A baby after Rb
Having a baby after retinoblastoma
Planning for a family can pose additional challenges for people affected by retinoblastoma. We take a look at the considerations involved and the options available.
If you had retinoblastoma as a child, you may have an increased chance of having a child with retinoblastoma. The chances of a child being affected can vary from no greater than the general population to 50%. It is important to know whether you had unilateral or bilateral Rb. Genetic testing may also be helpful.
It is sensible for anyone who has had retinoblastoma to see a geneticist before they plan a family, to discuss what tests have been performed and to clarify what their chances of having a child with retinoblastoma will be. This also gives the chance to have test performed before a pregnancy – the tests can take several months to get a result.
No right or wrong choice
Couples will then make their decision based on different factors such as the chances of having a child with retinoblastoma, the type of treatment that is now available, their own experience of the condition and whether they have other children. These decisions are very personal and there is no right or wrong choice. In addition, a couple’s choice may change with time or their circumstances.
In general, the choices fall into three groups:
Deciding to have a child without any testing in pregnancy
All children of a parent who has had retinoblastoma should be regarded as being at risk of developing retinoblastoma and should have regular eye checks under anaesthetic, unless genetic testing reduces the baby’s chances of developing retinoblastoma to population levels.
If doctors have obtained results that mean they can offer an accurate test to a baby then they arrange for a blood sample to be taken from the umbilical cord when the baby is delivered. The testing can then be done quickly so that the results take less than two weeks.
We suggest that all babies in this situation have a provisional appointment made for an eye check, so that if there is a delay in getting the results, then there is no delay in checking the baby.
If the results show that the baby does not need eye checks then we can cancel that appointment. The appointment for the first eye check would be made at two or four weeks of age, depending on the family history.
Testing for retinoblastoma in pregnancy
Testing in a pregnancy for retinoblastoma can only be done if genetic testing has previously been carried out in the family, and the results mean that a test in pregnancy would be possible.
This is usually if a parent has the genetic form of retinoblastoma. Tests in pregnancy can be done in two ways, either by chorionic villus sampling at 11 weeks of pregnancy or by amniocentesis at 16 weeks of pregnancy.
Both tests carry a small risk of causing a miscarriage so it is generally recommended that these tests are only done if a couple feel sure that they would not want to continue a pregnancy if the baby would have a high risk of developing retinoblastoma.
Anyone considering this should be seen by a geneticist before they plan a pregnancy so that the necessary background laboratory work can be done.
Pre-implantation genetic diagnosis (PGD)
This technique is available in only a few centres in the UK – not all of those centres offer testing for Rb. Ask your GP to refer you to your local service.
In brief, it is a combination of IVF (fertility) treatment and genetic testing. IVF is used to create embryos and these embryos undergo genetic testing at a very early stage. Unaffected embryos are then used to try to achieve a pregnancy.
PGD has obvious advantages over testing in pregnancy in that it does not involve a termination of the pregnancy. However, several months of background work are needed before the procedure can be done. It will not be possible for every couple and the success rate (ie babies born after the procedure) is around 30% for each attempt.
This is an option considered by some couples, who may have difficulties in getting pregnant or who feel that they do not want to have a child with retinoblastoma, but would not want to have a termination of pregnancy for the condition. It is a useful option but is not an easy process to go through.
It is expensive, costing around £9,000 for each cycle. Some trusts will fund it on the NHS, others are more reluctant. Getting NHS funding usually takes several months and usually only one or two attempts will be funded. Funding is only offered to couples who do not have any unaffected children.
In summary, most people who have had retinoblastoma have an increased chance of having a child with retinoblastoma, compared to the general population.
There are different options available to ensure that a child is given the best treatment. Choosing the right option is a very personal decision. Anyone who has had retinoblastoma and who is thinking of having a baby should be seen by a geneticist to discuss the chances that a child would have retinoblastoma, arrange genetic testing and decide what options are best for them.
If you have any questions relating to issues covered on this page please call one of our support workers on 020 7377 5578 or email email@example.com
This article was written by Dr Elisabeth Rosser, consultant geneticist at Barts NHS Trust, for the Spring 2015 edition of the Childhood Eye Cancer Trust newsletter InFocus. Many thanks to Dr Rosser for her assistance with this article.