Embryo testing (PGT-M, PGT-SR, PGT-A)

Who it's for

• PGT-M: families with a serious inherited condition (e.g. cystic fibrosis, Huntington's) – over 2,000 conditions are approved
• PGT-SR: a parent carries a chromosome rearrangement
• PGT-A: sometimes offered after recurrent miscarriage or failed IVF – but see the HFEA rating

Key facts

• PGT-M and PGT-SR are medical treatments for specific conditions, licensed case by case by the HFEA.
• PGT-A is rated RED by the HFEA: for most patients it doesn't improve the chance of a baby and can reduce the number of embryos available.
• PGT-P (polygenic testing) is unlawful in the UK.
• Only some clinics offer embryo testing – use the 'Embryo testing' filter.

What happens

1. 1

   Genetic counselling

   To confirm the condition, your risks and whether it's approved for testing.

2. 2

   Test set-up

   For PGT-M, the lab designs a test for your family's specific mutation – this can take weeks.

3. 3

   IVF with biopsy

   Embryos are grown to day 5–6 and a few cells are biopsied. Embryos are usually frozen while results come back.

4. 4

   Transfer

   An unaffected embryo is transferred in a frozen embryo transfer.

How long it takes: Set-up can take 1–3 months, then an IVF cycle and a frozen transfer.

Success rates

• Depends on age and how many unaffected embryos there are. Ask clinics for PGT-M outcomes.

Each clinic's published rates – compared with the UK average – are on its profile in the clinic finder.

Costs

IVF cost plus test set-up and per-embryo testing – often several thousand pounds extra.

NHS funding

• PGT-M/PGT-SR can be NHS-funded (in England via NHS England's specialised commissioning) if you meet criteria – ask your clinical genetics team. PGT-A isn't NHS-funded.

Risks and side effects

• Biopsy may occasionally damage an embryo.
• No test is 100% accurate – prenatal testing is often still offered.
• There may be no unaffected embryos to transfer.