Pre-implantation genetic diagnosis (PGD) tests embryos created outside the body through IVF to determine whether a genetic disorder is present. It is carried out if a known specific disorder is at risk for being transferred to the baby.
Why Do People Have PGD?
Commonly cited reasons for patients undergoing Pre-Implantation Genetic Diagnosis (PGD) include:
- If one or both prospective parents is a symptomatic/asymptomatic carrier of a genetic disorder or chromosomal anomaly
- If the prospective mother is a carrier of an X linked chromosomal disorder
- A history of repeated miscarriages or a mature age
- An alternative to post-conception diagnostic procedures (amniocentesis) which can be followed with a difficult decision whether to terminate the pregnancy in the event of an unfavourable result
What Are The Benefits of PGD?
There are numerous benefits when it comes to undergoing this procedure, which includes:
- Helping to avoid future IVF or pregnancy failures as PGS will indicate if you have abnormal embryos. Alternatives can be considered beforehand
- Achieving pregnancy with as few IVF cycles as possible, which is often emotionally and financially beneficial
- Significantly reducing the risk of pregnancy with an abnormal embryo, which can occur in women of any age and may result in a miscarriage or failed treatment
What Are the Risks of PGD?
PGD is a very safe procedure, with minimal risk of embryo damage during the test. However, there are some risks to consider, which include:
- Risk of finding no embryos that are considered healthy
- There is a minimal chance that the test will not detect and remove a chromosomal abnormality entirely
- The procedure may be undertaken but may not be successful
What to Expect From the PGD Procedure:
- The ovaries are artificially stimulated using hormones to produce multiple eggs
- The eggs are removed and fertilised via IVF or sperm injection, depending on the genetic predisposition
- Successfully fertilised embryos are incubated in the laboratory for 5-6 days. This will allow the embryo to form a blastocyst, which will allow for a trophectoderm biopsy. This involves cells being taken directly from the embryo
- The cells are tested to determine whether the abnormality that causes the genetic condition originates from the embryo
- Embryos that do not have the chromosomal defect that was tested for, will be transplanted into the uterus
- Any remaining unaffected embryos can be frozen for future use
How Much Does PGD Cost?
- PGD from a single gene, performed privately in the UK, costs around £3,500.
- The NHS will cover up to three cycles of PGD and patients must qualify with strict criteria to be eligible.