PGT-A vs PGT-SR for Male Factor Infertility: Key Differences

Understanding PGT-A and PGT-SR

When you are exploring fertility treatment and male factor infertility is part of the picture, you may come across two types of preimplantation genetic testing: PGT-A and PGT-SR. Both are performed on embryos created through IVF before a transfer is considered. However, they look for different things and are used in different situations.

PGT-A (preimplantation genetic testing for aneuploidy) screens embryos for the correct number of chromosomes. PGT-SR (preimplantation genetic testing for structural rearrangements) looks for specific structural changes in chromosomes, such as inversions or translocations, that a parent may carry. Understanding the difference can help you ask the right questions and make informed decisions with your fertility team.

At a Glance

• PGT-A checks for extra or missing chromosomes (aneuploidy).
• PGT-SR checks for balanced or unbalanced structural rearrangements.
• Male factor infertility may increase the chance of sperm carrying chromosomal abnormalities.
• Neither test guarantees a pregnancy or a healthy baby.
• Your clinic can advise whether one or both tests are relevant for your situation.

What Is PGT-A?

PGT-A is a test that looks at the number of chromosomes in an embryo. Humans typically have 46 chromosomes in each cell, arranged in 23 pairs. An embryo with too many or too few chromosomes is called aneuploid. Most aneuploid embryos fail to implant or result in miscarriage. PGT-A can identify embryos that have the expected number of chromosomes, which may be prioritized for transfer.

PGT-A is often recommended for women of advanced maternal age, but it can also be considered when there is a history of recurrent miscarriage or repeated implantation failure. In the context of male factor infertility, sperm with abnormal shape or movement may carry a higher rate of chromosomal abnormalities, which can contribute to aneuploidy in embryos.

What Is PGT-SR?

PGT-SR is designed for couples where one or both partners carry a structural rearrangement of their chromosomes. Structural rearrangements include translocations (when a piece of one chromosome attaches to another) and inversions (when a segment of a chromosome is reversed). These rearrangements may not affect the health of the carrier, but they can lead to embryos with unbalanced chromosomes, which may cause miscarriage or a child with disabilities.

PGT-SR tests embryos to identify those with a balanced set of chromosomes, meaning they have the same arrangement as the carrier parent or a completely normal arrangement. This can help reduce the risk of miscarriage and the chance of passing on an unbalanced rearrangement.

How Male Factor Infertility Relates to Chromosomal Abnormalities

Male factor infertility is often related to sperm count, motility, or morphology. However, some men with infertility may also have chromosomal abnormalities, such as a translocation or an extra sex chromosome. Even without a diagnosed rearrangement, sperm with poor parameters may have a higher rate of chromosomal abnormalities, including aneuploidy.

If a man carries a structural rearrangement, PGT-SR may be relevant. If there is no known rearrangement, PGT-A might be considered to screen for aneuploidy. Your fertility specialist can help determine which test, if any, is appropriate based on your medical history and diagnostic testing.

Key Differences Between PGT-A and PGT-SR

Aspect	PGT-A	PGT-SR
What it screens for	Number of chromosomes (aneuploidy)	Structural changes (translocations, inversions)
Who might consider it	Couples with advanced maternal age, recurrent miscarriage, or male factor with suspected aneuploidy	Couples where a parent carries a structural rearrangement
How it works	Analyzes all chromosomes for copy number	Analyzes specific chromosomal regions for balanced/unbalanced arrangement
What it can tell you	Whether an embryo has the expected number of chromosomes	Whether an embryo has a balanced or unbalanced structural arrangement
Limitations	Cannot detect all genetic conditions; may have false positives/negatives	Cannot detect all genetic conditions; may not identify all rearrangements

When Might PGT-A or PGT-SR Be Recommended?

Your fertility team may suggest PGT-A if you have experienced recurrent pregnancy loss, previous aneuploidy, or if the female partner is of advanced maternal age. In male factor infertility, PGT-A might be considered if sperm analysis shows high DNA fragmentation or if there is a history of chromosomal abnormalities in the male partner.

PGT-SR is typically recommended when a blood test (karyotype) has identified a structural rearrangement in either partner. If you have not had a karyotype test, your doctor may suggest one if there is a history of multiple miscarriages or a family history of chromosomal rearrangements.

What PGT Cannot Do

It is important to understand that PGT-A and PGT-SR are screening tests, not guarantees. They cannot ensure a pregnancy will occur, nor can they guarantee a healthy baby. Embryos that appear normal by these tests may still fail to implant or may have other genetic or developmental issues. Additionally, PGT does not eliminate the risk of miscarriage entirely.

These tests also have technical limitations. For example, they require a biopsy of a few cells from the embryo, which may not represent the entire embryo (mosaicism). There is also a small risk that the biopsy could damage the embryo, though this is rare. Your clinic can explain the specific limitations and accuracy of the testing platform they use.

Questions to Ask Your Clinic

• Based on our history, is PGT-A or PGT-SR recommended for us?
• What is the difference in cost between PGT-A and PGT-SR?
• How many embryos are typically needed for testing to be worthwhile?
• What is the accuracy of the testing method you use?
• How will the results be reported, and who will explain them to us?
• Are there any additional tests we should consider, such as sperm DNA fragmentation testing?

Next Steps

1. Review your medical history with your fertility specialist, including any previous pregnancy outcomes.
2. Ask about genetic carrier screening and karyotype testing for both partners.
3. Discuss whether PGT-A, PGT-SR, or both are appropriate for your situation.
4. Understand the process, timeline, and costs involved.
5. Make an informed decision based on your personal goals and medical advice.

For more information about PGT in Thailand, visit our PGT in Thailand page. You can also explore our guides and FAQ sections for additional insights.

Frequently asked questions

Can PGT-A detect structural rearrangements like translocations?

PGT-A is designed to detect aneuploidy (extra or missing chromosomes). It may not reliably detect balanced structural rearrangements, which is what PGT-SR is designed for. If a parent carries a translocation, PGT-SR is typically recommended.

Is PGT-SR only for women?

No, PGT-SR can be used when either partner carries a structural rearrangement. Male factor infertility may be linked to such rearrangements, so PGT-SR can be relevant for couples where the male partner is a carrier.

Does male factor infertility always require PGT?

No. PGT is not automatically required for male factor infertility. Your doctor will assess your specific situation, including sperm parameters, genetic testing results, and medical history, to determine if PGT-A or PGT-SR is beneficial.

What is the difference between PGT-A and PGT-SR in terms of cost?

Costs can vary between clinics and depend on the number of embryos tested. PGT-SR may be more expensive because it requires more detailed analysis. You should ask your clinic for a detailed cost breakdown.

Continue your research

• PGT in Thailand overview
• PGT and IVF guides
• Frequently asked questions

Medical information notice: This article is educational and does not replace individual assessment, diagnosis, genetic counselling or treatment advice from a licensed clinician. Provider services, availability, fees and policies should be verified directly before booking.