Preimplantation Genetic Testing

PGT-A, PGT-M and NGS Embryo Genetic Screening

Smile IVF Clinic

Preimplantation Genetic Testing, or PGT, is an advanced embryo genetic screening service used in fertility treatment to help identify embryos with suitable chromosomal or genetic characteristics before embryo transfer. This technology supports doctors and embryologists in selecting embryos with a higher potential for successful implantation and healthy pregnancy.

At Smile IVF Clinic, we provide embryo genetic testing using advanced technologies, including Next-Generation Sequencing (NGS), to analyze embryos before they are transferred into the uterus. PGT can be especially beneficial for couples with advanced maternal age, recurrent miscarriage, previous unsuccessful IVF cycles, or a family history of genetic disorders.

What Is Preimplantation Genetic Testing?

Preimplantation Genetic Testing is performed during an IVF or ICSI treatment cycle. After embryos are created in the laboratory, a small number of cells may be carefully collected from the embryo and sent for genetic analysis.

The purpose of PGT is to help detect chromosomal or genetic abnormalities before embryo transfer. This allows the medical team to select embryos that are more likely to result in a successful pregnancy and reduce the risk of miscarriage related to genetic abnormalities.

Why Is Embryo Genetic Testing Important?

Chromosomal abnormalities are one of the major causes of miscarriage, particularly during the first trimester. These abnormalities may occur when an embryo has too many or too few chromosomes, or when there are structural changes in the chromosomes.

By screening embryos before transfer, PGT can help:

Increase the chance of pregnancy success
Reduce the risk of miscarriage caused by chromosomal abnormalities
Support the selection of embryos with normal chromosomal patterns
Help couples with genetic risks plan for a healthier pregnancy
Improve confidence in embryo transfer planning

Understanding Chromosomal Abnormalities

The human body usually has 23 pairs of chromosomes, totaling 46 chromosomes. Chromosomes carry genetic information that determines growth, development, physical characteristics, and biological functions.

Chromosomal abnormalities can generally be divided into two main types:

1. Numerical Abnormalities

These occur when there is an incorrect number of chromosomes, such as an extra or missing chromosome. Examples include:

Down Syndrome, caused by an extra chromosome 21
Patau Syndrome, caused by an extra chromosome 13
Edwards Syndrome, caused by an extra chromosome 18

2. Structural Abnormalities

These occur when the structure of chromosomes changes, such as chromosomal translocation, where parts of chromosomes are rearranged or exchanged. These abnormalities may contribute to infertility, embryo development problems, or recurrent miscarriage.

PGT-A: Preimplantation Genetic Testing for Aneuploidy

PGT-A is a test used to screen embryos for chromosomal abnormalities involving missing or extra chromosomes. It helps identify embryos with the correct number of chromosomes before transfer.

PGT-A may be recommended for patients who want to improve embryo selection, particularly in cases where chromosomal abnormalities are more likely to affect treatment outcomes.

At Smile IVF Clinic, PGT-A can be performed using NGS technology, which allows detailed analysis of all 24 chromosome types, including autosomes and sex chromosomes.

NGS Technology for Embryo Screening

Next-Generation Sequencing (NGS) is an advanced genetic analysis technology used to examine chromosomal information in detail. It provides comprehensive data that helps detect chromosomal abnormalities more accurately.

At Smile IVF Clinic, NGS is used to support embryo chromosome screening with the goals of:

Helping select embryos with appropriate chromosomal patterns
Increasing the chance of successful pregnancy
Reducing the risk of miscarriage related to chromosome abnormalities
Supporting the possibility of a healthy baby

NGS helps provide valuable information for embryo selection and fertility treatment planning.

Who Can Benefit from PGT-A with NGS?

PGT-A with NGS may be suitable for:

Women over 35 years old
Couples with a history of a child born with chromosomal abnormalities
Couples with a history of two or more miscarriages before 12 weeks of pregnancy
Couples with a family history of genetic disorders
Couples who have had two or more unsuccessful IVF cycles
Couples who want additional information to support embryo selection before transfer

The doctor will evaluate each couple’s medical history, fertility condition, and treatment goals before recommending whether PGT-A is appropriate.

PGT-M: Preimplantation Genetic Testing for Monogenic Disorders

PGT-M is a specialized genetic test used to screen embryos for specific single-gene disorders before implantation. It is designed for couples who are known carriers of certain inherited genetic conditions or have a family history of genetic disease.

Single-gene disorders may include conditions such as:

Thalassemia
Duchenne Muscular Dystrophy
Cystic Fibrosis
Certain inherited respiratory diseases
Other specific genetic conditions identified in the family

PGT-M helps identify embryos that are not affected by the specific genetic condition being tested, reducing the chance of passing that condition to future children.

Genetic Disorders and Family Planning

Genes are units of heredity made from DNA. Changes or mutations in genes can sometimes cause inherited disorders. These conditions may be passed from parents to children, even when the parents themselves do not show symptoms.

Genetic disorders can be divided into:

Single-Gene Disorders

These are caused by changes in one specific gene and may be inherited through dominant or recessive patterns.

Multifactorial Disorders

These conditions may involve multiple genes together with environmental or lifestyle factors, such as heart disease, diabetes, obesity, Alzheimer’s disease, and some cancers.

For couples with known genetic risks, genetic counseling and embryo testing can help support informed decision-making before pregnancy.

PGT at Smile IVF Clinic

At Smile IVF Clinic, Preimplantation Genetic Testing is provided as part of advanced fertility care for couples undergoing IVF or ICSI treatment. Our team of fertility specialists, embryologists, and laboratory professionals works together to provide careful embryo assessment, genetic screening coordination, and personalized treatment planning.

Through advanced technologies such as NGS, PGT-A, and PGT-M, Smile IVF Clinic aims to help couples improve their chances of pregnancy, reduce genetic risks where appropriate, and move toward parenthood with greater confidence.