10

Preterm Birth Committee

Corrected oral evidence: Preterm birth

Monday 11 March 2024

3.10 pm

Watch the meeting

Members present: Lord Patel (The Chair); Baroness Blackstone; Baroness Cumberlege; Lord Hampton; Baroness Hughes of Stretford; Baroness Owen of Alderley Edge; Baroness Seccombe; Baroness Watkins of Tavistock; Lord Winston; Baroness Wyld.

Evidence Session No. 8              Heard in Public              Questions 106 - 121

Witnesses

I: Professor Stavros Petrou, Professor of Health Economics, Nuffield Department of Primary Care Health Sciences, University of Oxford; Professor Elaine Boyle, Professor of Neonatal Medicine and LCFC Professor in Child Health, University of Leicester.

Examination of witnesses

Professor Stavros Petrou and Professor Elaine Boyle.

Q106       The Chair: Good afternoon. Welcome, and thank you for coming today to help us with this inquiry. Your evidence and what you tell us will be important for us, particularly on the costs as they relate to preterm births. You are now online and on parliamentary television for whoever in the whole world might have an interest in this. Before we move on to the questions, I would be grateful if you could introduce yourselves for the record and say what your position is, et cetera.

Professor Stavros Petrou: I am academic research lead in health economics and professor of health economics in the Nuffield Department of Primary Care Health Sciences at the University of Oxford.

Professor Elaine Boyle: I am professor of neonatal medicine and child health at the University of Leicester, and an honorary consultant neonatologist at University Hospitals of Leicester.

The Chair: Thank you. We will move on to the questions straightaway. My colleagues might have a direct question and some of us may have supplementary questions. Timing is crucial for us today, so we will try to keep our questions short. Please can you try to summarise your answers succinctly, if you can? Baroness Watkins has the first question.

Q107       Baroness Watkins of Tavistock: We are obviously interested in the long-term impacts of preterm birth for babies and children, and indeed in later life. Can you discuss with us how preterm birth impacts children's neurodevelopment and educational attainment. Also, do you think there is evidence for long-term health, certainly through childhood, and to what extent that continues on into adulthood?

Professor Elaine Boyle: Thank you for that question. There is a lot to say. First, the impacts on child development, child health and, as you have said, education of being born at a gestational age that is before full term are wide-ranging. In general, the most immature babies have the worst outcomes. The sorts of outcomes that I am talking about are cerebral palsy, so problems with movement and posture, cognitive impairment, hearing and vision problems, problems with attention, health problems and socio-emotional problems.

So these babies, children and older individuals can face a wide range of problems, and they can be affected by one or more of these problems and more or less severely. Most of the information we have is from longitudinal cohort studies and retrospective studies, but it is important to think about the complexity of measuring these outcomes. The studies that we have used different measures to look at groupings by gestational age of the infants; of course, all cohort studies are subject to a degree of loss to follow-up. All those things make it a little more complex.

The other thing making it more complex is that we are now seeing that the impact of gestational age at birth is not simply a dichotomy between preterm birth and term birth. I know the committee has heard previous witnesses refer to this, but when considering long-term outcomes it is important to consider that it is probably no longer appropriate to talk of term and preterm birth in the same way as we have been used to doing. We are regarding gestational age at birth as much more of a continuum or spectrum, whereby the most immature children have the most severe problems, but there are measurable adverse effects of being born before full term—by full term, I mean between 39 and 41 weeks of gestation—even right up to 37 to 38 weeks, which we previously regarded as term.

Baroness Watkins of Tavistock: We might have heard about the 37 to 38 weeks; I do not remember. Is that all done on retrospective data?

Professor Elaine Boyle: Not all, no, but much of it is. Gestational age terminology has evolved in the last 10 to 20 years. It is fair to say that it has been somewhat confused and unclear until relatively recently. We now have a clear categorisation of different stages of the gestational age spectrum, which most people in the field are now starting to use. It stretches from the extremely preterm babies, at less than 28 weeks, and the very preterm, at 32 weeks and below, to the moderately preterm group of 32 to 33 weeks and late preterm of 34 to 36 weeks. Indeed, we have now started sub-categorising term birth, so that the 37 to 38-week group that I just mentioned would be regarded as early-term birth, and full term would now be classed as 39 to 41 weeks. As I say, we are regarding it much more as a continuum, and the more recent studies are starting to look across the whole gestational age spectrum.

Q108       Baroness Watkins of Tavistock: You talked about cerebral palsy, but there has also reportedly been a large increase in ADHD, dyslexia and dyspraxia. Does the data show that that tends to be later preterm, as it were: 34 weeks and beyond?

