Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 1-19)


15 OCTOBER 2007

  Q1 Chairman: Good afternoon everyone. Could I welcome you to this, the first formal evidence session of the science and technology select committee's investigation into scientific developments relating to the Abortion Act of 1967. Welcome to our first panel of witnesses this afternoon, to Professor Maria Fitzgerald, Professor of Developmental Neurobiology at UCL, Jane Fisher, director of Antenatal Results and Choices, Dr Kate Guthrie, the vice-president, Faculty of Sexual and Reproductive Healthcare, Professor Nail Marlow, the president of the British Association of Perinatal Medicine and last but by no means least Professor John Wyatt, professor of neonatal medicine at UCL. Welcome to you all and thank you very much indeed for coming at such brief notice. This is an inquiry which is specifically dealing with the scientific developments since 1967 and particularly since 1990 and the changes to the Human Fertilization & Embryology Act which came in as a result of amendments to that Act. We are strictly keeping to that regime so if we move off piste then I will stop very quickly and move us back on to issues to do with science and evidence. I will do exactly the same to my colleagues if they trespass across the dividing line. Professor Marlow, the Committee is hearing a lot about viability and clearly in terms of late termination the issue of viability is right at the heart of that. What do we mean by "viability"? What does the profession generally mean by "viability" and how would you define it?

  Professor Marlow: It is the capability of surviving the neonatal period and growing up into an adult. You would draw a distinction between viability which is the potential to survive and grow up into an adult human being and vitality which is signs of life at birth, which are two distinct things. When we talk about viability, we often think of a group of babies who are born at what we call border line viability and those babies are usually born before 26 or 25 weeks of gestation. At around 24 weeks of gestation, approximately half of babies will have the capacity to survive and be discharged home. That is usually the level at which we set our border line viability.

  Q2  Chairman: Dr Guthrie, in 1990 the legislation was changed making 24 weeks, if you like, the legal age of viability. Has anything changed?

  Dr Guthrie: In what respect? In terms of science and technology?

  Q3  Chairman: Yes.

  Dr Guthrie: My understanding from the literature is that it has not changed. Reading UK studies and studies which I have read about but are yet to be published, my understanding is that there have been no great advances. There have been advances in maybe looking at foetuses in the womb and we see more for example with ultrasound but in terms of viability and survival my understanding is that there has been no great advance.

  Q4  Chairman: In terms of Professor Marlow's definition of viability, you would accept that?

  Dr Guthrie: I would entirely.

  Q5  Chairman: What about you, Professor Fitzgerald?

  Professor Fitzgerald: That is not my area of expertise.

  Q6  Chairman: Professor Wyatt?

  Professor Wyatt: I would accept that definition of viability. It is the ability to survive and grow up into adult life with optimal medical care.

  Q7  Chairman: How do you stand on the 24 weeks? That is the legal definition at the moment. It was created in 1990 as a result of the change from 28 weeks to 24 weeks. Do you support that?

  Professor Wyatt: In terms of the scientific evidence, there have been advances in neonatal care obviously since 1990. There is evidence overall that neonatal survival has improved. There is a matter of controversy and debate about the evidence. It is important to differentiate between two types of study. There is a kind of study that involves the testing of the outcome of an entire population, often a geographically defined population, so all the pregnancies in an area are enrolled and the outcome of those pregnancies, including the babies born at the limits of viability, is then assessed. There are other kinds of studies based at single centres and often centres of excellence in order to see the level of care that is potential with optimal care.

  Q8  Chairman: If we take this issue of the very best centres of excellence, since 1990 or since 1967, are babies born at 23 weeks or 22 weeks more or less likely to survive than they were? Where is the evidence to support that?

  Professor Wyatt: There is a body of evidence published internationally showing that in tertiary centres of excellence survival has improved. Certainly since the 1960s there has been an incremental improvement in survival and that carries on into the 1990s.

  Q9  Chairman: Can I tie you down in terms of this incremental increase? What are we talking about in percentage terms, because there are very few babies that are born below 24 weeks, to be fair.

  Professor Wyatt: Indeed. What the evidence suggests is that there is also a very large difference in individual centres. This has also raised concerns, to know why it is, if you take one centre, the survival for instance of babies born at 23 weeks may be of the order of 20% or 25% and in another centre the survival of babies born at 23 weeks may be as high as 50 or 60%. That has been recorded.

