Genetic screening is currently available through a link with Reprogenetics in Oxford. If you’d like to discuss the genetic diagnosis options available to you for your IVF cycle, please contact us.
Chromosomal abnormality is one of the most common causes of unsuccessful pregnancy. If an embryo has too many or too few chromosomes (a condition called aneuploidy) this can have a serious effect on its chances of developing normally into a fetus and then a baby. In many cases, embryos with the wrong number of chromosomes stop growing by themselves, and this unfortunately often results in miscarriage.
This is no less common with IVF treatment. However, the IVF process enables us to monitor the development of multiple embryos at the same time. We can provide various levels of genetic screening during treatment, to help us select embryos with normal chromosomes, which have the best chance of developing into a healthy pregnancy.
The pre genetic screening we offer is Next Generation Sequencing from embryo biopsy.
The first few stages of an IVF cycle that involves PGS are no different from any other.
The embryos that develop will be examined and you will be advised if they are suitable for biopsy which will take place on day 5 or day 6. A small sample of cells (called a biopsy) within the embryo are taken using a needle. The sample of cells is called a biopsy and we make sure that we take this from the cells which will go onto make the placenta so that we do not damage the cells that will make the baby. The biopsy samples are placed in tubes and sent to the genetics laboratory. The genetic test takes 4 weeks to process so your embryos are frozen until we have the result.
Scientists working in the laboratory carry out the PGS test on all of the samples received. The test results indicate how many copies there are of each chromosome, revealing any abnormal embryos. PGS does not require additional blood tests prior to the IVF cycle. Once the results are known your follow up appointment will be confirmed.
Genetic mutations, sometimes passed down from parents, are another cause of unsuccessful pregnancy. Pre-implantation genetic diagnosis is used when a serious genetic disease could be passed from parent to child. There are two techniques: karyotyping, and conventional pre-implantation genetic diagnosis. We are particularly pleased to be able to offer karyomapping as, unlike with conventional PGD, embryos can be screened for chromosomal abnormalities as well as a certain genetic mutation, thus increasing the likelihood of a healthy on-going pregnancy. Conventional PGD is used where the mutation is new and not present in either of the parents, or where we are unable to obtain DNA from other family members who have the same genetic mutation.
Pre-implantation genetic diagnosis can also help couples who have discovered that they have a balanced translocation or inversion. A special high-resolution Array Comparative Genomic Hybridisation test can be used to select normal embryos.
The first few stages of an IVF cycle that involves PGD are no different from any other.
After the eggs are collected, they are fertilised using intracytoplasmic sperm injection (ICSI). The use of ICSI reduces the risk of DNA contamination derived from sperm.
After growing the embryos for 5 days some cells are removed and sent to the genetic laboratory. The cells are analysed for the gene disorder, and the embryos are vitrified (frozen) until the test results are available. Scientists working in the Reprogenetics laboratory carry out the test on all of the samples received and provide the results 24 hours later. Embryos that are unaffected can then be transferred as with the any other IVF journey.
Key features of the single-gene PGD service
If you’d like to discuss the genetic diagnosis options available to you for your IVF cycle, please contact the clinic .
*Disorders must be licensed for testing by the HFEA.
A full list of disorders is available at: http://www.hfea.gov.uk/cps/hfea/gen/pgd-screening.htm or contact us for advice.