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
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
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
Professor Wyatt: Survival is slightly
different in different studies.
Q13 Chairman: What do you mean by
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
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.