What is a Preimplantation Genetic Diagnosis?
A chromosome and/or genetic study of the embryos is performed before they are transferred to the mother’s uterus. In this way, the “healthy” embryos with respect to the anomalies being studied can be selected.
The most frequently studied chromosome disorders are, for example: Down’s Syndrome, Edward’s Syndrome, sex chromosome disorders, such as Turner’s Syndrome, and monogenic disorders, such as cystic fibrosis, Duchenne muscular dystrophy, etc. It can also include sexing to prevent genetic disorders linked to a particular sex.
It is recommended for couples who are carriers or sufferers of a genetic or chromosome disorder, and hence are at risk of transferring the disorder to their children. In some cases, it is also recommended for recurrent miscarriage sufferers or older women, given the increased risk of chromosome disorders in the foetus. Throughout this process, clinical specialists and embryologists are required, as well as specialised geneticists, who study each case individually.
First appointment: In this first consultation, the problem is discussed and after a medical assessment, the necessary tests for both members of the couple are requested. These tests are essential to determine the cause of the infertility and to identify the most appropriate technique for each couple.
What is entailed by a PGD?
The first step is an ovarian stimulation and controlled ovulation induction through medication. The objective is to stimulate ovulation to obtain an appropriate number of oocytes for the laboratory work, increasing the possibility of success. All the treatments are personalised and the patient is monitored during the days when she is administered the medication.
The second step is to extract the oocytes vaginally by means of an ovarian puncture, with the patient sedated. The oocytes are then fertilised in the lab with the male sperm. Between 16 and 18 hours later, the oocytes are checked to see if they have been fertilised and the couple is informed of the results.
PREIMPLANTATION GENETIC DIAGNOSIS – EMBRYO VITRIFICATION
The embryos selected are subjected to a biopsy by means of a small orifice through which a small number of cells are extracted. Following this procedure, the embryos are vitrified (cryopreservation) while waiting for the genetic analysis results. 10 days later, the genetic analysis results are available, indicating which embryos are healthy with regards to the disorders studied.
TRANSFER OF THE BEST EMBRYO
After 10 days, the results are obtained and the healthy embryos according to the chromosome analysis are selected. After the patient’s endometrial preparation, a healthy embryo is defrozen for transfer to the mother’s uterus. This process is performed in the surgery due to its closeness to the lab and for aseptic reasons, but it is a pain-free process that does not require sedation.
We will let you know the best date to have a blood pregnancy test, which tends to be 8 days after the transfer. You will be able to lead a normal life during that time, although high-intensity activities are not recommended.
We select specific embryos depending on the anomalies studied.
Our success rates
This technique offers higher success rates than ordinary in vitro fertilisation because of the chromosome analysis performed prior to the transfer.
* Statistics for our patients in 2021.
Request an appointment and we will inform you of what is the most appropriate treatment for you. We are specialists in providing personalised care for our patients.
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Request an appointment and we will inform you of what is the most appropriate treatment for you We specialize in personalized attention to our patients.