What is Preimplantation Genetic Testing (PGT)?
Preimplantation Genetic Testing (PGT) is one of the most advanced assisted reproductive technologies. Built on standard IVF, it adds genetic testing of embryos so doctors can select embryos with normal chromosomes and without inherited diseases before embryo transfer.
The three types of PGT
PGT-A (chromosome aneuploidy screening)
Checks whether the embryo has the correct number of chromosomes (46 in 23 pairs). Chromosomal abnormalities are a leading cause of recurrent miscarriage and IVF failure. PGT-A can identify over 99% of aneuploid embryos.
PGT-M (single-gene disorder testing)
Targets known single-gene conditions such as thalassemia, spinal muscular atrophy (SMA), and cystic fibrosis, and accurately screens embryos that carry the disease-causing gene.
PGT-SR (chromosomal structural rearrangement testing)
Detects balanced translocations, inversions, and other structural changes; suitable for couples with known chromosomal structural variants.
Who is PGT for?
- Women age 35 and older
- Recurrent miscarriage (two or more losses)
- Repeated IVF embryo transfer failures (three or more)
- One or both partners carry a genetic condition
- Previous child with a chromosomal abnormality
- Families needing sex selection to prevent sex-linked genetic disease
PGT step-by-step process
- Initial evaluation: Both partners complete genetic testing and a fertility assessment; we create a personalized plan.
- Stimulation and egg retrieval: The woman takes 10–14 days of ovarian stimulation, then eggs are retrieved.
- Fertilization and culture: After IVF/ICSI, embryos grow to the blastocyst stage (about days 5–6).
- Embryo biopsy: A few cells are gently taken from the blastocyst for genetic testing; this does not harm the embryo.
- Freeze and wait: Embryos are frozen while we await results (about 2–4 weeks).
- Transfer a healthy embryo: We select an embryo confirmed as normal for embryo transfer.
Success rates
Vivia IVF partner clinics use the latest generation of PGT, with top-quality laboratories and experienced embryologists:
- Blastocyst formation rate: 65–75%
- PGT accuracy: >99%
- Clinical pregnancy rate with a normal embryo transfer: >65%
- Cumulative success rate (2–3 transfers): >90%
FAQs
Does PGT harm the embryo?
No. Modern PGT samples a few trophectoderm cells at the blastocyst stage (which become the placenta) and does not affect the inner cell mass (which becomes the baby), so embryo development is not impacted.
Can PGT guarantee a 100% healthy baby?
PGT can screen for specific genetic abnormalities, but no test can rule out all possible health risks 100%. PGT greatly reduces the risk of genetic disease and miscarriage, but routine prenatal care is still recommended after pregnancy.