PGD review from the perspective of the lead PGD nurse

thumbnail-2Our preimplantation genetic diagnosis (PGD) patients meet our lead PGD nurse, Karen Doye, as part of their treatment at CRGH. She also advises patients on other genetic screening tests, where indicated. Karen works closely with the HFEA for licensing and NHS England for funding purposes. She also liaises with external geneticists, scientists and the rest of the CRGH team to provide smooth and comprehensive patient care.

PGD is an exciting technique that allows us to identify chromosomal and genetic abnormalities in embryos before they are transferred to the womb, to implant and develop there. We use PGD to help eliminate the risk of couples transmitting a specific chromosomal or genetic disorder to their offspring.

When we asked Karen what was so exciting about working within PGD at CRGH, she quickly exclaimed, “karyomapping – and our contract with NHS England!”

Karyomapping is a relatively new technique that allows couples who are known to be carriers of an inherited condition to avoid passing it onto their baby. The process is a specialised diagnostic technique, which identifies the chromosomes of the mother, father, and reference (ie a child or other close relative of the couple) to track the genetic change (mutation) or chromosomal re-arrangement of concern through a family line. Karyomapping also has the advantage that it screens for chromosomal abnormalities which would otherwise cause a pregnancy to miscarry, and embryos with such an outlook will not be transferred, thus increasing the chance of a successful pregnancy resulting. Then the test is applied to a few cells biopsied from the developing embryo in order to identify embryos that are affected, thus enabling only embryos without the disorder to become a pregnancy and allowing a better chance of an unaffected baby to be born.


We are pleased that we also continue to offer PGD treatments to couples who do not have a suitable relative for karyomapping, by working on the mutation or chromosomal re-arrangement directly.

For the past several months, we have been freezing (by means of the technique of vitrification) embryos once they have been sampled (biopsied) at the blastocyst stage of development (reached 5- 6 days after fertilisation) while diagnosis is carried out and transferring a suitable embryo to the mother a few weeks later. This advance has resulted in significantly improved pregnancy rates, which is another cause of substantial pleasure for our team, as we see more couples fulfilling their hopes of the birth of a healthy baby, through our treatments.

Our contract with NHS England for PGD is a contract that very few fertility clinics in the UK have. Not all of our patients come to us through the NHS, but many of them do. After referral to us, Karen will ascertain whether a couple meets NHS England funding criteria and let them know during that first meeting. This means that there is no need to make any applications for NHS funding, so treatment is not delayed. We do not have any waiting lists, meaning that treatment can now usually commence within a very few weeks of receiving the referral letter from the clinical geneticist.

Karen’s involvement in our fertility treatments doesn’t stop with karyomapping and HFEA licensing, of course. She also works with our patients closely and forms bonds with couples who are hoping to have a baby and is privileged to keep in touch with families, sometimes over many years, through this pivotal time in their lives.

One of her favourite things each year is to receive Christmas cards from families she has worked with – and even better are all the photographs of babies that she’s helped bring about!

Like Karen, everyone at CRGH believes that it is an important thing we’re doing – and we are instrumental in people’s lives. It is a very special thing, which is not present in every profession, to play such a contributory role in the lives of our patients. After all, for many, without our fertility treatment and genetic testing, they would never have had their child!