Select Committee on Science and Technology Minutes of Evidence

Examination of Witnesses (Questions 20-39)


15 OCTOBER 2007

  Q20  Dr Turner: Professor Wyatt, you talk simply in terms of survival, in terms of living or dying. Can you comment on the quality of life in terms of degree of disability given the large number of disabilities in preterm babies of this age? Do you have any views on the reasons why these babies are delivered preterm so early?

  Professor Wyatt: It is sadly true that babies born around the limits of viability have a high risk of having subsequent problems and these problems range from physical problems, neurological problems, learning difficulties, behavioural problems and so on. There is a large number of studies which have been performed and are currently being performed into the long term outcome. Again, the studies have quite a range of variations in outcome between different studies. They vary in the precise measures that are taken. To answer a question such as the quality of life is very difficult. It is clear that some babies born at the limits of viability tragically are profoundly disabled but the evidence suggests that severe, profound disability is actually relatively uncommon as a long term outcome. We do have quite a large number of children who have some learning difficulties, behavioural problems, but I would resist the suggestion that that means their life has no value or that it is not appropriate for us to care or to give these babies the very best chance of a good outcome.

  Q21  Dr Turner: Can you comment on the reasons for such early parturition? Do you think there is a limit between prospective disability and early delivery? In other words, a natural abortion, for want of a better word?

  Professor Wyatt: There has been a huge amount of research as to why babies are born very prematurely and we know that there are a large number of factors which increase the risk of prematurity, but it is true to say that in any group of premature babies a very significant proportion are those in which no reason can be identified as to why the mother went into labour very prematurely. It is not true to say that the presumption must be that there was a congenital problem with the developing baby in the womb, with the foetus, which was the cause of the prematurity. The research that goes on into the cause of injury suggests that in the majority of cases damage to the brain and the developing nervous system happens around the time of delivery, sometimes immediately before, sometimes during the delivery process, sometimes in the critical first few days of life, sometimes later on during intensive care. These are the issues which we are trying to address and many workers in the field are trying to address to minimise the damage that occurs to the brain around the time of delivery.

  Q22  Chairman: The thesis presented by Professor Wyatt appears to be that if you have a high quality specialist unit the chances of surviving below 23 weeks are significantly increased. Those were the words that were used: "significantly increased". That is what your article said.

  Professor Wyatt: To clarify, less than 24 weeks.

  Q23  Chairman: Sorry; less than 24 weeks. Is not 23 weeks less than 24 weeks?

  Professor Wyatt: Yes.

  Q24  Chairman: At 23 weeks. Have you picked that up in the EPICure study?

  Professor Marlow: Obviously the data are still being analysed at present.

  Q25  Chairman: I do not want you to reveal the data. Just give us the facts.

  Professor Marlow: In effect I can see no statistical improvement in survival at 23 weeks from the preliminary analysis we have had of the data.

  Q26  Chairman: Is that on individual units?

  Professor Marlow: We have not looked at those data yet. That is something that we will do some time down the line but we have not had a chance to analyse survival by unit. To my mind, there is no incompatibility between what I have said and what Professor Wyatt has said. In medicine we always need centres of excellence that are pushing boundaries back and are leading the way forward for many of us to follow often. It is very important that, if units have a philosophical agreement with starting care at very low gestations, they should try and provide the care to their ability. That is likely—and I think there is evidence from other countries—if followed through to produce improved survival. One of the problems is of course that the rates of disability at low gestations do rise quite steeply. Down at 25, 24 and 23 weeks we are certainly looking at about 25% of the population who will have serious, life long disabilities.

  Q27  Chris Mole: Professor Marlow, you obviously cannot reveal what is going to be in EPICure two but in terms of our inquiry which is scientific developments since 1990 primarily is the original EPICure study still relevant for people to take into consideration or is it becoming out of date?