Professor Elaine Boyle: I am not a developmental psychologist. I know that you will hear from my colleague, Professor Johnson, in the next session, so you may hear more about that issue later. All these things are seen in relation to preterm birth. The outcomes in terms of autistic spectrum disorder, ADHD and those sorts of things in the late preterm and early term groups are much less clear, because the data is not there. Cerebral palsy is declining, thankfully, but it tends to be the province of the very preterm group. The more immature babies tend to have those sorts of developmental problems.

Q109       Baroness Watkins of Tavistock: From an economic perspective, we have just heard—the Academy of Medical Sciences published a report saying this—that we need to invest in children much more for the public pound, although the report is more flexed than that. Can you comment, obviously based on your research, on whether, economically speaking, we could delay most of these babies’ births by a few weeks?

Professor Stavros Petrou: A number of different studies have estimated the economic consequences and costs associated with preterm birth. The first thing to highlight is that they differ in a number of methodological respects. They differ in their perspective and in the types of cost that are included in their estimations—whether they focus on healthcare costs, the costs to the public sector, the costs to parents and families or the broader societal costs.

They also differ in a number of other respects, such as the time horizon that they follow—whether they focus on the short-term costs, the costs during the initial hospital admission or the costs during the first few years of life and throughout childhood. To a lesser extent, there have been some estimates of lifetime costs as well.

They also differ in the denominators they use in their calculus—for example, whether the denominators are restricted to survivors or cover all live births. Their costing methodologies all differ too.

Baroness Watkins of Tavistock: Another of my colleagues will ask a third question on this in more detail. In summary, you are saying, I think, that the long-term impact of preterm birth means that there are long-term economic challenges associated with it. Is that fair?

Professor Stavros Petrou: Absolutely. Tying together the two questions that you have asked, we have conducted a number of studies that have estimated the longer-term economic consequences of preterm birth. One study that I wish to highlight used decision analytic modelling to pull together evidence from various primary and secondary sources to estimate the public sector costs associated with preterm birth throughout childhood. It estimated the childhood cost for an annual cohort of children born in England and Wales at around £4.5 billion, in current prices. We also modelled the effects of a hypothetical intervention that would delay preterm birth by a week across the gestational ages. It estimated the potential cost savings, if there was a hypothetical intervention, at approximately £1.5 billion.[1]

Baroness Watkins of Tavistock: Per child?

Professor Stavros Petrou: No, to the public sector. £1.5 billion per year.

Baroness Watkins of Tavistock: Oh, billion. Sorry, I thought you said million. That is why I asked whether it was per child. Thank you.

Q110       Baroness Seccombe: It is a pleasure to have you here. Thank you for coming. My question is more about the immediate and long-term costs for the NHS, education providers and public services. Can you break those down and give us more information? That would be helpful.

Professor Stavros Petrou: The modelling study that I just referred to estimated the public sector costs to the NHS, social care services and education services throughout childhood for an annual cohort of children born at different gestational ages. The bulk of the incremental costs associated with preterm birth would be borne by neonatal services, so they would accrue during the initial hospitalisation. Nevertheless, other studies that we have conducted have focused on the longer-term costs associated with preterm birth based on the EPICure studies—EPICure 1 and EPICure 2—which followed up cohorts of extremely preterm children and control groups born at term.

The most recent study based on EPICure 2 that we conducted, which estimated the costs during the 11th year of life, found that the costs associated with special educational needs dwarfed health service costs during that year of life. So the general trends are that, overall, the bulk of the costs are likely to be felt during the initial hospitalisation, but by mid-childhood with each additional year of survival the proportion of the additional costs borne by education services outweighs the proportion of the costs borne by healthcare services.

Q111       Baroness Seccombe: How do these costs vary by the gestational age at birth? Is it just a slight change or is it considerable?

Professor Stavros Petrou: There are considerable differences. The first modelling study that I mentioned, which estimated public sector costs during the first 18 years of life, found that there was an additional cost associated with being born preterm of around £38,000 at current prices, but if you focused on extremely preterm children, the additional cost associated with them was more than £130,000.[2]

Q112       Baroness Seccombe: How do these costs compare with those for other health conditions?

Professor Stavros Petrou: There is no single study that estimates the costs of illness associated with all childhood conditions. No study has attempted to do that. It is worth bearing in mind that a number of methodological factors would restrict those types of cost estimations being conducted. There are certainly studies that have estimated the costs associated with specific childhood conditions that are published in the literature, but they differ from most of our studies in a number of respects and in the methods that they adopted, such as the approach to estimating costs, the study perspective and the period of follow-up that they focused on.

