Most women and couples at high risk of breast or ovarian cancer choose, with their partner, to have children in the same way as most other couples.
However some people wish to understand more about their family planning options. Most of the options available are for men and women with defined gene mutations. People interested in exploring these options generally do so as they wish to have a child in the knowledge that he/she will not have an increased risk associated with the defined gene mutation later in life.
This section provides an introduction to family planning options. A Genetics Clinic and/or specialist In Vitro Fertilization (IVF) clinics can provide more detailed information about these options.
The most common family planning option explored by men and women with a defined gene mutation causing an increased risk for breast and ovarian cancer is called Preimplantation Genetic Diagnosis (PGD). There are other options on page 78.
What is PGD?
Preimplantation genetic diagnosis (PGD) is a technique used to test the genetic information of an embryo. PGD can be used to test for a specific high risk gene mutation in an embryo to distinguish between embryos that have inherited the high risk gene mutation and those that have not.
For PGD to take place, embryos are required to be made via an IVF process. This means taking eggs and sperm and creating an embryo outside the womb (uterus). Following creation of the embryo, it is then screened for the particular gene fault and then frozen. Once the test has been completed an embryo is only transferred to the womb if the embryo;
- Does not have the gene fault
- Is thawed successfully
Any additional embryos remain frozen and may be available to be used by that couple at a later date.
The technology used to test the embryos is different to genetic testing done in adults. Tests will need to be done before PGD can be offered. These generally involve the collection of blood or saliva samples from other relatives to look for linked DNA markers that are pointers to the gene mutation being present. If samples from other relatives are not available, it may still be feasible to offer PGD testing using a different DNA testing technique.
What to ask?
There are many aspects and costs involved in this process so it is important to make sure you have all the information you need to make a decision that is best for you.
Questions people may wish to ask include;
○ Are there any risks for the woman having IVF?
○ What are the chances of creating embryos for testing, chances for creating an embryo without the specific gene mutation and chances the implanted embryo will go onto be a successful pregnancy?
○ How does this compare to conceiving and having a successful pregnancy without using IVF/PGD?
○ How will the embryo be tested? Do I need to involve other relatives and who would they be?
○ How long does it take to work up the tests for PGD?
○ Will the PGD test screen embryos for anything else?
○ How much does it cost? Note PGD is not covered by Medicare or Private Health Insurers.
What are the other family planning options?
There are other family planning options. One type is known as prenatal testing, this is the testing of the genetic material of the foetus in the womb, and samples used for testing include either placental tissue or fluid around the foetus for a genetic mutation.
Another option includes the use of donor eggs (or donor sperm where a male partner is affected). A Familial Cancer Clinic or specialist prenatal genetic clinic can provide more information about these options.