Ellie Lee believes geneticists should stand up for 'directive' screening programmes that can help parents avoid having disabled babies
Genetic science passes the screen test
One of the best adverts for expanding our knowledge of human genetics is the progress being made in genetic testing and screening services offered to women, and sometimes couples, during pregnancy. Routine screening such as an ultrasound scan which turns up an abnormality may lead on to genetic testing. Families with a known risk of having a child with a particular genetic condition will commonly seek out antenatal genetic diagnosis. Other genetic tests are specifically targeted at those who are at the highest risk for other reasons - in the UK, for example, a test for Down's syndrome is now commonly offered to older pregnant women.
New genetic findings, and cheaper, more efficient and less invasive methods of testing are continually increasing the range of conditions for which screening is possible and feasible. But rather than celebrating this possibility, many people are worried; indeed, most commentators seem to accept that these inspiring developments are actually a problem, with troublesome and ethically sensitive implications.
One argument you hear is that, in offering women antenatal tests for fetal abnormality, and counselling them about the options if the tests reveal a problem, health professionals are directing women about what would be the best outcome of their pregnancy. As a result, it is said, services conflict with choice. The National Childbirth Trust has argued that the 'right of parents not to have antenatal testing is being undermined by heath professionals'. This concern was recently echoed by top medical journal the Lancet, which worried that 'women may feel pressured into undergoing prenatal diagnosis by physicians who feel that this is in their best interests'.
Another argument is that screening services encourage negative attitudes towards disabled people, if they are not in fact discriminatory. While only the most extreme critics of genetics would compare antenatal services directly with Nazi policies or old-style eugenic sterilisation programmes, many argue that the development and provision of these services is driven by aims which are in some ways similar. Ruth Hubbard, a feminist critic of antenatal screening, puts the case in her essay provocatively titled 'Abortion and Disability: Who Should and Who Should Not Inhabit the World?':
'I am...not drawing an analogy between what the Nazis did and what others in many of the industrialised countries are now doing. Because the circumstances are different, different things are being done and for different reasons. But a similar, eugenic, ideology underlies what happened then and the techniques now being developed.'
Once again, the Lancet echoes these concerns: 'where a problem has been detected in the fetus, what pressures are there on the couple to opt for termination and what does the acceptance of prenatal diagnosis say for our tolerance of "preventable" disability or disability per se?'
In response to these concerns, the professional community has adopted what is termed a 'non-directive' approach to advice-giving in the context of genetic testing and screening services. The goal, as recently defined by a publication of the UK geneticists' professional body, is not to offer advice on what to do following a test result, but to help 'adjustment to this knowledge'.
Uniquely in medicine, the traditional measures used to evaluate the success of services are rejected in relation to genetic testing and screening. A public health physician, for example, might think of using reduced birth incidence of the disease being tested for antenatally, or at the very least the uptake rate of the test offered, to measure the success of a programme. But for geneticist Angus Clarke, such measures are out of the question: 'when carrier screening programmes are judged by the uptake rate achieved and by the money "saved" by terminating pregnancies, rather than by the impact of screening programmes on those being offered the test, we will know that cost-benefit-based "public health genetics" (eugenics) has truly arrived.' As an alternative to the usual public health measures, geneticists offer the idea of restoring 'reproductive confidence' as a measure of success. By this they mean that couples at risk can make reproductive decisions 'confident in the knowledge that prenatal diagnosis offers them the possibility of healthy children'.
Geneticists are right to reject a crude public health, cost-centred, approach. However, their own perspective makes too many concessions to the critics of screening programmes, with the potential to cause more problems than solutions. A more combative response to criticisms would be more in line with the reality of people's expectations, as well as being a more fruitful way of promoting the further development of the service and the benefits of genetic science.
Consider first the question of choice. Contrary to what the National Childbirth Trust (NCT) and others argue, all the evidence suggests that patients welcome both the service and a 'directive' approach.
The NCT's own report on the subject produced last year counts against their claim that people are pressurised into testing. Only 10 per cent of women reported feeling pressurised and only one per cent refused the tests. What is more, evidence suggests that people like what is commonly called 'directive' advice. A recent research paper (S Michie et al, 'Nondirectiveness in Genetic Counselling: An Empirical Study', American Journal of Human Genetics, 60: 40-47, 1997) found that patients expressed satisfaction with the service even when different measures indicated they were being given 'directive' advice. Broadly, women want the service to be available because they want to avail themselves of the tests that are on offer, and they want geneticists to give them clear information, including such 'directive' information as the likely impact of having a child with a particular disorder.
Rather than restricting choice, a more aggressive promotion of the service in relation to certain important genetic disorders would significantly enhance choice. In the case of families with a known family history of a condition, it is the patients, not professionals, who are pushing for a more rigorous follow-up and the offer of testing to other family members. But some genetic disorders do not typically present themselves with a clear family history, and in these instances, geneticists could and should be playing a more active role.