A recent systematic review of economic studies estimated the additional cost associated with childhood excess weight, both overweight status and obesity, at around $4,000 in the US. In comparative terms, those costs are lower than what we have found for very preterm birth and extremely preterm birth, but those sorts of cost comparisons have to be couched with all the caveats that I mentioned.

Baroness Seccombe: Professor Boyle, would you like to add anything at this stage?

Professor Elaine Boyle: I would just flag that the high costs associated with extremely preterm birth, which my colleague has just talked about, are for the minority of babies and children, because the impact of preterm birth, as I have just said, is much broader than that.

Around 2,000 babies are born extremely preterm in the UK each year. If you take the impact and the costs associated with late preterm birth, those babies represent around 75% of preterm births. Undoubtedly, their problems are less severe, but there are so many more of them that, in their impact on healthcare services and education—indeed, on costs across the board—they are a very significant group.

Q113       Baroness Cumberlege: Thank you for coming today to be our witnesses and to tell us more about this subject. I want to ask you about the impacts of preterm birth and what effects it has on adulthood and, then, perhaps into the workforce when these people have grown up. Does it have a lasting impact, or is it redressed as they get older?

Professor Elaine Boyle: A number of UK studies have looked at outcomes mostly into young adulthood, and there are others across Europe, the United States and Canada. They all show that there is a gradient of risk and that, for the most immature children, the greatest impact is mostly on their development, educational attainment and health in comparison with the least immature children.

However, there are some interesting things coming through in the most recent studies. The EPICure study that Stavros referred to is looking at the extremely preterm group, whose problems are undoubtedly more severe and likely to impact their schooling through their disabilities, learning difficulties and attention problems. Of course, that will have a knock-on effect on them finding employment and generally integrating into society as adults.

They also have chronic health conditions, which will have a bearing. In extremely preterm babies, these are often respiratory-related problems, particularly if they have severe lung disease as infants and are ventilated for a long time. Those things will come through into their later lives as well. We know that they are at high risk of learning difficulties and poor academic performance at school. Around two-thirds of them need additional support at school and a significant number need specialist full-time education.

The studies that have looked more broadly at educational and health needs have shown that these effects are not limited to the most immature babies. Some of the most alarming data looks at the health outcomes of more mature preterm babies. Across the health spectrum, these children also have problems. Multiple studies have now shown that they have an increased risk not only of early hospital admission but of hospital admission throughout their lifespan. In childhood, these are often related to infections and respiratory disorders even at the later gestations—for example, in children being born at 37 to 38 weeks—in comparison to those born just a couple of weeks later.

The Millennium Cohort Study, a national representative study that looked at children from nine months of age, showed a gradient of risk that stretches right across the spectrum but can be detected even with birth just a couple of weeks early. It is also reflected in parents’ views of their child’s health: if parents are asked about their children’s health, across the board they are more likely to say that their children are limited in what they can do because of their health. That often relates to respiratory outcomes.

Interestingly, in the light of what my colleague has just said about overweight and obesity, there seems to be a preponderance of overweight and obesity in more mature preterm infants, whereas very preterm babies tend to have more problems with underweight. Obesity seems to be a particular problem for more mature preterm babies.

You asked about adult outcomes, and perhaps I could just mention a few data that have come from Swedish studies suggesting that preterm birth is associated with an increased risk of cardiovascular disease, in particular hypertension and ischemic heart disease, and a greater risk of endocrine and metabolic disorders, with a 1.5 to 2 times increase in type 1 and type 2 diabetes in individuals who are born preterm. The pulmonary function, even in more mature preterm babies, seems to be impaired compared with babies born just a few weeks later, although some of that seems to resolve by their teenage years.

It is also important to recognise that they have a huge number of problems, of varying degrees of severity, but we also have to note that around 53% of all preterm births and 23% of extremely preterm individuals are alive in early adulthood with no major morbidities. So there is a balance there. Worryingly, the Swedish population data, which are routinely collected across the gestational age spectrum, suggest that there is a 30% to 50% higher all-cause mortality in preterm-born individuals aged between 18 and 45 years. That is very significant and seems to be related mainly to cardiovascular, endocrine and respiratory conditions and is there even if you adjust for all the other factors that might be at play there.

Q114       Baroness Cumberlege: You said that the start of life for some of these people has a long-term impact on them and limits the sorts of things that they can do. I imagine that is partly to do with access to higher education, for example, if that is what they want—the path of life. It inhibits what they can do. Is all of this picked up? Is any remedial action taken by professional people, families or whoever to enable them to get through some of this?

