听Back to main page
BRITISH BROADCASTING CORPORATION
RADIO SCIENCE UNIT
CASE NOTES 7. - Premature Babies
RADIO 4
TUESDAY 25/01/05 2100-2130
PRESENTER:
MARK PORTER
CONTRIBUTORS:
Neil Marlow
DAWN ISAAC
ANDREW CURRAN
DIETER WOLKE
GORM GREISEN
PRODUCER:
GERALDINE FITZGERALD
NOT CHECKED AS BROADCAST
PORTER
Hello. Today's programme investigates the long term implications of prematurity - being born too early.
The normal gestation period for a human pregnancy is 40 weeks. Babies born before the 37th week of pregnancy - so three weeks or more before their due date - are regarded as premature. In most cases it makes little difference to them, but the outlook does vary depending on how far the pregnancy has progressed. A baby born at 35 weeks is unlikely to cause much concern, while fewer than half of those born at 25 weeks will survive, and most of those that do will be left with some form of long term disability.
I'll be finding out how one mother dealt with a growing sense of unease that all was not well with her youngest son.
CLIP
We were actually at a Christmas drinks party and Harvey wasn't due until the end of February, so I wasn't exactly expecting to have him there and then. But I went into labour at the party. I remember a consultant obstetrician going to my husband at the time and saying - Graham, I haven't done a home delivery in 10 years and I do not intend to another one here the wrong side of a bottle of wine, now will you please take her to hospital. So that was how he came into the world. And he spent the first couple of weeks of his life very much monitored and being looked after by the team in intensive care.
PORTER
And I'll be talking to a doctor from Denmark, where they have a much less aggressive approach to dealing with very premature babies - those born under 25 weeks are unlikely to be even considered alive, let alone transferred to a special care baby unit.
My guest today is Neil Marlow, professor of neonatal medicine at the University of Nottingham, and one of the authors of the EPICure study - a landmark piece of research looking at the long term outcomes for babies born very prematurely, under 26 weeks.
Neil, more of those results later, first let's cover some background. Why are one in ten babies born prematurely?
MARLOW
Well they're usually born for one or two reasons. One because they have to be born and therefore the pregnancy is shortened and that may be because the mother's ill, for example has problems with her blood pressure, commonly called preeclampsia.
PORTER
This is doctors intervening ...
MARLOW
That's doctors intervening yeah. And we sometimes have to intervene if babies are not growing very well before birth. And then the second group are effectively where the pregnancy decides it's time to deliver and either the membranes - the bag of waters around the baby - rupture and the woman goes into labour or just labour starts by itself.
PORTER
And are there particular groups that are more likely, particular women that are more likely to go into labour early?
MARLOW
If you've got a multiple pregnancy you're much more likely to go into early labour ...
PORTER
Twins and triplets.
MARLOW
If you've got triplets you deliver earlier, on average, than if you have twins for example. In addition there are some women who find it difficult to carry a baby to full term and they will have had pre-term babies before. And although the majority of women go on to full-term the next time a small group of them will continue to have pre-term babies.
PORTER
What sort of hazards does a premature baby face? Obviously we're designed to spend 40 weeks inside and coming out too early is not good for us.
MARLOW
One of the biggest problems the baby has immediately is actually keeping warm because the baby's born when it hasn't got quite the same mechanisms for actually keeping its temperature up as a full-term baby has. The more pre-term you get the more greater - the greater this problem is. And the earlier you are born the less likely it is that your lungs will actually be ready to support life. And as you go down in gestation, as you get delivered earlier and earlier, more and more babies require intervention with ventilators and lots of intensive care support.
PORTER
As a rough rule of thumb and I know each case varies tremendously but I mean if we're looking at a baby that's born 32-37 weeks they don't really have a lot of problems other than keeping warm and feeding do they.
MARLOW
Not at all and most of them actually can be managed on the postnatal wards with their mothers.
PORTER
But the group that you specialise in - the very premature - so we're looking at babies 26 weeks or less - I mean basically they all need some form of intervention don't they?
MARLOW
Yes, I mean babies who are under 26 weeks will inevitably require some sort of help and support with their breathing. This may be through an invasive way - by putting a breathing tube down into the lungs and helping inflate the babies' lungs or it may be just by providing them with some pressure support.
PORTER
And how long might a baby of that sort of gestation - 26 weeks - spend in an incubator and on a ventilator?
MARLOW
Well usually I will tell parents that they're going to need between five and six weeks intensive care, which is quite a long time to be sat in an intensive care unit.
