Episode 159 Sleep position in Pregnancy

Ever felt confused or guilty about your sleep position during pregnancy? Fear not, as I, Florence, an experienced NHS obstetrician, guide you through the maze of advice on this critical topic. Drawing from years of practice, continued learning and the latest research, I shed light on this topic, putting to rest unfounded fears and guilt. Together, we explore the NICE guidelines and dissect multiple research studies that have explored the impact of sleep position on stillbirth and fetal growth. My goal is to provide you with evidence-based knowledge, giving you the confidence and peace of mind you need during this special time.

In addition, we dive into a fascinating MRI study that demonstrates how different sleep positions affect fetal oxygen saturation and placental blood flow. The importance of the position you aim to sleep in, not the one you wake up in, is highlighted.

Want to know more:
https://www.nice.org.uk/guidance/ng201/evidence/w-maternal-sleep-position-during-pregnancy-pdf-331305934396
https://www.tommys.org/pregnancy-information/im-pregnant/sleep-side/sleep-side-research-behind-campaign
https://www.tommys.org/pregnancy-information/im-pregnant/sleep-side/sleep-position-pregnancy-qa
https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP284269

As I continue my quest to make obstetric care more accessible, we discuss ways you can support TheObsPod and help keep this platform free for all. Hear about how you can contribute and get involved, suggesting topics for future episodes. So, join me on this journey, as we bridge the gap between medical professionals and expectant mothers, one podcast episode at a time.

Thank you all for listening, My name is Florence Wilcock I am an NHS doctor working as an obstetrician, specialising in the care of both mother and baby during pregnancy and birth. If you have enjoyed my podcast please do continue to subscribe, rate, review and recommend my podcast on your podcast provider.
If you have found my ideas helpful whilst expecting your baby or working in maternity care please spread the word & help theobspod reach other parents or staff who may be interested in exploring all things pregnancy and birth.
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Its easy to explore my back catalogue of episodes here https://padlet.com/WhoseShoes/TheObsPod I have a wide range of topics that may help you make decisions for yourself and your baby during pregnancy as well as some more reflective episodes on life as a doctor.
If you want to get in touch to suggest topics, I love to hear your thoughts and ideas. You can find out more about me on Twitter @FWmaternity & @TheObsPod as well as Instagram @TheObsPod and e...

Transcript

Speaker 1: 0:00

Hello, my name is Florence. Welcome to the ObsPod. I'm an NHS obstetrician hoping to share some thoughts and experiences about my working life. Perhaps you enjoy Call the Midwife, maybe birth fascinates you, or you're simply curious about what exactly an obstetrician is. You might be pregnant and preparing for birth. Perhaps you work in maternity and want to know what makes your obstetric colleagues tick, or you want some fresh ideas and inspiration. Whichever of these is the case and, for that matter, anyone else that's interested, the ObsPod is for you. Episode 159. Sleep position in pregnancy.

Speaker 1: 0:55

Sometimes I feel that we set pregnant women an impossible task. There is so much that you need to think about what to eat, what to drink, what not to eat, what not to drink, what not to smoke, not to be near other smokers, and one of the things about this list of do's and don'ts in pregnancy is it's ever changing, it's ever evolving. So advice you might have been given when you had your children might not be the advice given to your daughter when she has her children. And if you've had a gap in your family and you had one baby, maybe five or 10 years ago, the advice that you're given now may be very different from what you were given back then. As a professional, it can feel hard to keep up. Yes, we do CPD, we're doing professional development, but sometimes new information comes out and we're not quite up to speed with it. This topic what position to sleep in is something that's kind of crept up over the last few years. We started to see research published about what position pregnant women should be sleeping in, and I've picked it for a topic today because it is a question I get asked in clinic quite a lot. So where do we begin? Well, I'm going. There is evidence that suggests that the best position to sleep in when you're pregnant is on your left side, and the evidence is that this is safest because it reduces the chance of stillbirth, and anyone pregnant will tell you that stillbirth is their worst nightmare. Therefore, women take this advice very seriously.

