Genetic testing of embryos
Waterstone Clinic are the first Irish clinic to offer a successful embryo biopsy service in Ireland. Pre-implantation genetic testing (PGT) of embryos is a highly specialised laboratory technique performed as part of pre-implantation genetic diagnosis (PGD) and pre-implantation genetic screening (PGS).
First introduced in 2012, Waterstone Clinic were delighted to announce the first pregnancy and livebirth following embryo biopsy as part of pre-implantation genetic diagnosis (PGD) treatment.
PGD and PGS- What is the difference?
PGD or pre-implantation genetic diagnosis is reserved for couples at risk of or affected by a known genetic disorder. Following and IVF/ICSI cycle, the embryos are biopsied and the cells sent for genetic analysis. This detailed genetic analysis checks for the specific genetic condition. Only embryos that are unaffected by the condition will be selected for transfer into the woman’s uterus in a subsequent frozen embryo transfer cycle.
PGS or pre-implantation genetic screening involves screening the embryos for aneuploidy (extra or missing chromosomes) rather than a specific genetic condition. The risk of aneuploidy increases with increasing maternal age. This is more commonly recommended for:
- Recurrent implantation failure- repeated unsuccessful cycles of IVF where good quality embryos have been transferred.
- Recurrent miscarriage
- Advanced female age
Only euploid embryos (those with the correct chromosome number) will be selected for transfer into the woman’s uterus in a subsequent frozen embryo transfer cycle.
Both PGS and PGD require the female partner to undergo an IVF/ICSI cycle. The resultant embryos are cultured to blastocyst stage (day 5/6) when embryo biopsy is performed.
Embryo Biopsy & Embryo Transfer
An embryo biopsy involves making a small opening in the zona (shell), which surrounds the pre-implantation embryo. The biopsied cells are then sent for analysis to Genesis genetics (the genetic screening centre). The biopsied embryos are immediately cryopreserved to allow time for genetic analysis. The results are reported to Waterstone Clinic prior to embryo transfer.
Typically one embryo will be transferred into the female partner’s uterus using a fine tube or catheter. Any additional unaffected embryos remain in storage for future use in another treatment cycle.
What are my chances of success?
Approximately 1 in 3 couples who reach the stage of embryo transfer will have a livebirth.