In vitro fertilization (IVF) treatment is not exclusively applied to couples unable to conceive naturally. It can also be employed for individuals who can conceive naturally but have certain genetic diseases or are carriers. This significantly reduces the likelihood of genetic diseases in the offspring.
What is Preimplantation Genetic Diagnosis (PGD)?
This method involves assessing whether the chromosomal structures of embryos obtained during in vitro fertilization (IVF) are healthy. The health of their chromosomal structures is referred to as aneuploidy in medical terminology. Aneuploidy can occur in embryos, similar to its occurrence in sperm or eggs. This issue may lead to intellectual disabilities or physical problems in the offspring. Preimplantation genetic diagnosis (PGD) aims to ensure the health of unborn babies.
Chromosomal disorders are not only evident in the embryo. There may also be problematic sperm or egg cells. Babies with genetic disorders can be born as a result of the fertilization of these cells. In PGD, the health status of both sperm and egg cells is also examined.
How is Preimplantation Genetic Diagnosis (PGD) Performed?
The PGD method, performed without causing harm to the embryo, can be conducted in three different ways.
- A biopsy called polar body biopsy is conducted on the ovaries of the prospective mother to identify diseases specific to the mother.
- One of the most commonly preferred methods involves sampling tissue from the embryo. A biopsy is performed on a 3-day-old embryo, with the condition that it must be 6-8 cells.
- The method called blastocyst biopsy takes a tissue sample from a 5-day-old embryo. It can reveal all 46 chromosomes numerically.
Who Should Undergo Preimplantation Genetic Diagnosis (PGD)?
- Preimplantation Genetic Diagnosis (PGD) is performed when screening tests indicate the presence of a single-gene disorder in at least one of the partners. The probability of the disease being passed on to the baby is then discussed.
- This is done to prevent newborn babies from developing a single-gene disease if a single-gene disease is detected in the children born to a couple. These diseases can be cystic fibrosis, thalassemia, sickle cell anemia or hemophilia.
What Are the Advantages of Preimplantation Genetic Diagnosis (PGD)?
PGD is very important for the health of future babies. This brings the following advantages.
- It ensures that the healthiest embryo is selected for transfer to the mother's uterus. This significantly increases the success rate of pregnancy.
- It is an important factor in reducing the risk of miscarriage during pregnancy. In some cases, having genetic diseases reduces the success rate of pregnancy.
- It is effective in deciding which embryos to freeze or eliminate in IVF treatment.
Additionally, research is being conducted on PGD for the diagnosis of cardiovascular diseases, diabetes, hypertension, and especially cancers. The aim is to prevent these diseases in future generations.
In Which Situations Does Preimplantation Genetic Diagnosis (PGD) Method Provide Success?
- It increases the possibility of pregnancy in older individuals. Especially in pregnancies of women over the age of 35, some anomalies may be observed in the child to be born. It contributes to their prevention.
- In recurrent pregnancy losses and recurrent IVF failures, if the problem is genetic factors, it increases the chance of pregnancy.
- It ensures that the newborn baby is healthy if either of the couple has been diagnosed with genetic diseases or if the child already born has genetic diseases.
What are the Disadvantages of Preimplantation Genetic Diagnosis (PGD)?
The biopsy method is used in the diagnosis of genetic diseases. This situation can lead to some technical errors. Even if the procedure is successful, achieving success during the transfer of the embryo to the mother's uterus may not be guaranteed. Additionally, the biopsy performed allows for only a limited number of tests. Unfortunately, testing for every type of genetic disease may not be possible. As a result, there is a possibility of other genetic disorders in the baby, apart from the researched disease.