Speaker 1: 3:29

I've always found it difficult when women come to me in clinic and say well, I try and go to sleep on my left side, but when I wake up I'm in all sorts of different positions, and I think if we're not careful with this advice, we can make women feel guilty for being in the wrong position, something which, after all, they cannot control, because they're unconscious while they're asleep, and everyone knows from watching videos of sleeping people, which sometimes pop up on television programs or adverts for perhaps the comfiest mattress, etc. That we move around an incredible amount in our sleep and we don't have any control over that. So when women come to clinic and tell me they're really struggling to get to sleep on their side or on their left side and they're really worried because they wake up in all sorts of different positions and they're also really worried because they're struggling to get good quality sleep because they're so anxious about the position in which they're lying I find it very difficult to reassure them. The evidence is out there and yet we're setting them an impossible task. So for some time I've been thinking I should have a look at the evidence behind this, and that's what I'm going to focus on today. And the reason I've decided to do that this week is I saw some studies pop up on my Twitter feed coming back to more evidence about sleeping position in pregnancy, so it's topical just at the moment. I will come to the papers that I saw publicised on Twitter, because they're looking at just how sleep position might impact on the growth of the baby and the chance of stillbirth. But first of all, I thought I'd be able to give you a look at the results and, first of all, I thought I'd look at the evidence that it does affect the baby's growth and chance of stillbirth.

Speaker 1: 5:56

In preparation for the episode I discovered, would you believe that there is some actual nice guidance on maternal sleep position during pregnancy? Who knew? Well, I didn't, and that says something, doesn't it? It was published in August 2021. But clearly, although I know there is some advice now about sleep position, I wasn't aware of the detailed documentation about the evidence from NICE. So that says something about dissemination and implementation. So the nice guidance which I've put in the show notes asks us the question is there an association between sleep position on going to sleep and stillbirth or having a small, for gestational age baby, growth restricted baby?

Speaker 1: 6:58

And it looked at a whole series of studies and there are some quite nice tables about the different studies and discussions about the different studies which you can have a look at. The first thing that I thought when I looked at this was that they talked about supine, that is, lying on your back, prone, lying on your front, left, lateral, right, lateral variable propped up. So they looked at a whole number of sleep positions. The other thing that I realized is that the latest studies talked about going to sleep position, so at no point had I realized that the evidence was based on thinking about what position you were when you were trying to go to sleep, and I'd always wondered about this sort of nonsensical idea that you could recall and decide what position a woman had slept in overnight when no one's necessarily observing her and she's unconscious so she wouldn't know. So I felt relieved that they were actually sensibly looking at going to sleep position and they also looked at quite a lot of confounding variables. If you want a really nice summary of all the evidence, I've also put a link to the Tommy's website where Professor Hazel, who undertook one of the studies, does a really nice four minute video summary of the evidence, how the evidence has progressed, what each study has added over time and what the impact of those are, and how they tried to refine the studies to reduce the number of confounding variables and also the fact that women, when asked what position they slept in, might recall inaccurately so-called recall bias.

Speaker 1: 9:35

The evidence is that there is high quality evidence that lying flat on your back, supine, when going to sleep, increases the chance of stillbirth by about threefold and increases the chance of a small, great, restricted baby by about threefold. So there is very clear evidence. But it is about the position going to sleep position, not what position you're at overnight. The next thing which I think is really important and perhaps has got lost in the messaging to women, is that sleeping on your left side, right side, propped up those positions there is no difference between them in terms of outcome. And definitely, whilst I've believed this in reassured women in clinic, I hadn't quite grasped that there was such concrete evidence that if I give a woman advice to maybe lie on the other side or sleep propped up, that there is evidence that that's okay.

Speaker 1: 11:07

And when we give women advice we've got to be practical. If a woman's telling me she can't sleep on her left it makes her sick, for example or she just can't get comfortable or she can't sleep she's losing sleep. That can't be good for her and her baby either. So to be able to confidently say to her actually the evidence suggests that if you prop yourself up with a load of pillows, that's fine, or if you prefer lying on your right side, that's fine Is very helpful, I think when we're talking to women about sleeping on their back. We're not explaining that. We mean flat on their back, and when you look at the studies, it's very clear that they are talking about flat on their back.

Speaker 1: 12:00

If you watch the four minute video I mentioned with Professor Hazel, it not only gives you the information about the research on which this advice about sleeping position is based, but it also gives a clear message that, whilst we spend a lot of time and effort thinking about women smoking in pregnancy and indeed I've previously done an episode on smoking in pregnancy that actually talking to women about their sleep position could save more baby's lives than talking to women about smoking. That fact absolutely blew my mind. I don't think that we're having regular conversations with women about sleep position or perhaps the midwives are and I'm not but I do find it crops up as a question that women ask me and fret about, and whilst it's great that we can give out these public health messages and information, I also worry slightly about hammering home these messages and this information. Because then are we saying, if you went to sleep in the wrong position, we're inferring it might be your fault that the baby is not growing well or your fault that your baby died. There's a very fine line between giving a woman a sense of responsibility for her health and that of her baby and making her feel that somehow she's responsible if the outcome isn't good, when actually we know there are a myriad of other factors that come into play and that there are many things over which a woman has absolutely no control whatsoever. Yet if we are not giving out this messaging, then we are being irresponsible by not giving women information so that they can take decisions about how they're living their lives and looking after their health and that of their baby during their pregnancy. So it's a very tricky balance.

