman has a single X chromosome.
PGT-M (Preimplantation Genetic Testing for monogenics): Monogenic diseases that develop due to the alteration in the genetic information of a particular gene. Thalassemia, haemophilia or cystic fibrosis are included in this group.
WHO IS IT FOR?
- Advanced maternal age (from 38 years old increases the risk of the embryo developing chromosomal diseases)
- Repeated miscarriages
- Men with sperm DNA alterations
- Carrier couples or suffering from hereditary diseases
- Family history of genetic diseases.
- Healthy embryos
- Altered embryos
- Healthy embryos
- Altered embryos
Age has a negative impact on egg quality, so the older it is, the greater the percentage of embryos with chromosomal alterations. Therefore, in this group of patients it will be more advantageous to do DGP to exclude altered embryos and increase the chances of pregnancy with a transfer of a healthy embryo.
- Can the PGD guarantee the birth of a completely healthy child?
Nowadays there is no technique that guarantees 100% the health of a child. With the PGD that is performed more commonly (PGT-A), we can study the alterations in chromosomes (syndromes such as Down, Edwards or Patau), but malformations cannot be ruled out, nor genetic diseases such as cystic fibrosis, muscle dystrophy, thalassemias …
If the patient is a carrier of one of these genetic diseases, with a PGT-M test this particular disease can be studied in the embryo, but not all the genetic diseases that exist.
- Can the embryo be damaged by performing a biopsy for the PGD?
The possibility of an embryo degenerating as a result of the biopsy is minimal. The technique is very protocolized and in FIV Marbella we have professionals with the necessary experience.
In addition, the biopsy of the embryo in the blastocyst stage has proven to be a safe technique that does not harm the future baby.
- Can I have healthy children if I have a genetic disease?
Depending on the type of inheritance of the disease there will be a 25% or 50% chance of having an affected child. The way to avoid it would be with the PGD.
In the first place, a genetic study will have to be carried out to identify the alteration and the gene responsible for the disease. Subsequently, a study of informativity is required. This study helps us to obtain the necessary information to be able to study this alteration in the embryo, and sometimes it requires the participation of the relatives of the patients. The informativity study, once carried out, is used for all the necessary treatment cycles.
he success rates shown correspond to those of our headquarters in Marbella. The percentages presented in this section have been divided as follows:
eta-hCG positive: hormone produced by the body once the embryo is implanted in the uterus. Calculated after 10/12 days after embryo transfer.
Clinical Pregnancy: Calculated in the 4 week gestation by means of ultrasound. Its presence is a sign of implantation of the embryo in the endometrium.
SEF (Spanish Fertility Society). The rates shown here correspond to the last report published by the agency in 2016.