  Q10  Dr Spink: Would this be as a result of clinical decisions to use steroids, for instance?

  Professor Wyatt: There are a number of factors obviously that one can speculate affect the chances of survival round these borders of viability. One factor is the level of expertise, staffing and resources that are available. Clearly, another factor I would suggest is the ethical attitudes of the staff and the parents that are taken towards babies around this gestation. There is evidence to suggest that some centres would have a more actively interventionist kind of approach and other centres might have a less interventionist approach to babies born around the limits of viability. It seems likely that this is one of the factors that influences the outcome. It has to be said it has not been systematically studied and therefore we do not know for certain what are these factors that cause a variability of outcome in different centres. The evidence does seem to be there in the literature that such variability does exist. It means therefore that quoting a single figure is not really very appropriate. There is quite a wide range that different centres have reported.

  Q11  Chairman: Jane, in terms of viability, are you in tune with the rest of the panel that say, "We are okay with the definition. We are just now arguing about whether it is 24 weeks or below that"?

  Jane Fisher: Yes. Again, it is not our area of expertise but certainly my experience is that what has been said so far is correct.

  Mrs Dorries: Professor Wyatt, on this area of studies, you made some comments in the national press on Sunday which were actually quite critical of one of the studies which has been undertaken. I want to ask you to what extent you thought that particular study should inform our discussion. I would like you to go into a bit more detail if you would as to why the survival rate of 23 week babies, particularly in your own unit, is so high. In your unit, there are as many as 42% of 23 week survivors, going up to 70% at 24 weeks. Why does your unit do so well compared to the study of units across the UK and do you think the study of the UK hospitals and survival rates should be informing this Committee?

  Q12  Chairman: Could you define what "survival" means?

  Professor Wyatt: Survival is slightly different in different studies.

  Q13  Chairman: What do you mean by it?

  Professor Wyatt: In the study that I was involved with, one particular study involved survival up to one year of age. If babies are going to die, the chances are they will die in the first few days of life, but there is a possibility of children surviving the first few months and then dying in later childhood.

  Q14  Chairman: It is up to one year.

  Professor Wyatt: One could take that as a definition. If my remarks were seen as critical of the study, they were certainly not intended to be critical of the scientific value or merit of the studies that have been performed to an extremely high, scientific standard. They are extremely valuable and I think they do inform us.

  Q15  Dr Harris: Including EPICure?

  Professor Wyatt: Including EPICure studies, yes. It is very important that this data is assessed by the Committee but I would argue, as I tried to, that there is a difference between a very large, population based study which effectively says on average across the UK this is what happens and the question of the possible outcome that may occur from individual centres.

  Q16  Chairman: Is that not what happens with all studies?

  Professor Wyatt: The design of the study depends on the question that you wish to answer.

  Q17  Chairman: I am not trying to be pedantic here. We are a Committee that is going to advise the government in this particular area. The government has to make policy across the country. It cannot make policy for an individual unit. That is the point I am making. Surely it is valid for the EPICure study to be across the country?

  Professor Wyatt: It is extremely helpful to see what is happening across the country but there is also a value in studies that say what is the outcome from specialist centres. For instance, if we were looking at something complete different like breast cancer, you would say, "What is the survival of breast cancer across the country?" but you might also be interested to say in a specialist centre, under those special circumstances, "What was the survival?" In other words, they both give you information.

  Chairman: I think it was important to tease that out.

  Q18  Mrs Dorries: Therefore, would we say that the viability of a baby born at 23 weeks depends into which unit or hospital that baby is born?

  Professor Wyatt: It must depend on a whole number of factors but one of those factors is both the staffing and level of resources that are available to that baby in terms of whether that baby is in a major centre. Some of the hospitals that the EPICure looked at did not have specialist resources for caring for very premature babies. It must also depend on the attitude of the staff and of the parents that are again in that particular unit. I would anticipate there are large variations. One of the other statistical in all these studies is that in any one centre one is dealing with very small numbers. Therefore, it is always possible that you have statistical effects which influence the outcome in individual centres. The value of very large studies such as EPICure is that by taking a very large number of babies you reduce the statistical error but, at the same time, you lose the information about differences between centres.

  Q19  Chairman: Surely the smaller the number the greater the statistical variation?

  Professor Wyatt: Exactly. That was the point I was making. If you have a very small number, you have a large, statistical error.

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