PGD (Preimplantation Genetic Diagnosis)
Pre-implantation genetic diagnosis (‘PGD’) was developed in the early 1990s. It is a diagnostic method that enables would-be parents to avoid the risk of passing on a known genetic condition to their children
CRGH was an early pioneer of PGD in the UK, initially in collaboration with University College London (UCL). CRGH has had many national firsts including the first babies born free from the following inherited cancer predispositions; eye cancer (Retinoblastoma), bowel cancer (Familial Adenomatous Polyposis Coli) and breast cancer (BRCA1).
Who is it for?
Today, CRGH uses PGD to support patients for a wide variety of inheritable conditions, including:
- Sickle cell disease
- Cystic fibrosis
- Inheritable cancer pre-dispositions
- Huntingdon’s Disease
- Muscular dystrophies
Another common indication for PGD is rearrangements in chromosomes. We also offer PGD to avoid rare conditions such as Harlequin Icthyosis. If the condition has not previously been undertaken with PGD in the UK, we are willing to apply to our regulator, the Human Fertilisation and Embryology Authority (HFEA) to seek permission to treat.
How does it work?
PGD involves taking eggs and sperm from the intending parents (or sometimes from a donor) and achieving fertilisation in the laboratory (Please see our IVF/ICSI web page). The resulting embryos are allowed to develop for five to six days. These embryos are termed as blastocysts. A small number of cells is taken from the embryos (biopsy). They are tested for the specific genetic conditions or chromosomal rearrangement, using the test which has been specifically prepared for each couple. The embryos are frozen. One (or sometimes two) suitable embryo(s) may be transferred to the womb. If the PGD treatment is successful, the pregnancy may proceed with normal antenatal care.
How do I access PGD testing?
NHS funded patients should seek referral to the CRGH from a geneticist in their local area. Regional genetic services cover all areas of the UK. NHS funding is immediately available if couples meet the national criteria set by the NHS ( NHS criteria doc ).
For private patients (including those from overseas), who have not previously been seen by a Genetic Counsellor or doctor, we are able to offer private consultations with our dedicated Genetic Counsellor, Sara Levene, prior to the start of the PGD process. At this consultation Sara will take an initial history and will you advise on the appropriateness of PGD, versus other reproductive options. If further genetic testing is required to assess the appropriateness of PGD, Sara can arrange this.
For private patients where the genetic diagnosis needs further assessment before PGD can be considered, Sara may recommend an appointment with a private Clinical Geneticist (a doctor specialising in genetic conditions) prior to further PGD consultations.
What is the process?
You will be seen by our Genetic Counsellor for a PGD consultation. A fertility assessment check will be carried out and necessary laboratory PGD work up will be prepared. You will then be seen by a Consultant Gynaecologist and an IVF nurse to discuss your treatment. Your PGD treatment will start once the laboratory work up is ready.
Can I choose the sex of my child?
We are from time to time asked to provide information which would allow parents to select the gender of their prospective child. We cannot provide such information since sex selection is illegal in the UK.
PGD Success Rates at CRGH
Since 1996, the Centre for Reproductive and Genetic Health (CRGH) has offered patients a full range of highly specialist PGD services, and achieved many national firsts in the field. These include the first baby conceived free of the breast cancer gene, the first baby born free of retinoblastoma (a form of eye cancer) and the first centre to test for Familial Adenomatous Polyposis (FAP) which can lead to early onset colon cancer. CRGH was the first unit in Europe to achieve a live birth using Karyomapping.