Speaker 1: 14:45

So the reason this popped up on my Twitter feed this week was they published some interesting studies where they actually tried to figure out why the position you sleep in might make this difference, and the way they did this was they actually MRI scanned women and babies in third trimester, comparing women with a so-called healthy pregnancy and women with a growth restricted pregnancy. And it's absolutely fascinating because they put women in left lateral for 25 minutes and then women on their flat, on their backs, for 25 minutes and then measured blood flow and fetal oxygen saturation. And this is an extraordinary study because it showed that lying supine caused a 3.8% reduction in fetal oxygen saturation and significant reductions in placental blood flow compared with left lateral. Interestingly, they found that growth-restricted babies also had a difference in blood flow and oxygen saturation in comparison with healthy pregnancies, but that lying flat on the woman's back had an additive effect. So if you have a small, growth-restricted baby and then you lie on your back, that will have a further reduction in oxygen transfer. So a chronically hypoxic, struggling baby and then you lie on your back have a greater decline in their oxygen transfer than a mother carrying a so-called normally-grown baby. The numbers are small, but I find this study absolutely fascinating and may help really unpick all sorts of things about our assumptions about babies, growth and placental function, which I'm sure will be an avenue for research in the future.

Speaker 1: 17:20

In the meantime, where are we at with sleeping position? What is my zesty bit this week? Firstly, don't underestimate how incredibly difficult it is to sleep when you're pregnant. I remember clearly the difficulties I faced sleeping when I was pregnant for the first time with my older child, who is about to be 25. I had habitually slept on my tummy, so-called prone position. I never wanted to sleep flat on my back, despite there not being the evidence that there is now for that being harmful, because I struggled with terrible heartburn. So I was in the position where I had to sleep on my side propped up with lots of pillows, and it was tough, really tough, and I think if someone at that point had added in oh and, by the way, if you sleep in the wrong position, this might cause your baby to have growth problems or, worse still, stillbirth, I think it would have been impossible. So we need to be clear when we're giving women information, that we should give them information about not sleeping flat on their back or supine, and that the optimum position is indeed left lateral. But we must explain to them that that is the going to sleep position and it doesn't matter if they wake up in the middle of the night and they're in a completely different position and that, equally, if they want to sleep propped up with a load of pillows or on their right side, that is equally safe and not a problematic thing for them to do.

Speaker 1: 19:17

Alongside the video I mentioned on the Tommy's research background to the sleeping advice is a nice one minute video for women which details this. Actually, this is something that's been around for a bit, but up until now I haven't actually really looked at the research behind the advice and thought about the fact that, just as with smoking, every contact counts and that actually talking to women about sleep is an important element of giving good antinatal care and that education. So if you can spare the time, I would head on over to those two little videos I mentioned, or have a little pick through the nice guidance and educate yourself, as I have done in preparation for this episode, so that you can confidently give women the right advice about safe sleeping position in pregnancy. I really hope that if you're listening to this and you're currently pregnant, I've set your mind at rest that what is important is the going to sleep position and to sleep in any position other than flat on your back is okay and even though it might seem challenging at this moment in time, you might even discover that the position you adopt to sleep in pregnancy ends up being your favorite position ever more, because that's what's happened for me I now sleep on my right side and that's my comfy go to, and that would have never happened if I hadn't had to change my sleeping position in pregnancy.

Speaker 1: 21:20

I very much hope you found this episode of the OBSPod interesting. If you have, it'd be fantastic If you could subscribe, rate and review, on whatever platform you find, your podcasts, as well as recommending the OBSPod to anyone you think might find it interesting. There's also tons of episodes to explore in my back catalogue from clinical topics, my career and journey as an obstetrician and life in the NHS more generally. I'd like to assure women I care for that I take confidentiality very seriously and take great care not to use any patient identifiable information unless I have expressly asked the permission of the person involved on that rare occasion when it's been absolutely necessary.

Speaker 1: 22:18

If you found this episode interesting and want to explore the subject a little more deeply, don't forget to take a look at the programme notes, where I've attached some links. If you want to get in touch to suggest topics for future episodes, you can find me at the OBSPod, on Twitter and Instagram and you can email me theobspod at gmailcom. Finally, it's very important to me to keep the OBSPod free and accessible to as many people as possible, but it does cost me a very small amount to keep it going and keep it live on the internet. So if you've enjoyed my episodes and by chance, you do have a tiny bit to spare. You can now contribute to keep the podcast going and keep it free via my link to buy me a coffee. Don't feel under any obligation, but if you'd like to contribute you now can. Thank you for listening.