Preimplantation Genetic Diagnosis (PGD): Ensuring a Healthy Pregnancy

What Is PGD?

Preimplantation Genetic Diagnosis (PGD) is an advanced reproductive technology used during IVF to identify genetic or chromosomal abnormalities in embryos before implantation. This screening process helps select the healthiest embryos, increasing the chances of a successful pregnancy and reducing the risk of passing on inherited diseases.

PGD is particularly beneficial for couples with a family history of genetic disorders, women experiencing recurrent miscarriages, or those undergoing IVF at advanced maternal age.

Who Should Consider PGD?

PGD can be used in all IVF cycles, but it is especially recommended for:

Couples at risk of passing on genetic diseases (e.g., cystic fibrosis, sickle cell anemia).
Women over 38 years old, as embryo abnormalities increase with age.
Couples who have had multiple miscarriages due to chromosomal issues.
Men with severe sperm abnormalities, which may lead to embryo genetic defects.
Individuals carrying chromosomal rearrangements, ensuring a balanced genetic profile in embryos.

By screening embryos before implantation, PGD improves IVF success rates, reduces pregnancy loss, and helps parents have a healthy baby free of genetic conditions.

Trophectoderm Biopsy: How PGD Works

A trophectoderm biopsy is performed on embryos at the blastocyst stage (typically Day 5 or 6 of development). This procedure allows embryologists to extract 5-6 cells from the outer layer (trophectoderm) without harming the embryo, ensuring both accuracy and safety.

The PGD Process Step-by-Step

Embryo Development: After fertilization, embryos are cultured in a lab for five to six days until they reach the blastocyst stage.
Biopsy Procedure: Using laser-assisted technology, embryologists carefully remove a few trophectoderm cells for genetic testing.
Genetic Screening: The extracted cells undergo advanced genetic testing methods such as NGS (Next-Generation Sequencing) to detect:

• Chromosomal abnormalities (PGT-A)
• Single-gene disorders (PGT-M) Embryo Freezing (Vitrification): After biopsy, embryos are frozen and stored while genetic testing results are analyzed.
  Embryo Selection & Transfer: Once the healthiest embryo is identified, it is prepared for Frozen Embryo Transfer (FET) to maximize implantation success.

Why Is Trophectoderm Biopsy Important?

Higher Implantation Rates – Selecting only chromosomally healthy embryos increases pregnancy success.
Reduced Risk of Miscarriage – Eliminating embryos with abnormal chromosomes prevents pregnancy loss.
Lower Risk of Genetic Disorders – PGD helps prevent hereditary diseases from being passed to the baby.
Shorter Infertility Treatment Duration – By transferring only the best-quality embryo, PGD minimizes the need for multiple IVF cycles.

Advanced Genetic Testing Methods

PGD results are obtained using cutting-edge technologies such as:

NGS (Next-Generation Sequencing): The most advanced method, providing high-precision chromosome analysis.
FISH (Fluorescence In Situ Hybridization): Used for detecting specific chromosomal abnormalities.
PCR (Polymerase Chain Reaction): Identifies single-gene disorders (e.g., Huntington’s disease).
CGH (Comparative Genomic Hybridization): Screens for genetic imbalances in embryos.

What Happens After PGD?

Healthy embryos are identified and stored safely in liquid nitrogen until transfer.
The best embryo is selected for transfer, maximizing implantation potential.
Parents have peace of mind knowing their baby is free of genetic conditions.

Considering PGD for your IVF cycle? Consult with a fertility specialist today to explore how genetic screening can help you achieve a healthy pregnancy!