Reasonable requests should be considered, says Alison Lashwood

Every family’s experience of the genetic condition affecting them will be different.
A condition that does not result in death, but has an impact on quality of life, may be unacceptable for some, whilst others may cope with the implications. A 10 per cent risk of having a child with a genetic disorder is high for some, low for others. It will depend upon many factors, including support within the family, past experience of other family members with the condition, family dynamics, family size and the existence of affected children.

Different options
Each family usually considers alternative options. Many opt for prenatal diagnosis (PND – a test in an ongoing pregnancy). In some cases, couples will have opted for PND  because they would terminate an affected pregnancy. As the recurrence risk is the same in each pregnancy this may have occurred several times. For some couples, termination of pregnancy is not acceptable under any circumstances. For others, it may not be acceptable if they consider the risk of the genetic condition in their offspring not high enough to warrant termination.

PGD may be more acceptable to couples who are concerned about having a child with a genetic condition which has affected other family members, but where they feel the risk of the child developing the condition is not high enough to warrant PND and termination of pregnancy.

Risks and requirements
PGD is lengthy and complex. It has to be carried out in association with in-vitro fertilisation. The procedure carries risks for the woman: the frequency of multiple pregnancies is high and the impact of PGD on children born has yet to be fully evaluated. Most couples undertaking PGD are normally fertile and choose to compromise their chances of pregnancy as the success rate is only 20 per cent. The cost is high – between  £5000-9000 per cycle – and this cost is borne by the couple if no NHS funding is available.

It is essential that those families seeking PGD treatment have access to highly skilled professionals in well-established PGD centres. As clinicians working in those centres, we have a responsibility to ensure that couples requesting PGD are fully informed about the procedure, the alternative options and the potential difficulties, and to help them make an acceptable decision. When patients and professionals reach a consensus that PGD is the way forward, it offers something that no other technology can currently do.

Alison Lashwood is a Consultant Nurse in Genetics & PGD at Guy's and St Thomas' Hospital NHS Foundation Trust