PGT-M Explained: Testing Embryos for Genetic Conditions

Preimplantation genetic testing for monogenic diseases (PGT-M) screens embryos for specific single-gene conditions before an embryo transfer, identifying which embryos inherited a known gene mutation and which are unaffected.

Facing genetic uncertainty after carrier screening or an infertility diagnosis can make family building feel daunting. PGT-M provides actionable clarity early in your IVF cycle, allowing you to move forward using your own gametes or donor eggs.

If you choose to work with a surrogacy agency like American Surrogacy, specialists coordinate with genetic counselors to align your testing protocol with your broader family-building goals. Learn more about preparing for your fertility journey.

What Is PGT-M?

PGT-M is a targeted genetic screening performed during IVF to detect single-gene disorders in early embryos. It analyzes precise DNA sequences to identify specific gene alterations passed down through families.

Embryologists remove 3 to 10 outer cells from day 5 or 6 blastocysts, leaving the inner cell mass untouched. After safely freezing the embryos, tissue samples go to a specialized genetics lab where DNA is tested against your custom probe to identify unaffected, carrier or affected embryos.

What Does PGT-M Test For?

PGT-M tests for thousands of single-gene conditions caused by specific gene alterations. It doesn't screen for multi-factor conditions like autism or heart disease, which involve complex combinations of genetic and environmental factors.

Genetics laboratories design custom PGT-M probes to identify single-gene disorders across several primary categories:

Autosomal Recessive Conditions: Conditions like cystic fibrosis, sickle cell anemia, Tay-Sachs disease and spinal muscular atrophy (SMA), which require both parents to pass on a mutation.
Autosomal Dominant Conditions: Conditions like Huntington's disease, Marfan syndrome and Myotonic dystrophy, where inheriting a single mutated gene from one parent causes the condition.
X-Linked Conditions: Conditions carried on the X chromosome like Duchenne muscular dystrophy and Hemophilia A, which affect male offspring more severely.
Hereditary Cancer Syndromes: Inherited cancer risks associated with BRCA1, BRCA2 and Lynch syndrome gene mutations.

These categores include specific conditions like:

Hemophilia

Cystic fibrosis

Huntington's disease

Sickle cell anemia

Muscular dystrophy

Who Should Consider PGT-M?

PGT-M is recommended when prospective intended parents have an identified risk of passing a known single-gene condition to their children.

Your reproductive endocrinologist or genetic counselor may recommend PGT-M in several common clinical situations:

Both you and your partner test positive as carriers for the same autosomal recessive condition.
You or your partner carry an autosomal dominant genetic condition.
A parent carries an X-linked genetic mutation.
You or your partner carry a hereditary cancer gene mutation.
You have a previous child or family history with a severe single-gene disorder.

PGT-M vs. PGT-A: What's the Difference?

PGT-M screens for specific inherited single-gene mutations, whereas PGT-A evaluates overall chromosomal counts across all 23 chromosome pairs. Many intended parents choose to run both tests simultaneously on a single embryo biopsy.

Key differences between PGT-M and PGT-A include:

Primary Focus: PGT-M targets known hereditary single-gene conditions, while PGT-A checks for random numerical chromosomal gains or losses (aneuploidy).
Clinical Indications: PGT-M serves prospective intended parents with identified genetic carrier status or family disease history. PGT-A helps address concerns related to advanced maternal age, unexplained pregnancy loss or repeated transfer setbacks.
Testing Requirements: PGT-M relies on custom-designed genetic probes built around your family's unique DNA sequence. PGT-A uses standardized high-throughput sequencing without requiring custom probe design.
Detection Scope: PGT-M checks exclusively for your specific targeted gene alteration, whereas PGT-A assesses all 23 pairs of chromosomes.

Combining both screenings helps your care team identify embryos that are both chromosomally balanced and free of specific inherited conditions. Learn more about numerical chromosomal screening in our detailed PGT-A testing guide.

How the PGT-M Process Works: Step-by-Step

Creating embryos tested with PGT-M requires careful coordination between your IVF clinic and a specialized genetics laboratory. The entire preparation and testing sequence typically takes 8 to 12 weeks before embryo transfer.

