Preimplantation Genetic Diagnosis (PGT)
Preimplantation Genetic Diagnosis (PGT) is a medical procedure used to examine the genetic structure of embryos and detect specific genetic diseases or chromosomal abnormalities. This technique enables genetic analysis of embryos in a laboratory setting before implantation during in vitro fertilization (IVF) treatment. PGT allows for the identification of embryos carrying various genetic disorders and the selection of healthy embryos, thereby facilitating the transfer of high-quality embryos and achieving a healthy pregnancy.
The popularity of Preimplantation Genetic Diagnosis (PGT) is based on its potential to reduce the risk of genetic diseases and facilitate the birth of healthy babies. It is a significant source of hope, especially for couples who are at high genetic risk. PGT may also help prevent recurrent miscarriages and repeated IVF failures.
This technique helps detect various genetic diseases and chromosomal abnormalities. In addition to common chromosomal abnormalities such as Down syndrome, it also enables the identification of single-gene disorders. In this way, the transfer of affected embryos can be prevented, and the most suitable embryo can be selected to achieve a healthy pregnancy. This is of great importance for both maternal health and the healthy birth of the baby.
However, PGT also has certain limitations and ethical considerations. For example, only specific genetic diseases can be detected with this technique, and it cannot guarantee the complete elimination of all genetic errors. Additionally, PGT is generally costly and may not be accessible to all couples. Therefore, the widespread adoption and availability of PGT depend on both technological and social factors.
What Is PGT (Preimplantation Genetic Diagnosis)?
Preimplantation Genetic Diagnosis (PGT) is a medical procedure used to perform genetic analysis of embryos during IVF treatment. This process aims to identify specific genetic diseases, chromosomal abnormalities, or genetic carrier statuses by examining the genetic structure of embryos. PGT allows genetic analysis of embryos in a laboratory environment prior to implantation, enabling the selection of the most suitable embryo for transfer to achieve a healthy pregnancy.
PGT is generally recommended for couples who are at high genetic risk or individuals with a family history of specific genetic diseases. This procedure can help reduce the risk of genetic disorders and increase the chances of having a healthy baby. It may also offer a solution for couples experiencing recurrent miscarriages or repeated IVF failures.
The benefits of PGT include:
Detection of genetic diseases and chromosomal abnormalities: In addition to common chromosomal abnormalities such as Down syndrome, single-gene disorders can also be identified.
Selection of healthy embryos: PGT helps prevent the transfer of affected embryos and allows the selection of the most suitable embryo for achieving a healthy pregnancy.
Prevention of recurrent pregnancy loss: PGT can help identify the causes of recurrent miscarriages and reduce pregnancy losses through the transfer of healthy embryos.
Detection of genetic carrier status: PGT can determine carrier status for certain genetic diseases and provide couples with information about their genetic risks.
The PGT procedure involves genetic analysis of embryos in a laboratory setting during IVF treatment before implantation. This process is performed through a biopsy during the cell division stages following fertilization. The biopsy is usually conducted when embryos are 5 to 7 days old, and results are typically obtained within a few days. This process enables couples to select and transfer the most suitable embryo for a healthy pregnancy.
What Are the Methods of PGT (Preimplantation Genetic Diagnosis)?
Preimplantation Genetic Diagnosis (PGT) includes different methods used for genetic analysis. These methods use various techniques to examine the genetic structure of embryos and detect specific genetic diseases or chromosomal abnormalities. Below are the PGT methods and detailed explanations of how each works:
1. PGT-M (PGT for Monogenic Disorders)
PGT-M is a PGT method used to detect and prevent monogenic (single-gene) disorders. These genetic disorders result from a mutation in a single gene and may lead to specific diseases. The PGT-M method involves analyzing specific genes in the embryo’s genetic material and allows the identification of any mutations in those genes. This method is generally intended for couples with a family history of a particular monogenic disease or individuals known to be genetic carriers.
The PGT-M process typically includes the following steps:
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Retrieval of cellular material from the embryo (biopsy)
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Amplification of the embryo’s DNA
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Analysis of specific genes using PCR or other molecular techniques
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Detection of genetic mutations and identification of healthy or affected embryos
2. PGT-SR (PGT for Structural Chromosomal Rearrangements)
PGT-SR is a PGT method used to detect and prevent structural chromosomal rearrangements (such as translocations, inversions, deletions, etc.). These types of chromosomal abnormalities result from structural changes in chromosomes and may cause fertility problems or recurrent pregnancy loss. The PGT-SR method enables detailed examination of the chromosomal structure of embryos, allowing the selection of embryos with a healthy chromosomal composition.
The PGT-SR process typically includes the following steps:
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Retrieval of cellular material from the embryo (biopsy)
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Amplification of the embryo’s DNA
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Use of techniques such as microdissection or FISH for chromosomal structure analysis
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Detection of structural chromosomal abnormalities and identification of healthy or abnormal embryos
3. PGT-A (PGT for Aneuploidy)
PGT-A is a PGT method used to determine the presence of aneuploidy (abnormal number of chromosomes) in embryos. Aneuploidy refers to a deviation from the normal number of chromosomes and may occur due to factors such as advanced maternal age, IVF treatment, or genetic predisposition. The PGT-A method analyzes the chromosomal structure of embryos and allows the selection of embryos with a normal chromosomal composition.
The PGT-A process typically includes the following steps:
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Retrieval of cellular material from the embryo (biopsy)
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Amplification of the embryo’s DNA
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Use of techniques such as microdissection or NGS to analyze chromosome number
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Detection of aneuploidies and identification of embryos with normal or abnormal chromosomal structures
What Are the Complications of the Preimplantation Genetic Diagnosis Procedure?
