Understanding Preimplantation Genetic Diagnosis

What is PGD and how will it help me have a healthy baby?

We all want a healthy baby, one who grows into a healthy child. Unfortunately, in some cases it’s not always how things turn out. Certain genetic conditions can cause birth defects or start to show up as a child develops and certain factors, such as knowing you have a family history of a genetic disease or being of advanced maternal age, can increase the likelihood of your baby being affected.

Genea’s world leading Preimplantation Genetic Diagnosis (PGD) gives you a way of reducing or removing that risk.

In a standard IVF treatment, every time a cycle produces more than one embryo, a choice must be made about which embryo will be transferred. That choice is determined by the development and appearance of the embryos, usually over a five day period to work out which one has the best chance of achieving a pregnancy.

However, advances in scientific techniques mean PGD gives us another factor on which to base our decision - the genetic health of your embryo. PGD allows Genea scientists to base the choice on the results of genetic tests they’ve conducted on your embryos. These tests help us to rule out embryos that contain an obvious genetic abnormality. Testing can involve either a count of the chromosomes and/or a molecular examination for a particular gene or mutation.

PGD can increase the chances of a genetically normal embryo being selected, implanting successfully and your chance of carrying and delivering a healthy baby.

If you’re considering IVF, PGD could be an important part of the equation towards you achieving your dream. Learn more about the process of PGD and what is involved. 

Can we benefit from PGD?

PGD is recommended for you if you:

 
 
Are affected by or carry a known genetic disease
Are of advanced maternal age
Have had multiple miscarriages
Have had a number of failed embryo transfers
Want to prevent the transmission of a sex-linked genetic disease

PGD at Genea

Genea led the way in investigating and developing PGD in Australia and our expertise and techniques are amongst the best in the world. Genea first launched chromosome testing of embryos in 1995 and expanded that treatment to offering single gene testing in 1998. Our techniques have developed and expanded since we first conducted genetic testing and many clinics have followed our lead and modelled their tests on ours.

Genea was the first clinic ever to successfully introduce Preimplantation Genetic Diagnosis (PGD) successfully for Day 5 embryos in 1999, achieving the first baby ever born using this technique. A review of information from the Australian and New Zealand Assisted Reproduction Database (ANZARD) from 2004 to 2008 showed blastocyst biopsy for PGD improves both implantation and live birth rates when compared to biopsy at Day 3. The review showed clinical pregnancy rates from Day 5/6 biopsies were 29 per cent compared to 17 per cent for Day 3 biopsies and 23 per cent of couples undertaking Day 5 biopsy on their embryo delivered a baby compared to 13 per cent of couples whose embryo was biopsied at Day 3.

More than 2,000 single gene disorders have been identified and we are capable of building a test for any one of them. To date, we’ve been asked to test for approximately 200 disorders, more than any other clinic, and we’ve developed specific tests for each one, including some very rare disorders.

In 2012, another Australian IVF clinic stated that the holy grail for IVF technology would be the ability to test every one of the 23 chromosome pairs in the embryo before implantation. At Genea we have been doing just that since November 2009.

A couple of Australian clinics have recently begun promoting their “new” PGD technique - microarray Comparative Genome Hybridization (CGH) or microarray CGH. Genea was one of the first clinics in the world to adopt this technique and we’ve offered it to our patients for more than two years, since 2009. While standard chromosome tests can only detect some of these conditions, this more powerful high-resolution test can identify very small changes in chromosomes that standard tests are not able to detect.

Genea is one of the very few centres in Australia with the vital combination of IVF and genetics facilities to perform these sophisticated tests successfully. Quite simply, if you want to ensure that you benefit from the very latest assisted conception research and technology you could do no better than to come to Genea.

Please do not hesitate to contact one of Genea's PGD scientists should you have any questions.
Telephone: +61 2 9229 6420.

What are chromosome abnormalities?

What happens in PGD testing?

PGD testing involves carefully removing a small number of cells from an embryo for analysis. From this tiny sample, Genea is able to test whether an embryo has Down syndrome, cystic fibrosis, Huntington's disease or any of a wide range of other genetic problems. Each of these conditions needs to be tested for separately and we will discuss with you what conditions need to be considered.

Most commonly, PGD is used where a couple is aware of the possibility that their offspring will inherit a genetic disease. Even though they may not have a problem with infertility, the couple undergoes a stimulated IVF cycle with the aim of producing a number of embryos. Genetic material from these embryos is tested to see which, if any, of the embryos carries the genetic disease, and only embryos that do not show the disease are transferred to the woman’s uterus.

As we mentioned above, Genea’s approach to PGD - biopsy at blastocyst stage improves both implantation and live birth rates when compared to the biopsy at Day 3 method used by many other Australian clinics.

A review of information from the Australian and New Zealand Assisted Reproduction Database (ANZARD) from 2004 to 2008 showed 23 per cent of couples undertaking Day 5 biopsy on their embryo delivered a baby compared to 13 per cent of couples whose embryo was biopsied at Day 3.

PGD uses three major types of tests or analysis:

    •    Polymerase Chain Reaction (PCR);
    •    Comparative Genome Hybridisation (CGH); and
    •    Combination Polymerase Chain Reaction (PCR/CGH).

If you have or carry a diagnosed genetic problem or have suffered three or more miscarriages in a row, you can call us to discuss whether PGD is the right path for you. Genea is one of the very few centres in Australia with the vital combination of IVF and genetics facilities to perform these sophisticated tests successfully and help you achieve your ultimate dream - taking home a healthy baby.

Please do not hesitate to contact one of Genea's PGD scientists should you have any questions.
Telephone: +61 2 9229 6420.