PORTER
It's a difficult time for parents, isn't it, I mean you're bonding with a new child through a sort of plastic incubator, you can't really touch them, you can't ...
MARLOW
It's an awfully difficult time for parents because nobody chooses to have a baby very early and often the doctors are forced into a situation where they have to hasten the delivery or we're just faced with a child that's going to deliver and trying to support the parents through that is well known as a major problem for mums in terms of bonding. We do quite a lot to try and help parents through this, we're very good at encouraging parents to care for their babies in the incubator. And parents often become very good at providing many of the aspects of the nursing intensive care.
PORTER
Unfortunately the problems don't always stop when the parents get to take their new baby home. Cerebral palsy occurs when part of a baby's brain is damaged - symptoms and signs vary from child to child, but typically include muscle spasm, weakness, poor muscle control and difficulty walking and moving.
In nine out of ten cases the injury is thought to occur in the womb - how or why remains poorly understood - with much of the rest occurring during labour and childbirth. Whatever the cause, cerebral palsy is around four times more common in babies born prematurely and the risk increases the earlier a baby is born.
The damage generally follows a one-off injury and is non progressive - the closest equivalent in an adult might be a stroke. But although the brain damage is non progressive, the knock on effects do progress, at least at first. As the child's brain grows and he or she develops then their problems often become more evident.
Dawn Isaac, a GP in Gloucestershire, gave birth to her son Harvey eight weeks early.
ISAAC
Of course he's a completely normal baby when he came home. And I also knew, as a medic, that we always compensate for time, so I kept allowing for the fact that he was a little bit late to smile and he was a bit late sitting up. And deep down actually I knew and it got to his second birthday and he still wasn't walking and I remember the paediatrician sort of saying look we need to assess him properly. She spent a couple of hours with me at home going through various things and after a while I just - I remember just looking at her and I said you're just going to tell me he's diplegic, aren't you, which basically is the mildest form, if you like, of cerebral palsy. And she said you know and I said - yeah of course I know. But I'd spent two years sort of "not knowing" in inverted commas because I didn't want to know.
CURRAN
The earliest that people reckon you can clearly identify cerebral palsy would be four or five months of age.
PORTER
Andrew Curran is a consultant paediatric neurologist at the Alder Hey Children's Hospital in Liverpool.
CURRAN
It's a very variable feast and it'll depend how severely you're affected as an individual, the more severely affected the more likely it is you'll be picked up earlier. Sometimes it can be very, very subtle and you may not be picked up until you're four or five years of age. Cerebral Palsy is a disease that can affect any part of the brain and therefore there can be physical, mental and emotional problems following cerebral palsy. Physical ones, if you've got those, are predominantly to do with increased, what's called, tone in the muscles of the body and in that instance you can't relax or contract your muscles normally and even though they're stiffer they're inclined to be weaker than normal muscles. Intellectually you can have everything from a specific learning disability to do with reading or maths or something of that nature, right through to severe intellectual problems where your - that whole part of your brain doesn't work properly at all. And emotionally there's a tendency for them to be emotionally younger than their years.
ISAAC
When he was about two my husband took him to pick up our eldest son from a football party and he said - I can't play football can I dad? So Graham said - No you can't Harvey. And he said - That's because I can't walk isn't it dad? At that stage he wasn't standing or anything. And Graham said well yeah that's right. He said - So when will I walk then dad? And out of the top of his head - we'd always been told that he would probably walk about four. So Graham said - When you're four. On his fourth birthday he said to me - Am I four today mum? So I said - Yes darling, happy birthday, you're four today. And he said - You said I'd walk when I was four. Oh I tell you that just wrenched me in two. So literally two weeks after his fourth birthday I came in from evening surgery and he said - Look at this mum. And he stood up and he took about 10 steps across the kitchen floor and I mean I was blown away. So that's when he first took his steps. They were very tentative, he used to fall over an awful lot. But gradually he got better and better and he would walk with like a little zimmer frame on wheels and he used to zoom around on that and then get it whizzing and then push himself up and sit on the back of it and skid down the lane, he used to terrify me. But then he started to go downhill again as his leg got more and more twisted and that's when really we were faced with the surgery. Just before the operation, when we were talking to a specialist, he was walking with his right foot right up on tiptoes, almost walking on the top of his foot and facing backwards, it really was very twisted. And I remember talking to the consultant who said quite frankly he didn't really think we had a decision to make in that if we did nothing he would end up in a wheelchair by the end of the year because that walking pattern just wasn't sustainable.
