PGD, now known as PGT-M (Preimplantation Genetic Testing for Monogenic Disorders), is an important option for couples with a known inherited genetic condition. It allows embryos created through IVF treatment to be tested before transfer, helping reduce the risk of passing specific genetic disorders to a child.
While PGT-M has transformed treatment for many families, it’s important to understand what it can—and cannot—do.
What Is PGT-M?
In PGT-M (formerly known as pre-implantation genetic diagnosis or PGD), a small number of cells are carefully removed from embryos created during IVF and tested for a specific inherited condition carried by one or both parents.
The aim is to identify embryos that are unaffected by the condition before embryo transfer.
PGT-M is commonly used for couples with known inherited disorders, helping reduce the risk of passing serious genetic conditions to their children.
Does PGT-M Improve IVF Success Rates?
Not directly.
The primary purpose of PGT-M is not to increase pregnancy rates, but to reduce the risk of passing on a known inherited condition.
However, for couples affected by genetic disorders, PGT-M can increase the likelihood of achieving a healthy pregnancy by allowing unaffected embryos to be selected for transfer.
How Is PGT-M Performed?
Modern embryo biopsy techniques have become increasingly refined over the years.
Research has also explored less invasive ways of analysing embryo DNA, including collecting genetic material released into the surrounding embryo fluid rather than relying solely on embryo biopsy. Studies such as this research into embryonic DNA continue to explore how embryo testing may become even less invasive in the future.
Although these approaches are promising, embryo biopsy remains the standard clinical method used for PGT-M today.
What Conditions Can PGT-M Detect?
The number of conditions PGT-M can screen for is extensive.
Hundreds of inherited disorders can be tested, including:
Cystic fibrosis
Sickle cell disease
Huntington’s disease
Muscular dystrophy
Tay-Sachs disease
Whether PGT-M is appropriate depends on the individual family’s medical history and specialist genetic counselling.
What Are the Limitations of PGT-M?
Although PGT-M offers significant benefits, it isn’t suitable for every patient.
Some of the limitations include:
The additional cost of treatment.
Not enough embryos may develop for testing.
Some embryos may not be suitable for transfer.
The emotional impact of receiving genetic results.
PGT-M cannot guarantee pregnancy or the birth of a healthy baby.
Are There Alternatives?
There are alternatives to PGT-M, although they are performed later in pregnancy.
Amniocentesis and CVS (chorionic villus sampling) are prenatal tests carried out during pregnancy, often when a genetic condition is suspected.
Depending on your circumstances, karyotype testing may also help identify chromosomal abnormalities before IVF treatment and, in some cases, reduce the need for embryo testing.
Optimising Your Chances of IVF Success
Genetic testing is only one part of preparing for IVF.
Couples shouldn’t neglect other important fertility investigations, including:
Hormone testing.
Semen analysis.
Ultrasound assessment.
Lifestyle factors also matter. Diet, smoking, alcohol, exercise and stress can all influence fertility and pregnancy outcomes.
Addressing these factors alongside appropriate genetic testing may help maximise your chances of a successful pregnancy.
Our Verdict
Not all inherited conditions are passed on, and not every couple needs PGT-M.
For families with a known genetic disorder, however, PGT-M remains one of the most important advances in reproductive medicine. It allows embryos to be screened before pregnancy, reducing the risk of passing serious inherited conditions to future children.
While PGT-M is an increasingly valuable option, it should be viewed as one piece of the fertility puzzle rather than a guarantee of IVF success. Combining appropriate genetic testing with thorough fertility investigations and expert clinical care offers the best chance of achieving a healthy pregnancy.