Professor Elaine Boyle: Babies who are born very preterm are followed up on closely at least until they are two years old and, if they have ongoing problems, far beyond that as they transition to paediatric care services. We would hope to be able to put in place whatever interventions might be helpful for people in that group, such as physiotherapy. I am sure you will hear about that in the next session.

On the health outcomes for the more mature preterm babies, many of those problems are not picked up until school age. Indeed, many of the health problems do not become evident until early adulthood or even middle age.

Q115       Baroness Hughes of Stretford: We have not looked at this as a committee yet, although we will in later sessions, but so many of the outcomes—you mentioned obesity, low educational attainment, and all that—that you are interested in when assessing the subsequent welfare of children born preterm are things that we know are also mediated strongly for all children by socioeconomic circumstances and, to some extent, by race. Can you tell us anything about any research that there may be on the interplay between those sorts of socioeconomic and demographic factors and the situation of being born too early?

The Chair: We know the effect of being born prematurely, per se, but what additional impact does being born prematurely and coming from a deprived background have?

Professor Elaine Boyle: Let me say straightaway that I do not have any numbers at my fingertips, but undoubtedly all the evidence points to socioeconomic status being very important in terms of the effects of gestational age. Children who are born into a less affluent background tend to do less well and tend to be those who get lost to follow-up. We know that it has an impact on whether families seek access to healthcare. With very preterm babies, it is probably clearer that a bigger effect of immaturity is at play. With more mature preterm babies, it is much less clear, and there may be some important environmental and socioeconomic factors.

Q116       Lord Winston: Given the incidence of obesity in some of these children even when they are not that preterm—that is really quite interesting—has anybody checked the epigenetic status of these babies in general? How much do we know about that with regard to disease in other respects, because clearly this is becoming more and more important?

Professor Elaine Boyle: The answer to your first question is that I do not know whether anyone has checked their epigenetic status, but I can certainly look into that and find out. There are a number of things at play. One may be socioeconomic status and affluence. Another may be the fact that these less immature, but early babies are still much less likely to be exposed to their mother’s breast milk. That may be a factor—I do not know; that is speculation—but we certainly know that these babies are much less likely to be breast fed and that, to some extent, breastfeeding appears to be protective against overweight and obesity later on. So there may be a role there.

Q117       Baroness Owen of Alderley Edge: You have already touched on some of these points, but I am interested to know whether we have sufficient data to determine the full cost and impact of preterm birth. If not, how can we improve on this?

Professor Stavros Petrou: We can certainly improve on our current knowledge. A number of studies have estimated the economic consequences of preterm birth, but they are limited in a number of respects. We are now embedding economic studies into longitudinal studies that are following up on these children for much longer into adulthood. We know very little about the economic consequences of preterm birth in terms of labour market outcomes, impacts on lost productivity and broader societal impacts. Even our knowledge of the impacts on parents and informal caregivers is quite limited.

There are a number of directions that we can go in in future that will broaden our knowledge in these respects. There are new research initiatives involving potentially embedding economic analyses into ECHILD, which is a record linkage study of health, education and social care records for all children born in England. We can build economic studies into those, but we also need to do primary research that not only broadens the perspectives of our analyses and aims to estimate the costs to families and to society as a whole—those studies will need to use primary research methods—but embeds economic studies into longitudinal cohorts into adulthood and beyond so that we get a broader, longer-term perspective on the economic impacts of preterm birth.

Professor Elaine Boyle: The data that we have on extremely preterm babies is pretty good. We have some excellent cohort studies, in particular the EPICure studies. The data that we have for the rest of the gestational age range is much less secure and is based mainly on retrospective data. The issue there is that, although sick and extremely preterm and very preterm babies are admitted to a neonatal unit and have data routinely collected, there is no such routine data collection for any baby born at 34 weeks and above unless they are sick.

However, the suggestion is that, even if they are not sick in the neonatal period, these babies are at higher risk as they age, so I would love to have routinely collected data across the gestational age range. If we do not have routine data, cohort studies looking at large numbers of babies are extremely expensive, so broadening our data collection would be a good investment.

We also need to increase awareness across the board of the outcomes of preterm birth. That this is an important question to ask should be highlighted to adult physicians, general practitioners and anybody else who deals with adults and children who have been born preterm.

Q118       Baroness Owen of Alderley Edge: I am not sure whether you have the data to hand. We are often given the numbers and figures, but how much does a child born at term cost up to the age of 18, for comparison?

