PGD/PGS/PGT-A: A Boon for Couples with Genetic Concerns
What is Pre-Implantation Genetic Testing (PGT)?
Many couples undergoing IVF face genetic challenges. Pre-Implantation Genetic Testing (PGT) offers a proactive solution to identify genetic issues in embryos before implantation, helping ensure a healthier pregnancy and baby.
PGT includes three key types:
- PGD (Preimplantation Genetic Diagnosis) – Detects specific inherited diseases.
- PGS (Preimplantation Genetic Screening) – Screens for chromosomal abnormalities.
- PGT-A (Preimplantation Genetic Testing for Aneuploidy) – A modern form of PGS with enhanced accuracy.
Though sometimes used interchangeably, each serves a unique purpose and is recommended based on individual medical history.
Why Consider PGD/PGS/PGT-A?
Preimplantation Genetic Testing is performed during an IVF cycle to:
- Identify embryos with chromosomal or genetic abnormalities.
- Increase the chances of a healthy pregnancy and live birth.
- Prevent the transmission of inherited disorders, especially for couples with a known family history.
PGD is ideal for:
Couples at risk of passing on serious single-gene disorders (like cystic fibrosis, thalassemia, Huntington’s disease).
PGS/PGT-A is useful for:
- Women of advanced maternal age.
- Cases of recurrent miscarriage.
- Severe male factor infertility.
- Couples experiencing repeated IVF failure.
Note: PGT is not used for sex selection and should only be considered after a thorough medical consultation.
Uses of PGD/PGS/PGT-A
PGT helps identify and select genetically normal embryos before transfer, which can:
- Improve implantation success.
- Reduce the risk of miscarriage.
- Prevent hereditary diseases.
- Aid in family planning for couples with a history of genetic abnormalities.
PGT is especially beneficial when:
- A couple has experienced repeated IVF failure.
- There is a history of early miscarriage.
- Either partner carries a known genetic mutation.
- There is a need to create a savior sibling to treat an existing child with a genetic condition.
PGT-A vs PGT-M: What’s the Difference?
- PGT-A checks for aneuploidy – abnormal number of chromosomes.
- PGT-M (Monogenic) detects specific gene mutations associated with hereditary diseases.
Examples:
- PGT-A helps avoid chromosomal disorders like Down syndrome (extra chromosome 21) or Turner syndrome (missing X chromosome).
- PGT-M helps prevent single-gene disorders like sickle cell anemia or Tay-Sachs disease.
Preimplantation Genetic Testing Process
- Consultation: Your fertility expert evaluates your medical history and discusses testing options.
- Ovarian Stimulation: Hormonal medications are given to stimulate egg production.
- Egg Retrieval & Fertilization: Eggs are collected and fertilized in the lab.
- Embryo Culture: Embryos are grown to the blastocyst stage (usually Day 5 or 6).
- Embryo Biopsy: A few cells are extracted from each embryo without harming it.
- Genetic Testing: The biopsied cells are screened for abnormalities.
- Embryo Transfer: Only healthy embryos are selected and transferred to the uterus.
Benefits of PGT-A
- Improves Pregnancy Success
- Reduces Risk of Miscarriage
- Helps Avoid Multiple Pregnancy
- Minimizes Risk of Genetic Disorders
- Saves Time & Costs in IVF Cycles
Fast Facts
To minimize the risk of genetic disorders
To screen for single-gene inherited conditions