CURRAN
As far as treatment's concerned you've got to look at the whole human being, who is this human, what are their strengths and weaknesses, what do you need to support them with? For the legs themselves the treatment is physiotherapy and that's aimed at really three things. First of all to make sure that muscles don't become excessively shortened and stuck in a shortened position and that's called a fixed contracture, that's done through various exercises to promote muscle length. Secondly, we use splinting where we use things, particularly at night, to hold the legs in a relaxed neutral position so the muscles don't get the opportunity when the child's asleep to pull short and then get stuck in that position. And thirdly then we have a lot of interventions such as botulinum toxin injections into the muscles to help them relax. Surgery is often - when you get to the point of fixed contractors that is a time when surgical intervention is your only way forward really to achieve normal positions in the joints, i.e. where a foot isn't being forced towards the floor or a knee isn't being forced backwards so that the knee is permanently bent. And I think for me the most important thing is really who is this individual, human being, how can we help them be happy and have good self-confidence? And if you're doing that in truth you're doing the most important thing for that person.
ISAAC
He had his operation in July and we were told that he wouldn't walk for a year. I'm going to do proud mum for a minute now because we are now six months post-operative and he is walking with crutches. And in fact just after the operation he turned to me and I was explaining about how long it was going to be and why it was necessary to have the operation because it's quite hard to take that on board when you're only seven and he said - Don't worry mum, no don't worry - he said - because they're wrong. I said - What do you mean they're wrong sweetheart? He said - I won't be a year, I think it'll be three months. Anyway bless him it's not three months it's six months but he's walking with crutches. And the hope is that he will continue to improve, we have to do exercises every day with him, he goes to physiotherapy every week. The concern will be that he may, as he goes through his adolescent growth spurt, there is always a possibility that he might need more surgery but I mean we cross that bridge when we come to it really.
PORTER
Dr Dawn Isaac talking about her son Harvey.
You're listening to Case Notes, I'm Dr Mark Porter and I am discussing the long term effects of being born too early with my guest Professor Neil Marlow.
Neil, now you're following a group of very premature babies to see how well they do - that's the EPICure study - what have you learnt so far?
MARLOW
Well it's been a very important group of children for us to follow-up. We recognised in 1995 that we knew very little about the outcome for these children and we've been trying to study that ever since.
PORTER
And we've been doing a lot more to them haven't we, we're saving a lot more children.
MARLOW
We've been doing much more in terms of intensive care and in fact even since we published our first results I think survival has improved quite dramatically. But these are a group of children who need a long time in intensive care and in fact of the 1200 or so babies that were born alive only 300 of them went home and of those that went home they had signs that they were likely to develop problems - they had abnormal brain scans etc.
PORTER
So these are 300 babies that you've been following.
MARLOW
Three hundred babies that we've followed up. And we went to see them at two and a half and roughly speaking at two and a half a quarter of them had what we term severe disabilities. About half of them had no disabilities and the other quarter had sort of minor disabilities if you like.
PORTER
Of the group that had severe disabilities what sort of things are we talking about?
MARLOW
Well we're talking there about things like cerebral palsy and severe developmental delay, we're talking about blindness and deafness. So these are important disabilities. It was very important for us, however, to learn about what this meant for them as they got older because assessing a toddler, as anyone knows, is actually quite difficult and knowing that that's going to predict what they're going to be like at six is difficult. So we went to see them when they were at school age and ...
PORTER
Which you've just reported on.
MARLOW
... which we've just done - and we again threw up some interesting findings here. If we concentrate first on the physical disabilities - if you remember I said that about one in five had cerebral palsy, we still had roughly the same number that we would class with cerebral palsy, i.e. when we examined the child there were signs, but actually the degree of disability in that group was not high and in fact half of those children didn't have significant disabilities with that. Now this is a very important finding for us because it means that actually some of these things that seemed to be bad early on can actually get better as time goes on.
PORTER
Or become less significant to the child.
MARLOW
Or become less significant to the child, that's right. And we also had - we were also reassured to know that we had - despite - there was a lot of eye problems as new born babies, very few of these children in fact were severely blind and very few of them were profoundly deaf.
PORTER
From a purely physical point of view how many of them would you regard as "normal" in inverted commas?
MARLOW
From a physical point of view we're looking at about 80% of them being normal.
PORTER
Which is pretty reassuring isn't it.
MARLOW
It's pretty reassuring. I mean in that I'm including people like myself who wear glasses.
PORTER
So far we've concentrated on the physical consequences of being born too early but what about the more subtle effects on brain function, how does prematurity influence higher brain functions responsible for cognitive ability - things like intelligence and skills like reading and communication? Dieter Wolke is visiting professor of lifespan psychology at Bristol, and a member of the EPICure study group. I caught up with him in our studio in Geneva, and started by asking how the premature children in the study compared to their peers in the classroom.