  Professor Marlow: I think the survival rates are becoming out of date. If you look around the world at very low gestations, there is very little evidence that any of the rates of disability differ between different countries. We recently compared the outcome in a very low gestation in France to ourselves and the results are identical. I have also had the opportunity to look at data at North America. Again, when they are defined by gestation, the rates of disability are much the same. I am fairly confident about that. Nobody has shown really a significant improvement in that rate of disability over the last ten years. What we have seen, certainly in the Trent region of the UK, are significant trends in survival at 24 weeks but we have not seen those at 23 weeks. Even in an area which is dealing with 67,000 births, we see an almost twofold variation in survival at very low gestations, at 23 weeks for example, which reflects the small numbers of children. One extra child surviving one year pushes the figures right up. There is a lot of variability. It happens at very low gestations and survival is mainly related to the statistical confidence around what happens over one year.

  Q28  Chris Mole: Professors Marlow and Wyatt, are you of the opinion that there is any link between abortion and subsequent preterm births?

  Professor Marlow: Recurrent abortion is thought to be a risk factor for preterm births. I am not an expert in that area and I would not push that any further.

  Professor Wyatt: There is scientific evidence of a statistical association between a previous induced about and an increased risk of subsequent premature delivery. The problem with studies like this of course is that statistical associations do not in themselves prove a causal link and therefore there is a number of scientific and other questions that go on to try to tease out the question as to whether or not there is a genuine causal link or a statistical association. Having reviewed the evidence myself, my impression is that there is sufficient scientific evidence to suggest there is a causal association and a number of large studies that have been performed have suggested that there may be a causal link. That is, to me, the force of the evidence, such as it is.

  Q29  Chris Mole: Is there a variation in that between one induced abortion and multiple induced abortions and the impact on the risk of subsequent preterm birth?

  Professor Wyatt: Statistically the evidence, the majority of studies, appear to show that there is what is called in rather unpleasant terms a dose response relationship. If you have more than one induced abortion, it increases the risk of a preterm delivery in a subsequent pregnancy.

  Q30  Chris Mole: But one might not?

  Professor Wyatt: Statistically the majority of studies suggest that one probably does but there are matters of scientific controversy.

  Q31  Chairman: Professor Marlow, would you support that?

  Professor Marlow: I would not disagree.

  Q32  Chris Mole: Professor Wyatt, you have made some comments about an estimate of the cost of abortion and preterm births to society. How accurately can we put monetary terms on those sorts of issues?

  Professor Wyatt: I am not a health economist and these are very technical, complex areas. I would not in any sense wish to. It is a study which, as far as I am aware, has not been performed and, looking at the health economic aspects of a whole number of factors in terms of the provision of premature care, it is something that is important.

  Professor Marlow: Not all preterm delivery is at border line viability. The vast majority of preterm deliveries are at later gestations where survival is very high in most centres across the UK and the developed world.

  Q33  Chairman: Below 24 weeks there has to be a lot of intervention.

  Professor Marlow: No. When you say there is a risk of preterm birth, I would like to draw the distinction between there being a risk of birth before 36 weeks of gestation and birth before 24 weeks of gestation.

  Mrs Dorries: The definition of preterm is 36 weeks.

  Q34  Chris Mole: One of the technological developments that has happened over the last decade or so is the introduction of 4D images. Can I ask all of the panel if they believe there is anything we can learn from that that is relevant to this?

  Professor Fitzgerald: At the moment what we can learn is very limited simply because the technique is still under development and still really at a stage of trying to confirm that a lot of the structures that you see are similar to those seen in animals and other mammals, trying to identify the different areas, but I think it is a technique that in the future will probably be very useful for prediction of outcome if that was what you were asking, yes, but perhaps not so much at the moment.

  Q35  Chairman: Is that generally agreed?

  Professor Marlow: It is helpful in terms of prediction of abnormality and therefore one is able to see structures that one would not see in ordinary, two dimensional, real time, 3D ultrasound. I do not think it tells us any more about foetal development than we probably knew already.

  Dr Spink: Would the panel accept that 4D imaging has brought about or is starting to bring about a sea change in public attitude towards abortion since they can now see the child developing at 18 and 20 and 22 weeks in a way that they had not perceived before when they were thinking about foetuses rather than real children with real limbs, fingers and finger nails, forming a relationship with their mother, listening to their mother's voice, even at that stage? It has caused a change in public perception on the value of abortion to society.

