Realising that you have an underlying genetic disorder which you do not want to risk passing onto your child is heartbreaking. However, with the almost-daily medical advances in IVF, inheritable conditions can be detected in the genes and/or chromosomes of embryos, created through IVF, eradicating the possibility of passing those conditions on.
IVF babble is here to guide you with comprehensive information on your journey and how to boost your chances for a successful outcome.
Here are the paths to parenthood to help you to explore your options both using your own embryos or in some cases donor eggs and/or sperm. Click on the paths below to find out more information.
Pre implantation genetic diagnosis enables people with an inheritable condition in their family to avoid passing it on to their children. It can be used to test for virtually any genetic condition where a specific gene is known to cause that condition. It is
currently approved to screen for over 250 genetic conditions.
With PGD, there is also the possibility that some embryos may be damaged by the process of cell removal and is not always 100% reliable or conclusive.
The procedure for PGD is usually as follows:
Step 1. You undergo normal in vitro fertilisation (IVF) treatment to collect and fertilise your eggs.
Step 2. The embryo is grown in the laboratory for two to three days until the cells have divided and the embryo consists of around eight cells.
Step 3. A trained embryologist removes one or two of the cells (blastomeres) from the embryo.
Step 4. The cells are tested to see if the embryo from which they were removed contains the gene that causes the genetic condition in the family.
Step 5. The embryo unaffected by the condition is transferred to the womb to allow it to develop.
Step 6. Any suitable remaining unaffected embryos can be frozen for later. Those embryos that are affected by the condition are allowed to perish or, with your consent, used for research.
It is possible that, instead of removing and testing one or two cells from a two to three-day- old embryo, some clinics may allow the embryo to develop to five to six days, when there are 100-150 cells.
At this stage, cells within an embryo have separated into two types: cells which will form the fetus (inner cell mass) and cells which will form the placenta (trophectoderm).
More cells can be removed at this stage (from the trophectoderm) without compromising the viability of the embryo, possibly leading to a more accurate test.
The possible success rate of having a baby using PGD
It is difficult to assess success rates for PGD because there is currently little data available. Most women use this treatment not because they have fertility problems but because they want to avoid having a child with a genetic disease.
As with most fertility treatments, success depends on many factors, including the woman’s age and whether a cause of infertility has been identified.
Sometimes no embryos are suitable for transfer to the womb, for reasons including:
not enough eggs are produced or fertilised in the first place
removing the cells to be analysed damages the embryos
all the embryos are affected by the genetic disease.
In 2010 (the year for which the most recent data is available) 311 women received 383 cycles of PGD. This resulted in 121 live births (live birth rate of 31.6% per cycle started).