Embryo Screening Or Designer Baby?
In the UK, pre-implantation genetic diagnosis, (PGD) is allowed to prevent a variety of serious inherited genetic conditions from being passed on to your baby. However, you can't have PGD to choose the sex of your baby, unless you risk passing on a serious sex-linked disorder such as haemophilia.
What Exactly Does PGD Involve?
In order to have PGD you need to have IVF treatment. The fertility clinic collects and fertilises your eggs and then lets them grow in the lab. After two or three days, when the embryos are ready to be transferred to your womb the embryologist tests them to see if any of embryos contain the genetic defect. Those that do are discarded, while any that are disease free can be transferred to your womb. If there is more than one suitable embryo, instead of risking the complications of a multiple pregnancy, you can have the other embryos frozen for future use.
What Conditions Are Covered?
The HFEA (Human Fertilisation & Embryology Authority) has a list of around 100 inherited genetic conditions that clinics can test. If you risk passing on a genetic disease that isn't on the HFEA list, you can ask the clinic if a test has become available for it. If there is one, the clinic can apply to the HFEA for approval for this disease to be added to the list of approved conditions.
Can I Go To Any Fertility Clinic?
No. In order to have PGD or PGS (pre-implantation genetic screening) you need to go to a clinic that has a licence from the HFEA to carry out PGD/ PGS. There are only a few clinics in the country that have the expertise to carry out this type of treatment. In the first instance, you need to discuss this with your GP and ask for a referral to a specialist.
I'm Not Sure It's The Right Thing To Do
Every situation is unique and though you have family members with a serious genetic disease it doesn't necessarily mean that you have inherited it yourself. The clinic will explain the implications of having genetic testing and the risks of IVF. The clinic will give you genetic counselling and advice to help you decide whether you should be tested yourself. If you prefer not to know your own status, you can have PGD on your embryos without being told if you are carrying the defective gene.
I Already Have One Sick Child
If you already have a child with certain inherited genetic disorders it is possible in some circumstances to have PGD to create what the HFEA call a 'saviour sibling'. This involves tissue typing the embryo (PPT -pre-implantation tissue typing) to see if there is a tissue match with your existing child. Then the clinic will make sure that the embryo is also free from the disease before implantation. When your new baby is born, the doctors can use the stem cells retrieved from the umbilical cord blood or bone marrow to treat and heal your sick child. This procedure is very tightly controlled by the HFEA and it decides each situation on an individual basis according to the welfare of the future child.
Isn't PGD Controversial?
Yes it is. Many people think that PGD is the 'slippery slope' that will lead to screening embryos for conditions that are not life threatening genetic disorders e.g. deafness, or depression, and could use it to create 'designer babies'.
A possible alternative to PGD is to encourage genetic testing prior to marriage to dissuade two people with the same genetic problem from marrying, concieving and passing on the defective gene, however this is highly unrealistic for two people in love.