WOLKE
The major finding that we had regarding their general cognitive abilities was that 41% of the children in the extremely pre-term group had scores two standard deviations below the mean, which usually means that they need some special support, in comparison to less than 2% in the control group of full-term children.
PORTER
So what sort of difference in IQ are we talking about in terms of points?
WOLKE
They're more than 30 points below the children you would expect in a normal population.
PORTER
That's a pretty significant - I mean that's a large difference isn't it, what impact is that likely to have on a child at the age of six in terms of ability to go through normal education?
WOLKE
Yeah well we also did additional assessments on language abilities and we found that it clearly affects their language ability, it will affect their reading and it is most likely to affect also their maths skills in school. So it will actually in real life terms have a major impact of how fast they learn and what they can achieve at that age.
PORTER
Of course the other thing this is not a static problem - we're taking a snapshot at them at the age of six - one presumes that if they've got that sort of deficit that that might even become more significant by the time they're 13 or 14. Are there plans to follow them on further?
WOLKE
Yes there are definite plans and we have actually applied to the Medical Research Council to follow them up again at 10-11 years of age, which is a critical age period at the time of transition to secondary school. So at that time we will even be better to assess their cognitive abilities because they have been more clearly formed. There is also an indication that the problems may become worse because we compared them to previous data at two and a half years of age, I mean the same children assessed, and we find that their cognitive abilities have actually deteriorated, mainly because we presumably can measure them better.
PORTER
Presumably also there's a bit of gap widening going on, I mean the children who are born at term are pulling ahead, is that the case?
WOLKE
Well we have got some indication that the gap is widening, it's not that the full-term children are pulling ahead, it may be that the gap is widening because the extremely pre-term babies are dropping off and particularly in an ability which we call simultaneous information processing. Simultaneous information processing means like if you lay a puzzle you have to know the piece you have to set, you have to know the whole picture, you need to know the colour, you have to process all of this information together. And in these particular information processing skills we find that extremely pre-term babies have got major problems which affects quite a lot of areas of cognitive functioning.
PORTER
This is a worrying finding, particularly for parents, a lot of babies in the UK are born premature, not many are born at this level of prematurity, do we know - is there a cut off after which being born premature is unlikely to have a significant impact on your cognitive ability, do we know that from previous data?
WOLKE
Well we looked at previous data, we have carried out studies both in Britain but also in Germany, an epidemiological study, it means a whole population study. And what we detected there is that really if you're born premature and down to about 32 weeks gestation, that's up to eight weeks before term, the effects are very small, long term, looking at six, eight or 12 years of age. However, if you get into the smaller area of being born very pre-term, and in particular extremely pre-term, then you find that the effects every week you lose have got more massive effects, at that time we calculated about three IQ points.
PORTER
What's the impact going to be on assessment of premature children and education, is there anything we can do or we should be doing to intervene at an earlier stage that might try and close this gap between very premature children and their peers?
WOLKE
It's very important to say that this particular study - EPICure - is looking at extremely pre-term babies who are at the limits of viability and didn't survive - most of them didn't survive 20 or 30 years ago. But there are a number of implications. We can look at it whether the bottle is half full or is half empty to make decisions in neonatology. The second thing is that the major focus currently of looking after these children once they're discharged is to identify those who have got the major problems. However, it would be important to really follow-up also in the normal care all families because the major impact of making changes would be to detect those children who have got only minor problems and support them early on. The third thing is that we often have got assessments which are carried out by either paediatricians or in general practice which are focussing on their motor disabilities. However, the major problem that we detect is learning difficulties and we also know, but this data hasn't been published, maybe also in the behavioural domain, in particular attention deficit problems.
PORTER
Dieter Wolke.
Denmark has come up with a radical, and somewhat controversial approach to dealing with very premature babies. After widespread consultation in 1990 it was decided to take a less interventionist approach to dealing with those babies born very early. As a result few babies born before 25 weeks are even considered to be alive at birth, and the decision to resuscitate and offer life support is a joint one taken by parents and attending health professionals. Dr Gorm Greisen is a professor of paediatrics in Copenhagen.
GREISEN
I mean the first decision to be taken actually is whether to consider this baby alive or not alive at birth. So we do not routinely try to resuscitate any baby. The second decision to be taken is whether a baby, very tiny baby, should be taken out of the labour ward or the room and to a neonatal intensive care unit or it should better be left with its parents. And there for instance we're trying a practice - it's not always successful - but we're trying a practice where we bring an incubator, we bring a doctor, a nurse, and then they will do the first care for the baby within the room where the mother has given birth to allow more time and that allows, you could say, a more gradual decision of whether to proceed with more life support or whether to abstain.