Cystic fibrosis (CF) is a case in point. Approximately 1 in 25 of the population carries one defective gene for the condition. Fortunately, each of us has two copies of every gene (one from each parent), and so long as the other copy is normal we do not have the condition. What this means though is that many people are 'carriers' - in possession of one defective and one normally functioning gene - without knowing it. If two carriers have a child, there is a one in four chance that the child will be born with cystic fibrosis. Because of the probable absence of a clear family history, this is likely to come 'out of the blue'.
The fact that carriers are naive to the risk, and probably also to the reality of the condition, places an onus on professionals in such situations to play a particularly 'directive' role. In Scotland, but unfortunately not so much elsewhere, pregnant women and their partners are offered carrier testing for CF. If both test positive, the next step is to test the fetus with the option of termination if it carries both genes. The rationale for this is clear. As Mary Porteus, a geneticist in Edinburgh, put it to me: 'instinctively I am not a screener', but since CF is a serious condition 'that can totally change a family's life', raising the issue with people is a sensible measure to take.
What about 'choice' in all this? From a 'non-directive' perspective, the promotion of carrier screening is considered tricky. The fact that it is done during pregnancy, which ensures a high take-up rate, is considered highly problematic, akin to a public health, 'eugenics' approach. But from the perspective of the families it makes perfect sense. The couple who are screened did not freely consider the issue in advance for themselves, in that it was raised with them by health professionals. But it is surely clear that their choices in life have been widened, rather than restricted, by information that enabled them to avoid the birth of a child with a serious illness. Couples do not thank geneticists for dropping a bombshell on them if it turns out that the fetus is carrying the condition, but most are nevertheless glad that they found out.
Contrary to expectations then, a more 'directive' approach would widen choice. But what about the other reason for adopting a 'non-directive' approach, the need to protect genetic science from the accusation of 'eugenics', or of discriminating against disabled people? Once again, a more forceful response from geneticists would be more fruitful.
It is widely acknowledged that genetic services would not have developed if women did not on the whole choose to terminate affected pregnancies. As specialist Helen Statham puts it:
'it is unlikely that prenatal diagnosis would have been researched in the way it is, just to give parents reassurance, or, if most parents with an abnormality chose, to continue pregnancy. The "enormous potential for the avoidance of serious genetic disease and congenital abnormality" (Weatherall, 1992), can only be realised in most cases if women who conceive fetuses with such genetic diseases or malformations terminate the pregnancy.' (p157 Prenatal diagnosis: the human side, ed. Lenore Abramsky and Jean Chappel, 1994)
Yet this is a truth that dares hardly be spoken in public. Geneticists acknowledge that a consequence of genetic screening programmes may be a reduction in birth incidence of genetic diseases, but they forswear this as an aim. The report from the professional body for UK geneticists is clear on this: 'preventing transmission of genetic disease is not a primary aim of genetic counselling.' Professor Marcus Pembrey puts it like this: 'a reduction in birth incidence of a genetic disorder may be the consequence of genetic counselling and prenatal services, but it depends on what the parents choose to do.'
Of course nobody would want geneticists, or anybody else for that matter, telling women that they must terminate on receipt of a positive test result. Choice in this matter is most important. But in this instance, geneticists are to a degree hiding behind choice, with the unfortunate consequences that critical points are sometimes not rebutted, while a positive case for the broader benefits of genetics is hardly ever made.
Critics of genetic screening programmes conflate the desire for health, and hence an attitude which perceives living with a genetic disorder or disability as something best avoided, with negative attitudes towards disabled people. Wanting to prevent ill health in future generations is seen by critics to be the same as demeaning the lives of those who already suffer from genetic disorders or disability in the here and now. This is an unfortunate conflation; one which does not reflect the attitudes of parents or geneticists. In fact it is the opposite of the truth: supporters of genetic screening are anti-disability only in so far as they think it is better not to have disease. They believe that people living with a genetic disorder must be given equal rights, as people, and the resources they need to lead as full a life as possible.
These points should be obvious. That they are not accepted without question today is in part a consequence of the defensiveness associated with the 'non-directive' ethos. From this perspective, critics are rarely challenged, and the positive promise of genetics, its 'enormous potential for the avoidance of serious genetic disease and congenital abnormality', is rarely trumpeted, because it is (rightly but unfashionably) seen to embody a clear value judgement. As a result, genetic science and screening programmes continue to be dogged by the comparison with eugenics and the accusation of a bias against disabled people.
Individuals do and will continue to make choices faced with genetic risk. But a more 'directive', less defensive, approach from geneticists will increase those choices, and help foster a better understanding of the positive potential of genetic science.
Reproduced from LM issue 109, April 1998