Preimplantation Genetic Testing (PGT)
Preimplantation Genetic Testing (PGT)
Preimplantation Genetic Testing (PGT) is an essential advanced screening procedure used during IVF to identify genetic or chromosomal abnormalities in embryos before they are transferred to the uterus. By selecting only chromosomally healthy embryos, clinicians can significantly improve implantation rates, reduce the risk of miscarriage, and prevent the transmission of specific genetic disorders. Modern PGT utilizes high-precision genomic sequencing to offer intended parents the highest level of diagnostic accuracy currently available.
When You Should Consider PGT
Advanced maternal age (typically over 35), where the risk of chromosomal aneuploidy increases.
History of recurrent pregnancy loss or multiple unsuccessful IVF cycles.
Known carriers of single-gene disorders such as Cystic Fibrosis, Thalassemia, or Sickle Cell Anemia.
Parents with known chromosomal structural rearrangements, such as translocations or inversions.
Desire to maximize the success of a Single Embryo Transfer (SET) to avoid multiple pregnancies.
Previous pregnancy affected by a chromosomal abnormality or a specific genetic condition.
Conditions That Require Specialized Care
Recurrent Miscarriage linked to chromosomal imbalances in the embryo.
High-risk genetic profiles where both partners are carriers for the same recessive condition.
Cases of severe male factor infertility, which can be associated with higher rates of embryo aneuploidy.
Patients opting for "freeze-all" cycles who want to ensure only viable embryos are stored.
Families seeking to eliminate the risk of late-onset genetic conditions through PGT-M.
How Preimplantation Genetic Testing Is Performed
Embryos are cultured in a specialized laboratory until they reach the blastocyst stage (Day 5 or 6).
A highly skilled embryologist performs a biopsy, removing a few cells from the outer layer (trophectoderm).
The embryos are immediately cryopreserved via vitrification to maintain their integrity while testing occurs.
DNA is extracted from the biopsied cells and analyzed using Next-Generation Sequencing (NGS).
Geneticists review the data to categorize embryos as "euploid" (normal) or "aneuploid" (abnormal).
A healthy, screened embryo is selected, thawed, and transferred into the uterus during a subsequent cycle.
Types of PGT Innovations
PGT-A (Aneuploidy Screening)The most common screening, which checks for the correct number of chromosomes to prevent conditions like Down Syndrome.
PGT-M (Monogenic/Single-Gene)Highly specific testing for couples at risk of passing on a known inherited genetic mutation.
PGT-SR (Structural Rearrangements)Testing specifically designed for parents with chromosomal translocations, preventing imbalances in the offspring.
Next-Generation Sequencing (NGS)The modern gold standard in DNA analysis, allowing for the detection of mosaicism and subtle chromosomal deletions.
Non-Invasive PGT (niPGT)An emerging technique that analyzes the DNA released into the embryo’s culture media, avoiding the need for a physical biopsy.
AI-Enhanced Genetic InterpretationThe use of advanced algorithms to interpret complex sequencing data with greater speed and accuracy.
Pre-Procedure Preparation
Genetic counseling to discuss the implications of testing and the likelihood of finding healthy embryos.
Selection of an IVF protocol that prioritizes reaching the blastocyst stage for biopsy.
Detailed review of the legal and ethical framework under current ART (Regulation) Acts.
Coordination between the fertility clinic and the specialized genetics laboratory.
Financial and logistical planning for the additional time required for genetic analysis (typically 1–2 weeks).
Pre-Procedure Tests
Karyotyping of both parents to check for underlying chromosomal translocations or inversions.
Specific genetic carrier screening (Expanded Carrier Screening) to identify potential mutations.
Baseline IVF assessments, including AMH and AFC, to predict the number of embryos available for testing.
Semen analysis with DNA fragmentation testing to assess the risk of embryo-level abnormalities.
Validation of the "probe" or testing protocol if undergoing PGT-M for a specific family mutation.
Why This Treatment Is Highly Effective
Increases the success rate of a single embryo transfer to approximately 60–70% per attempt.
Dramatically reduces the risk of miscarriage by ensuring only chromosomally normal embryos are used.
Shortens the "time to pregnancy" by avoiding the transfer of embryos destined to fail.
Provides peace of mind to carriers of genetic diseases, knowing the condition will not be passed on.
Prevents the complications associated with multiple pregnancies by supporting the confidence in Single Embryo Transfer.
Recovery and Monitoring
The biopsy process does not affect the mother; recovery is tied to the standard egg retrieval or transfer timeline.
Embryos are monitored post-thaw to ensure they resume normal metabolic activity before transfer.
Recipients follow a standard FET (Frozen Embryo Transfer) protocol with hormonal support.
Progress is tracked via blood tests (Beta-hCG) and early ultrasounds to confirm successful implantation.
Genetic results are stored permanently in the patient’s record for future family building.
Life After PGT
Transition to routine prenatal care with a significantly lower risk of chromosomal complications.
Confidence in the long-term health and genetic foundation of the child.
Option to maintain cryopreserved "euploid" embryos for future siblings.
Ongoing gynecological follow-ups to maintain overall reproductive health.
Empowerment through the use of world-class technology to overcome complex fertility hurdles.