PGT-A Embryo Genetic Testing: What It Is, What It Costs, and What It Can't Tell You
What PGT-A tests for, how it differs from PGT-M and PGT-SR, what mosaic results mean, and what the evidence says about its limits and costs.
Preimplantation genetic testing—PGT—isn't one test. It's three distinct tools for three different problems: chromosomal count, single-gene disorders, and structural rearrangements. Understanding which type applies to your situation, what the testing actually shows, and where its limits lie is essential before deciding whether it belongs in your IVF plan.
What is PGT-A and what does it test for?
PGT-A screens embryos for aneuploidy—having the wrong number of chromosomes. Most miscarriages and failed embryo transfers are caused by aneuploidy, making chromosomal abnormality one of the most common and significant barriers to a successful pregnancy. PGT-A is the most common form of embryo genetic testing and is used broadly with IVF cycles.
What is the difference between PGT-A, PGT-M, and PGT-SR?
PGT-A screens for aneuploidy—the overall chromosome count. PGT-M tests for a specific single-gene disorder when parents are known carriers; conditions commonly tested include cystic fibrosis, spinal muscular atrophy, sickle cell disease, Tay-Sachs, Fragile X, BRCA1/2, Huntington's disease, Lynch syndrome, and familial adenomatous polyposis. PGT-M requires a custom probe designed for the specific variant, which typically takes 6–12 weeks to build before the IVF cycle can start. PGT-SR is for couples where one partner carries a balanced chromosomal translocation or inversion—a structural rearrangement. The carrier is typically healthy, but their embryos often end up with missing or extra chromosome pieces; PGT-SR screens for those imbalances.
What does "euploid" mean when describing an embryo?
An embryo that has the correct number of chromosomes—one that PGT-A identifies as normal—is described as euploid. Aneuploidy rates increase sharply with maternal age: roughly 30% of embryos are aneuploid at age 30, about 50% at 35, around 70% at 40, and 80% or more at age 42. This age-related rise in aneuploidy is why per-transfer success rates decline as maternal age increases, and it is one of the primary reasons PGT-A is discussed more frequently in older patients.
Does PGT-A improve overall IVF success rates?
PGT-A reduces miscarriage risk per transfer and reduces the chance of transferring an embryo that won't implant or won't result in a viable pregnancy. It does not create more chromosomally normal embryos—it identifies which ones you already have. Your total cycle odds do not improve with PGT-A; your per-transfer odds do, by directing transfers toward embryos without chromosomal abnormalities.
Should everyone do PGT-A with IVF?
Whether PGT-A is the right choice depends on age, embryo count, known genetic risk, and individual priorities. The decision is best made with your REI based on your specific picture. PGT-A is not universally recommended for every IVF cycle—the benefit is most meaningful in populations where aneuploidy rates are high enough to substantially change transfer strategy. Bringing your specific questions to your provider is the right next step.
How much does PGT-A add to the cost of IVF?
PGT-A adds $3,000–$5,000 to an IVF cycle. PGT-M adds more—often $5,000–$10,000—because of the cost of designing a custom probe. PGT-SR runs in a similar range to PGT-M. Insurance coverage is limited but growing, particularly for PGT-M when there is a documented genetic indication.
What does a mosaic result mean on a PGT-A report?
Some embryos have a mix of normal and abnormal cells—this is called mosaicism. PGT-A may label these embryos as abnormal when they could still result in a healthy pregnancy. The test is accurate but not perfect, and mosaicism is one of the meaningful limitations of what PGT-A can determine about an embryo's actual potential.