Professor Stavros Petrou: We conducted a study called TIGAR, which used hospital episode statistics to look at the admission costs associated with birth at different gestational ages. It did not follow children up to 18 years of age—they were born in 2005 and were followed up on only to adolescence—but we noted an additional cost associated with early term birth compared to birth at 39 to 41 weeks. The cost difference was in eight-year cumulative hospital admission costs, so for the first eight years of life only, but it was certainly less than £1,000 for early term compared to birth at full term. The difference was £3,000 versus £4,000, or something in that sort of range.[3]

Baroness Owen of Alderley Edge: For early term versus full term.

Professor Stavros Petrou: Yes.

Baroness Owen of Alderley Edge: So there was a difference of about £1,000. Was that per year?

Professor Stavros Petrou: No. It was over the first eight years of life. That is for early term versus full term. For births at extremely low gestational ages, the cost differences were much larger; they were closer to £80,000.

The Chair: These are costs to whom?

Professor Stavros Petrou: The TIGAR study looked at costs to the NHS, but it was limited to hospital admission costs. It did not cover hospital out-patient costs, the costs of hospital accident and emergency visits, community health costs or social service costs, for example. It had quite a narrow perspective.

Q119       Baroness Owen of Alderley Edge: I think you have answered my question by explaining that it does not cover all the costs, but do we have anything that looks at all of them? That would be a truer comparison of the cost of being at full term versus not.

Professor Stavros Petrou: Certainly, the LAMBS cohort in the study that Elaine Boyle led looked at costs during the first two years of life associated with moderate and late preterm birth versus birth at full term. That took a broad societal perspective that encompassed costs to the health services, social services and other parts of the public sector. It also included costs to families and informal carers. There, we noticed that costs borne by families constituted about 10% of total societal costs.

Q120       Baroness Owen of Alderley Edge: Is there any plan to get more data, and is that seen as a need within the industry?

Professor Stavros Petrou: Yes, we are trying to embed economic analyses into various prospective cohort studies. It is quite difficult to get funding to do this type of research, but we are using a combination of research methods to gather data using different research methodologies—for example, embedding primary costing studies into prospective cohort studies. We also use modelling methods such as decisional modelling, which pulls together data from different sources, including from the literature, to estimate costs from a broad perspective but over a longer-term time horizon as well.

Q121       The Chair: You are a bit reticent, Professor Petrou. You have a lot of information and we need to tease it out of you. On the one hand, we hear that there is an enormous amount of morbidity in babies born preterm. The more preterm they are, the greater the numbers and severity of their morbidity. Clearly, that must have cost implications not only for the services but for the families. If we are to make a case for a better service for babies born preterm, or for support to the families, we need to know figures—data. We also need to know where the data gap is, so that we can make a case for getting that data for better services. So which is it? Be bold.

Professor Stavros Petrou: Certainly. We have estimated costs based on a number of different studies that give us part of the picture. The first study I mentioned was quite a comprehensive modelling study that pulled together data from lots of sources and estimated the economic consequences during childhood associated with preterm birth at almost £4.5 billion. Each study has its own limitations in the time horizon that it has adopted, the types of costs that it has captured, and so on.

There is no single study that will answer that question, so we have to piece together evidence from a number of studies to make a case about the importance of this topic and the burden of preterm birth, and that is what we are doing in our research: we are piecing together evidence using methodologies based on different study designs to build up a picture about the economic impacts of preterm birth.

It is difficult to generalise across all the studies, because they all adopt slightly different methodologies, so it would not be accurate for me to say that the total economic cost of preterm birth is X and that the proportion made up of costs to health services is Y. We are building up an evidence base that is increasing knowledge in this area, but there is no single study that will give you the totality of the picture.

The Chair: So do you have a cumulative of all the studies that has a clear message?

Professor Stavros Petrou: I think the big message would be that if we could come up with an intervention that delayed preterm birth by a week across the gestational ages, we would save at least £1 billion a year for the public sector. That is quite clear, based on the evidence from our studies.

The Chair: Did you say £1 million?

Professor Stavros Petrou: £1 billion.

The Chair: Right. Now we are getting somewhere.

Professor Stavros Petrou: I would say that is a conservative estimate of the potential cost savings to the public sector. If we could come up with an intervention that was effective, safe and cost effective, and if implementing it delayed preterm birth across the gestational age spectrum, that would have a huge impact in potential savings to the public sector.

The Chair: Thank you both. We have not quite exhausted you, but you have certainly given a lot of information to go by, particularly what you just said about what the savings would be in preventing preterm by even a week. That was most helpful, and I am sorry for pushing you a bit.