  Q36  Chairman: There is a significant difference between what we mean by public perception and how we measure it but I am sure Dr Guthrie and Jane Fisher will answer that.

  Dr Guthrie: Certainly there is public debate. I am a clinician. My job I suppose is to interpret the science to the women that I see in the clinic. My women are certainly a lot more, shall we say, informed and they are asking a lot more questions than they used to do. That has not reduced the number of women seeking abortions. There is something about, yes, there is more knowledge or we think we have knowledge or we have clues. How do we interpret them? The fact remains that there is still a need out there for women to access services. Despite what women know, it is very interesting that the demand is still there.

  Jane Fisher: They do provide what are quite memorable images of a developing baby but what has muddied the waters is people thinking we can get more clinical information from those images and it is important to make that distinction. Yes, the images may be very beautiful but they are not necessarily adding any more to clinical information about developing babies.

  Q37  Chris Mole: On the question of foetal organ development, there is a lot that helps our understanding of the concept of viability in terms of the development of the nervous system, the capability of the lungs to function and so on at different ages. How much has our understanding of all that changed in the last 10 or 20 years?

  Professor Fitzgerald: In terms of 4D imaging, I do not think it has told us anything about the development of the nervous system. An image of a body tells you nothing about the nervous system. I think it is really important to separate the brain from all other organs. We really will be able to understand a lot about general organ function and dysfunction in foetal life but we still really have no knowledge of what the structural correlates of consciousness are. We simply do not know. That is incredibly important. We can guess a number of things about the development of the human brain at various stages of gestation but it really will be just guessing. All of our functional understanding of what infants may or may not be able to process by the brain have been performed after a baby is born, not in foetal life. That is an incredibly important point because the brain in a foetus is perfused effectively by sleep inducing chemicals. This is something that is not well understood. It is not possible to extrapolate back from a 23 or 24 week baby, which Professor Marlow and Professor Wyatt have been talking about, to how the nervous system will be functioning in utero as a foetus. It is in a completely different environment.

  Q38  Chairman: How do we know?

  Professor Fitzgerald: We know that from two important areas of study. One is from work on sheep foetuses and is by Professor David Mellor in Sydney, a huge body of work studying all of the hormones that are perfusing the brain in a foetal lamb and measuring brain activity over the whole gestation period. We know it as well from the work of Professor Lagercrantz at the Karolinska Institute who also measured equivalent hormones in human foetuses. There is very strong evidence that the foetus is effectively asleep. It is like you asking if a man who is deeply sedated feels the same as a man who is not. It is that kind of question.

  Q39  Mrs Dorries: There has been a more recent study, has there not, in the United States that shows perhaps the opposite of what you are saying? You said you are just guessing and you cannot say 100% that a foetus cannot feel and cannot respond to toxic stimuli or whatever. Therefore, if we do not know, is it not more humane and preferable that we come down on the side of the foetus and assume that the foetus can feel? I ask this for a very specific reason. I was present at two 4D screenings recently, one where a needle was inserted into the abdomen of the mother and the baby physically recoiled from the needle on the screening, and the other one where a baby was simply nudged and pressed in order to change position. The baby obviously was pulling faces and did not want to do it. Having witnessed both of those 4D screenings of both of those babies, one was very aware a needle was coming at it and the other was very aware that its position was being changed. If it was deeply asleep and unconscious, how was this foetus aware of what was going on in utero?

  Professor Fitzgerald: I think it is important that you understand the nature of the reflexes in an integrated nervous system. If, God forbid, you were a quadriplegic, you were somebody whose spinal cord had been damaged like Superman's[1] was. It was damaged at a very high level so you could feel nothing below the level of the lesion. You could not move and you could not feel anything. If I then put a needle in your toe, you would feel nothing but your whole body would recoil. The nervous system below the level of the brain is incredibly organised.

1   Note from the witness: Referring to the actor, Christopher Reeve, and campaigner for spinal cord injury research. Back

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