PORTER
So this minimally invasive approach, which is basically almost a wait and see for the first few minutes or maybe half an hour or so ...
GREISEN
Or hours or days.
PORTER
But that's a crucial time, isn't it, I mean if you've got a very young baby my concern I suppose would be, as a practising clinician, that the baby that does well anyway might have done even better had he or she been offered a little bit more support in those first few hours.
GREISEN
That is a very important question and I think there's no good answer, no complete, no universal answer to it. In our experience many of these babies are not compromised at birth, they're just very immature and they do very well with little breathing for some minutes. And the point is that if you let them do that you see that they are much more competent than you thought. For instance in our national cohort we have the 54 survivors less than 26 weeks and of those less than half were ever mechanically ventilated. So more than half actually breathed on their own all the way through. And as far as I know that very rarely happens in Britain and the United States because practitioners now are so keen not to miss the moment, you could say. So this is the benefit. But there's no question to me that there's sometimes also a problem that you get in too late.
PORTER
What about the parents in all of this, many of them must say I don't care I want you to do everything for my child, he's my child, please doctor do something.
GREISEN
Yes, parents differ a lot to my experience. I mean some will clearly for emotional and rational reasons ask everything possible to be done and accept sort of great suffering. Others though will not necessarily. I mean there may be parents who already had children and to whom an extremely pre-term child is also a threat to their family life. So parents differ a lot. And secondly I say it's also a professional judgement as what we in principle do is to give appropriate support, I mean not proactive, not preventive, but just in time. The professional problem obviously is to be sure that you do that.
PORTER
And I suppose my last question would be how are you sure that that's happening because there are no firm and hard and fast rules and I can understand to some extent why, but how do you know what your other colleagues are doing, how do you know that someone is applying those guidelines properly?
GREISEN
Two reasons, one is one of statistics, I mean our data from the cohort, which I briefly mentioned, where we studied all survivors in Denmark for a two year period, actually contemporary with the EPICure study. We had 54 survivors of this and we had a survival rate of about 50% and 50% of the survivors would do without mechanical ventilation. When we saw on the outcome at five years of age and measured their IQ and looked at neurological and sensory problems the results actually appeared to be slightly better than those of the EPICure study. In the EPICure study only 20% were without any disability, whereas in our group this was 50%. I mean numbers are small, many conditions are different, so one should certainly not make a direct comparison. But still I think that this gives room for thinking that there might be a possible [indistinct word] going this way.
PORTER
Professor Gorm Griesen speaking to me from Denmark.
Neil, I am not sure Gorm answered me fully there - he suggests that his follow-up shows that the Danish approach is associated with fewer long term problems but part of that has got to be because fewer babies survive. I think I'd find it very difficult to walk away from a baby that was 25 weeks old because I automatically assumed it's dead without even trying to resuscitate it.
MARLOW
I think it is really difficult and one of the things one has to admire in Holland and Denmark is the fact they've had this social discussion as to what they should do.
PORTER
And in 1990, that's nearly - what 15 years ago.
MARLOW
Fifteen years ago now. As usual we're getting round to it and one of the initiatives I'm involved with is a working group from the Nuffield Council for Bioethics who in the next few months will be issuing a discussion paper and I hope that this will be discussed widely and openly and we can get good feedback, so that we can actually come up with some guidance for professionals. Perhaps belatedly but actually it's appropriate for our own very different multicultural society.
PORTER
And we are very interventionist here and do you think that your findings from EPICure suggest that we should alter our current practice in any way - are we harming children by being over-interventionist?
MARLOW
I think - I don't think it's just EPICure that tells us that. Over the past 10-15 years we've actually been doing much less, we're ventilating much less aggressively, we're using less interventionist techniques all the time. And we've also learnt over the last 10-15 years the value of really good nutrition. And one of the important reasons that we would like to do EPICure again in 2005, 2006 is that actually we do want to see whether what we've done has brought those improvements.
PORTER
Neil, I'm going to have to stop you there, we're out of time. Professor Neil Marlow thank you very much.
Next week's programme is about joint replacement and includes a report on how hip resurfacing - an alternative to replacement often used in younger more active arthritis sufferers - has transformed the life of one the nation's favourite cooks. That's assuming I can get a word in edgeways.
ENDS
Back to main page
|
听Print this page
