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.
Keeping my podcast running without ads or sponsorship is important to me. I want to keep it free and accessible to all but it costs me a small amount each month to maintain and keep the episodes live, if you wish to contribute anything to support theobspod please head over to my buy me a coffee page https://bmc.link/theobspodV any donation very gratefully received however small.
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...

Episode Transcript

Speaker 1 (00:00):
Hello, my name is Florence.
Welcome to the ObsPod.
I'm an NHS obstetrician hopingto share some thoughts and
experiences about my workinglife.
Perhaps you enjoy Call theMidwife, maybe birth fascinates
you, or you're simply curiousabout what exactly an
obstetrician is.
You might be pregnant andpreparing for birth.

(00:21):
Perhaps you work in maternityand want to know what makes your
obstetric colleagues tick, oryou want some fresh ideas and
inspiration.
Whichever of these is the caseand, for that matter, anyone
else that's interested, theObsPod is for you.
Episode 159.

(00:50):
Sleep position in pregnancy.
Sometimes I feel that we setpregnant women an impossible
task.
There is so much that you needto think about what to eat, what
to drink, what not to eat, whatnot to drink, what not to smoke

(01:15):
, not to be near other smokers,and one of the things about this
list of do's and don'ts inpregnancy is it's ever changing,
it's ever evolving.
So advice you might have beengiven when you had your children

(01:37):
might not be the advice givento your daughter when she has
her children.
And if you've had a gap in yourfamily and you had one baby,
maybe five or 10 years ago, theadvice that you're given now may
be very different from what youwere given back then.

(01:59):
As a professional, it can feelhard to keep up.
Yes, we do CPD, we're doingprofessional development, but
sometimes new information comesout and we're not quite up to
speed with it.
This topic what position tosleep in is something that's

(02:25):
kind of crept up over the lastfew years.
We started to see researchpublished about what position
pregnant women should besleeping in, and I've picked it
for a topic today because it isa question I get asked in clinic
quite a lot.
So where do we begin?

(02:48):
Well, I'm going.
There is evidence that suggeststhat the best position to sleep
in when you're pregnant is onyour left side, and the evidence
is that this is safest becauseit reduces the chance of

(03:10):
stillbirth, and anyone pregnantwill tell you that stillbirth is
their worst nightmare.
Therefore, women take thisadvice very seriously.
I've always found it difficultwhen women come to me in clinic

(03:32):
and say well, I try and go tosleep on my left side, but when
I wake up I'm in all sorts ofdifferent positions, and I think
if we're not careful with thisadvice, we can make women feel
guilty for being in the wrongposition, something which, after
all, they cannot control,because they're unconscious

(03:55):
while they're asleep, andeveryone knows from watching
videos of sleeping people, whichsometimes pop up on television
programs or adverts for perhapsthe comfiest mattress, etc.
That we move around anincredible amount in our sleep
and we don't have any controlover that.

(04:17):
So when women come to clinicand tell me they're really
struggling to get to sleep ontheir side or on their left side
and they're really worriedbecause they wake up in all
sorts of different positions andthey're also really worried
because they're struggling toget good quality sleep because

(04:38):
they're so anxious about theposition in which they're lying
I find it very difficult toreassure them.
The evidence is out there andyet we're setting them an
impossible task.
So for some time I've beenthinking I should have a look at
the evidence behind this, andthat's what I'm going to focus

(05:01):
on today.
And the reason I've decided todo that this week is I saw some
studies pop up on my Twitterfeed coming back to more
evidence about sleeping positionin pregnancy, so it's topical
just at the moment.
I will come to the papers thatI saw publicised on Twitter,

(05:31):
because they're looking at justhow sleep position might impact
on the growth of the baby andthe chance of stillbirth.
But first of all, I thought I'dbe able to give you a look at
the results and, first of all, Ithought I'd look at the
evidence that it does affect thebaby's growth and chance of

(05:53):
stillbirth.
In preparation for the episode Idiscovered, would you believe
that there is some actual niceguidance on maternal sleep
position during pregnancy?
Who knew?
Well, I didn't, and that sayssomething, doesn't it?

(06:14):
It was published in August 2021.
But clearly, although I knowthere is some advice now about
sleep position, I wasn't awareof the detailed documentation
about the evidence from NICE.
So that says something aboutdissemination and implementation

(06:35):
.
So the nice guidance which I'veput in the show notes asks us
the question is there anassociation between sleep
position on going to sleep andstillbirth or having a small,
for gestational age baby, growthrestricted baby?

(06:58):
And it looked at a whole seriesof studies and there are some
quite nice tables about thedifferent studies and
discussions about the differentstudies which you can have a
look at.
The first thing that I thoughtwhen I looked at this was that

(07:23):
they talked about supine, thatis, lying on your back, prone,
lying on your front, left,lateral, right, lateral variable
propped up.
So they looked at a wholenumber of sleep positions.

(07:44):
The other thing that I realizedis that the latest studies
talked about going to sleepposition, so at no point had I
realized that the evidence wasbased on thinking about what

(08:06):
position you were when you weretrying to go to sleep, and I'd
always wondered about this sortof nonsensical idea that you
could recall and decide whatposition a woman had slept in
overnight when no one'snecessarily observing her and
she's unconscious so shewouldn't know.

(08:26):
So I felt relieved that theywere actually sensibly looking
at going to sleep position andthey also looked at quite a lot
of confounding variables.
If you want a really nicesummary of all the evidence,

(08:49):
I've also put a link to theTommy's website where Professor
Hazel, who undertook one of thestudies, does a really nice four
minute video summary of theevidence, how the evidence has
progressed, what each study hasadded over time and what the

(09:10):
impact of those are, and howthey tried to refine the studies
to reduce the number ofconfounding variables and also
the fact that women, when askedwhat position they slept in,
might recall inaccuratelyso-called recall bias.