Preimplantation Genetic Diagnosis (PGT) is generally used to increase the chances of achieving a healthy pregnancy. However, as with any medical procedure, PGT carries some potential risks. These include:
Embryo loss: During the biopsy procedure, removing cellular material from the embryo may sometimes cause damage or loss of the embryo.
False positive or false negative results: Laboratory errors or challenges in obtaining representative cells during embryo biopsy may result in false positive or false negative outcomes. This may lead to the rejection of healthy embryos or the unintentional selection of affected embryos.
Pregnancy complications: Some evidence suggests that the use of PGT may be associated with pregnancy complications. For example, trauma caused during embryo biopsy may affect the implantation process and lead to implantation failure or miscarriage.
Ethical and psychosocial challenges: Ethical and psychosocial issues may arise in relation to PGT. Decisions regarding the selection or rejection of embryos identified as high-risk or affected may cause stress, anxiety, and emotional difficulties for couples.
High cost: The PGT procedure is generally expensive and may not be accessible to all couples. This can limit its use and restrict access to this advantageous medical treatment.
Rare health risks: The instruments or methods used during biopsy carry a small risk of rare complications, such as infections, bleeding, or intrauterine damage.
These risks are generally low and should be evaluated in light of the potential benefits provided by PGT. However, as with any medical procedure, it is important to consider the potential risks associated with its use.
How Can the Risk of These Anomalies Be Reduced?
Some measures that can be taken to reduce potential risks during the PGT procedure include:
Selecting an experienced and specialized healthcare team: The PGT procedure should be managed by an experienced medical team with the necessary training and expertise to perform the procedure correctly and minimize possible complications.
Using precise and reliable technologies: The technologies used for PGT should be accurate and reliable. Laboratory equipment and analytical methods should incorporate the latest technology and proven techniques to ensure accurate results.
Careful embryo biopsy: During embryo biopsy, careful techniques and appropriate equipment should be used to avoid damaging the embryo and to ensure proper development.
Ethical counseling and psychological support: Couples should receive ethical counseling and psychological support before and after the PGT procedure. This can help support decision-making and coping with potential challenges.
Detailed explanation of risks: Healthcare professionals should thoroughly explain the potential risks and complications that may arise during the PGT procedure. Access to and understanding of this information help couples make informed decisions.
Monitoring the recovery process: After the PGT procedure, during embryo transfer and pregnancy follow-up, the healthcare team should closely monitor the patient’s recovery process. This enables early detection of possible complications and timely intervention.
These measures may help reduce potential risks during the PGT procedure. However, each patient’s situation is unique, and specific precautions should be determined through individualized medical evaluation.
What Is the 2026 Price of Preimplantation Genetic Diagnosis?
In Turkey, the cost of Preimplantation Genetic Diagnosis (PGT) in 2024 generally varies depending on the couple’s preferences, medical needs, and the technology used. Since such medical procedures are typically costly, PGT prices may be relatively high, similar to other countries.
Many IVF centers and private clinics in Turkey offer Preimplantation Genetic Diagnosis services, and prices may vary from one center to another. On average, the cost of PGT may range from several thousand Turkish Lira to tens of thousands of Turkish Lira.
On the other hand, leading IVF centers such as NovaArt may offer high-quality services, which can be associated with higher costs. In such centers, the price of PGT may be slightly higher compared to other clinics due to the advanced technology and specialized expertise required. However, these prices are not definitive, and each patient’s situation is different. Couples are advised to contact an IVF center directly to obtain accurate and up-to-date pricing information for the Preimplantation Genetic Diagnosis procedure. It may also be beneficial to check whether such services are covered by health insurance.
The Role of NGS (Next Generation Sequencing) in PGT
Preimplantation Genetic Testing (PGT) plays a critical role in detecting genetic abnormalities in embryos. Next Generation Sequencing (NGS) technology has revolutionized this process. Following DNA amplification, NGS fragments DNA into millions of small pieces and reads their sequences. Compared to aCGH, this method is more sensitive and accurate and can detect mosaicism in embryos at rates as low as 20%.
The high sensitivity and accuracy of NGS increase the success of PGT, enable the selection of healthy embryos, and improve the success rates of IVF treatments. As a result, PGT integrated with NGS offers a significant advantage for achieving healthy pregnancies and births while reducing the risk of transmitting genetic diseases across generations.
What Is the Difference Between Prenatal and Preimplantation Genetic Diagnosis?
The main differences between Prenatal and Preimplantation Genetic Diagnosis are summarized in the table above. Both methods provide genetic analysis; however, they differ significantly in timing and biopsy location.
Prenatal Genetic Diagnosis is generally performed during pregnancy and allows examination of the fetus’s genetic structure. This method is typically used to detect specific genetic diseases or chromosomal abnormalities during pregnancy. Once a diagnosis is made, treatment options during pregnancy can be evaluated, or decisions such as pregnancy termination may be considered.
Preimplantation Genetic Diagnosis, on the other hand, involves genetic analysis of embryos before implantation. This method is used during IVF treatment and allows examination of the embryo’s genetic structure prior to pregnancy. It helps in selecting healthy embryos and increases the chances of achieving a healthy pregnancy.
Prenatal Genetic Diagnosis is generally recommended for couples at risk of specific genetic diseases during pregnancy or for patients in whom chromosomal abnormalities are detected during gestation. Preimplantation Genetic Diagnosis is typically recommended for couples undergoing IVF treatment or those carrying a known risk of genetic disorders. This method is used to increase the likelihood of a healthy pregnancy and to prevent the transmission of genetic diseases.
