Preimplantation Genetic Diagnosis (PGD)
PGD (preimplantation genetic diagnosis) is an application that scans the genetic structures of the embryos that have not yet been transferred. This application helps diagnose any genetic anomalies in the embryos before the pregnancy takes place. This enables the prevention of reoccurring unsuccessful treatments, pregnancies where the embryo has a genetic disorder or the child being sick from birth and the resulting difficulties this child may face in the future.
It is important for preimplantation genetic diagnosis to be conducted in developed laboratories by experienced doctors and embryologists. The Near East IVF Clinic embryology laboratory has technological equipment that is not available in any other centre in Cyprus.
In which situations is PGD applied?
Depending on their infertility diagnosis and the patient’s situation, couples can be candidates for PGD in the following situations:
- If the patient has previously had more than two unsuccessful IVF treatments regardless of good embryo quality,
- If they have a previous history of more than two early pregnancies,
- If the prospective mother is over 37 years of age,
- If one of the spouses has a genetic chromosome anomaly,
- If there is a previous history of an abnormal chromosome pregnancy.
PGD Used for Rare Genetic Diseases
Evaluation of present genetic disease carriers within the family:
For us to be able to determine the genetic pathology of the embryos and to apply this technology, we must first conduct a detailed genetic scan of the couples. Hundreds of genetic diseases with known mutations can be analysed in the embryo with routine procedures. However, there are also many types of genetic diseases that cannot be analysed correctly with modern technology which also do not show in classic Mendel genetics. Due to this reason, the genetic condition in questions must be evaluated and discussed by the couples and their specialists.
Preparation for analysis at a single cell level:
If the genetic situation or disease is not clinically diagnosed, then the mutation gene deformity that causes the disease can be tested on the whole family using molecular genetic techniques and the data obtained must be recorded. Then, according to these results, the genetic model and form of the mutations can be analysed and determined with definite accuracy. Due to the diagnosis being made on a single cell level, many other genetic regions are also examined and included in the preparation period in order to reduce the rate of mistakes to a minimum. This preparation period can take a few days or a few weeks due to the genetic complication and is the most important and longest procedure in the treatment package.
Ovulation induction and IVF treatment:
After the preparation stage is completed, the genetic laboratory informs the IVF clinic that they can begin routine treatment. The doctor then calls the perspective mother for a detailed clinical evaluation and if the mother is deemed to be suitable, then the doctor begins the ovulation induction protocol to produce many egg cells. The collection of the egg cells, insemination and embryo development procedure are the same as in the conventional IVF treatment.
In order to determine the genetic structure of the embryos, a cell sample is taken from an embryo biopsy in order to evaluate whether the embryo development is continuing as expected. The main aim of the embryo biopsy is to take one or more cells without damaging the embryo’s growth and development under normal conditions. As this is an interventional procedure, it must be stated that it does carry a risk of harm. However, when conducted by experienced personnel, this risk is significantly lower than the similar risks in the amniocentesis procedure.
Determine the genetic disease in the biopsy cells:
According to the preparation protocol, the materials obtained after the biopsy are examined for the genetic disease in question and it is determined whether or not the embryos are suitable for transfer. Embryos that are found to be suitable based on the embryo development results and genetic analysis results are then prepared for embryo transfer. In some cases, the embryo transfer step may be delayed due to specific medical or social reasons. In such cases, the embryos deemed to be suitable for pregnancy are frozen and can be kept (for months or years) until the embryo transfer.
Embryo transfer with genetically normal/suitable embryos:
Embryos that have been determined to be genetically ‘’healthy’’ are transferred into the womb with the fresh or frozen embryo transfer method. The PGD procedure is a method that we have conducted for many years in the case of rare genetic disease carriers. It can be applied for all genetic diseases with a genetic mutation/deformity that is known to cause disease.