Senior Consultant, Medical Genetics, Artemis Hospitals, Gurgaon, India
Part 11 of 12 in Finding Answers in Recurrent Pregnancy Loss
Pre-Implantation Genetic Testing: PGT-A, PGT-M, PGT-SR and PGT-HLA Explained
June 7, 2026
Pre-implantation genetic testing (PGT) analyses embryos, usually at the blastocyst stage, before transfer. PGT-A (aneuploidy screening) isn't recommended as routine in all IVF cycles, but may help in advanced maternal age, severe male factor infertility, or couples with a normal karyotype who've had recurrent miscarriage after IVF. PGT-M (monogenic) is used for single-gene conditions, both those causing recurrent loss, like hydrops or arthrogryposis, and later-onset conditions like thalassaemia or sickle cell anaemia, though all PGT results still need confirmation by prenatal testing, since PGT isn't considered 100% accurate.
PGT-SR (structural rearrangements) is the type most directly relevant to recurrent pregnancy loss: it's used for couples carrying a balanced translocation, selecting an embryo with a balanced or normal chromosome complement. PGT-HLA adds another layer: when a family already has a child needing a bone marrow transplant for a condition like thalassaemia or sickle cell disease, embryos can be selected that are both unaffected and an HLA match for that child, avoiding the ethical complications of prenatal HLA testing.
This guide is based on a live Jivo Masterclass — Dr. Kanika Singh taught doctors across Africa on June 7, 2026.
FROM THE LIVE Q&A
Dr. Isaya
My question is about sperm collection. In my clinic I often see couples where the male is over 50 years old. What are the chances of getting good quality sperm, and what are the implications for implantation?
Dr. Kanika Singh
I will not be able to give you details about specific sperm selection procedures, as in our hospital this is a multidisciplinary process involving the IVF specialist and the andrology laboratory. But in terms of the genetic implications: above the age of 50, there is a high chance that sperm quality is reduced, and the sperm DNA fragmentation index is likely to be elevated. Unless we specifically test for it, we do not know the exact level, but even without testing, there is a significant chance that sperm DNA quality is impaired, which can result in recurrent pregnancy loss or implantation failure. Testing the sperm DNA fragmentation index in men above 50 with a history of recurrent pregnancy loss or implantation failure would be worthwhile.
Frequently Asked Questions
For patients with PCOS, how long should metformin be taken before conception and after conception?▼
Metformin should be started at least 2 to 3 months before conception. It is safe to continue in pregnancy and is generally continued through the first trimester and sometimes beyond. It should be monitored with GTT as well as regular HbA1c and blood sugar checks throughout.
My question is about sperm collection. In my clinic I often see couples where the male is over 50 years old. What are the chances of getting good quality sperm, and what are the implications for implantation?▼
I will not be able to give you details about specific sperm selection procedures, as in our hospital this is a multidisciplinary process involving the IVF specialist and the andrology laboratory. But in terms of the genetic implications: above the age of 50, there is a high chance that sperm quality is reduced, and the sperm DNA fragmentation index is likely to be elevated. Unless we specifically test for it, we do not know the exact level, but even without testing, there is a significant chance that sperm DNA quality is impaired, which can result in recurrent pregnancy loss or implantation failure. Testing the sperm DNA fragmentation index in men above 50 with a history of recurrent pregnancy loss or implantation failure would be worthwhile.
When is PGT-A recommended?▼
PGT-A isn't recommended as routine in all IVF cycles, but may help in advanced maternal age, severe male factor infertility, or couples with a normal karyotype who've had recurrent miscarriage after IVF.
What conditions does PGT-M screen embryos for?▼
Single-gene conditions, both those causing recurrent loss, like hydrops or arthrogryposis, and later-onset conditions like thalassaemia or sickle cell anaemia.
Why do PGT results still need confirmation after transfer?▼
All PGT results still need confirmation by prenatal testing, since PGT isn't considered 100% accurate.
Which type of PGT is most relevant to couples with recurrent pregnancy loss from a balanced translocation?▼
PGT-SR, which selects an embryo with a balanced or normal chromosome complement.
What does PGT-HLA allow a family to do?▼
When a family already has a child needing a bone marrow transplant, embryos can be selected that are both unaffected and an HLA match for that child, avoiding the ethical complications of prenatal HLA testing.
In This Series: Finding Answers in Recurrent Pregnancy Loss
- 1.Finding Answers in Recurrent Pregnancy Loss
- 2.Fetal Chromosomal Abnormalities: The Leading Cause of First-Trimester Loss
- 3.Balanced Translocation: When a Genetically Normal Parent Passes on Recurrent Loss
- 4.Single-Gene Causes: Why Second-Trimester Losses Need a Different Genetic Workup
- 5.Anatomical Causes: Uterine Septum, Fibroids, and Cervical Incompetence
- 6.Antiphospholipid Antibody Syndrome: Diagnosis and Treatment
- 7.Endocrine Causes: Thyroid, PCOS, and Diabetes in Recurrent Pregnancy Loss
- 8.Sperm DNA Fragmentation: The Male Factor in Recurrent Pregnancy Loss
- 9.The Immunological Debate: NK Cells, TNF-Alpha, and IVIG Therapy
- 10.What to Test For: A Practical Investigation Framework by Trimester
- 11.Pre-Implantation Genetic Testing: PGT-A, PGT-M, PGT-SR and PGT-HLA Explained
- 12.Prognosis After Recurrent Pregnancy Loss: Why the Outlook Is Better Than Most Couples Expect