Step 1: You and your partner (or donor) complete comprehensive carrier screening to identify specific gene mutations.

Step 2: The genetics lab builds a unique molecular test (probe) using DNA samples from you, your partner and sometimes family members, taking 4 to 8 weeks.

Step 3: The female partner or egg donor undergoes ovarian stimulation and egg retrieval to create embryos.

Step 4: Embryos grow to day 5 or 6 blastocysts, where embryologists biopsy a few trophectoderm cells from each viable blastocyst.

Step 5: Biopsied embryos are safely frozen at your clinic while tissue samples are shipped to the genetics laboratory.

Step 6: The lab analyzes the DNA samples using your custom probe and provides a detailed report classifying each embryo as unaffected, carrier or affected.

Step 7: Your physician reviews the report with you to select an unaffected embryo for transfer into the prospective mother or gestational surrogate.

How Accurate Is PGT-M?

PGT-M has diagnostic accuracy rates between 98% and 99% when performed by accredited genetics laboratories. Modern testing techniques like next-generation sequencing (NGS) minimize diagnostic errors.

Despite high accuracy, clinical protocols account for potential biological and technical limitations:

Diagnostic Margins: Rare technical errors or allele dropout (ADO) can occur during DNA amplification, which is why prenatal diagnostic testing (CVS or amniocentesis) is offered during pregnancy for confirmation.
Inconclusive Results: Occasionally, a sample doesn't yield enough clear genetic data, which means your care team may discuss a secondary review or re-biopsy.
Mosaicism Risks: Trophectoderm cells occasionally differ genetically from the inner cell mass, though this is less common with monogenic single-gene testing than chromosomal checks.

PGT-M and IVF Success Rates

PGT-M focuses on preventing inherited conditions rather than changing overall embryo quality or uterine readiness. Because of this, pregnancy success still depends on standard IVF factors like maternal age, embryo grade and clinical timing.

Selecting an unaffected embryo ensures that your child won't inherit the targeted genetic condition. When combined with PGT-A to verify chromosomal balance, transferring a screened, high-grade embryo gives you the strongest chance for a healthy pregnancy and delivery.

How Much Does PGT-M Cost?

The cost of PGT-M typically ranges from $3,000 to $7,000 in addition to standard IVF cycle fees. Because PGT-M requires custom probe development, it carries higher costs than standard chromosomal screening.

Key cost components for PGT-M testing include:

Custom Probe Design Fee: $1,500 – $3,000 (one-time fee per family mutation).
Embryo Biopsy Fee: $1,500 – $2,500 (charged by your fertility clinic).
Genetics Lab Analysis Fee: $1,000 – $2,500 (covers a set number of embryos, often up to 8).
Storage & Vitrification Fees: $500 – $1,200 annually.

Insurance coverage for PGT-M varies significantly by provider and state mandates. Many insurance plans cover initial carrier screening and probe design if you have a documented medical history of a severe genetic condition.

Full-service surrogacy agencies evaluate these clinical costs alongside overall cycle planning to ensure no unexpected lab fees disrupt your budget. Speak with an American Surrogacy specialist to learn how financial planning works during a surrogacy journey.

What Happens If IVF Isn't Successful?

If transfer attempts haven't resulted in pregnancy despite healthy PGT-M screened embryos, surrogacy offers a clear path forward. Uterine factor challenges or medical risks can prevent successful gestation even with healthy embryos.

Pairing your embryos with a pre-screened gestational surrogate bypasses uterine factors while preserving your genetic connection.

Partnering with American Surrogacy protects your investment through our Limited Risk Program, offering unlimited rematching without repeating agency fees. Combined with our 1–6 month average match time, you can move forward without losing momentum.

Talk With American Surrogacy About Your Next Steps

Whether you have frozen PGT-M embryos or are preparing for an upcoming cycle, we're here to guide your next steps.

Our team supports prospective intended parents through every stage of family building, providing clear answers, experienced guidance and financial protection.

Contact a surrogacy specialist today or call 1-800-367-2362 to protect your journey to parenthood.