(09:35):
The evidence is that there ishigh quality evidence that lying
flat on your back, supine, whengoing to sleep, increases the
chance of stillbirth by aboutthreefold and increases the
chance of a small, great,restricted baby by about

(09:59):
threefold.
So there is very clear evidence.
But it is about the positiongoing to sleep position, not
what position you're atovernight.
The next thing which I think isreally important and perhaps

(10:22):
has got lost in the messaging towomen, is that sleeping on your
left side, right side, proppedup those positions there is no
difference between them in termsof outcome.
And definitely, whilst I'vebelieved this in reassured women

(10:46):
in clinic, I hadn't quitegrasped that there was such
concrete evidence that if I givea woman advice to maybe lie on
the other side or sleep proppedup, that there is evidence that
that's okay.

(11:07):
And when we give women advicewe've got to be practical.
If a woman's telling me shecan't sleep on her left it makes
her sick, for example or shejust can't get comfortable or
she can't sleep she's losingsleep.
That can't be good for her andher baby either.
So to be able to confidentlysay to her actually the evidence

(11:29):
suggests that if you propyourself up with a load of
pillows, that's fine, or if youprefer lying on your right side,
that's fine Is very helpful, Ithink when we're talking to
women about sleeping on theirback.
We're not explaining that.
We mean flat on their back, andwhen you look at the studies,

(11:54):
it's very clear that they aretalking about flat on their back
.
If you watch the four minutevideo I mentioned with Professor
Hazel, it not only gives youthe information about the
research on which this adviceabout sleeping position is based

(12:16):
, but it also gives a clearmessage that, whilst we spend a
lot of time and effort thinkingabout women smoking in pregnancy
and indeed I've previously donean episode on smoking in
pregnancy that actually talkingto women about their sleep

(12:39):
position could save more baby'slives than talking to women
about smoking.
That fact absolutely blew mymind.
I don't think that we're havingregular conversations with
women about sleep position orperhaps the midwives are and I'm

(13:04):
not but I do find it crops upas a question that women ask me
and fret about, and whilst it'sgreat that we can give out these
public health messages andinformation, I also worry
slightly about hammering homethese messages and this

(13:27):
information.
Because then are we saying, ifyou went to sleep in the wrong
position, we're inferring itmight be your fault that the
baby is not growing well or yourfault that your baby died.
There's a very fine linebetween giving a woman a sense

(13:51):
of responsibility for her healthand that of her baby and making
her feel that somehow she'sresponsible if the outcome isn't
good, when actually we knowthere are a myriad of other
factors that come into play andthat there are many things over

(14:15):
which a woman has absolutely nocontrol whatsoever.
Yet if we are not giving outthis messaging, then we are
being irresponsible by notgiving women information so that
they can take decisions abouthow they're living their lives

(14:35):
and looking after their healthand that of their baby during
their pregnancy.
So it's a very tricky balance.
So the reason this popped up onmy Twitter feed this week was
they published some interestingstudies where they actually
tried to figure out why theposition you sleep in might make

(14:58):
this difference, and the waythey did this was they actually
MRI scanned women and babies inthird trimester, comparing women
with a so-called healthypregnancy and women with a
growth restricted pregnancy.

(15:18):
And it's absolutely fascinatingbecause they put women in left
lateral for 25 minutes and thenwomen on their flat, on their
backs, for 25 minutes and thenmeasured blood flow and fetal
oxygen saturation.

(15:38):
And this is an extraordinarystudy because it showed that
lying supine caused a 3.8%reduction in fetal oxygen
saturation and significantreductions in placental blood
flow compared with left lateral.

(15:59):
Interestingly, they found thatgrowth-restricted babies also
had a difference in blood flowand oxygen saturation in
comparison with healthypregnancies, but that lying flat

(16:20):
on the woman's back had anadditive effect.
So if you have a small,growth-restricted baby and then
you lie on your back, that willhave a further reduction in
oxygen transfer.
So a chronically hypoxic,struggling baby and then you lie
on your back have a greaterdecline in their oxygen transfer

(16:45):
than a mother carrying aso-called normally-grown baby.
The numbers are small, but Ifind this study absolutely
fascinating and may help reallyunpick all sorts of things about
our assumptions about babies,growth and placental function,

(17:12):
which I'm sure will be an avenuefor research in the future.
In the meantime, where are we atwith sleeping position?
What is my zesty bit this week?
Firstly, don't underestimatehow incredibly difficult it is

(17:36):
to sleep when you're pregnant.
I remember clearly thedifficulties I faced sleeping
when I was pregnant for thefirst time with my older child,
who is about to be 25.
I had habitually slept on mytummy, so-called prone position.

(17:57):
I never wanted to sleep flat onmy back, despite there not
being the evidence that there isnow for that being harmful,
because I struggled withterrible heartburn.
So I was in the position whereI had to sleep on my side
propped up with lots of pillows,and it was tough, really tough,

(18:18):
and I think if someone at thatpoint had added in oh and, by
the way, if you sleep in thewrong position, this might cause
your baby to have growthproblems or, worse still,
stillbirth, I think it wouldhave been impossible.
So we need to be clear whenwe're giving women information,

(18:42):
that we should give theminformation about not sleeping
flat on their back or supine,and that the optimum position is
indeed left lateral.
But we must explain to themthat that is the going to sleep
position and it doesn't matterif they wake up in the middle of
the night and they're in acompletely different position

(19:03):
and that, equally, if they wantto sleep propped up with a load
of pillows or on their rightside, that is equally safe and
not a problematic thing for themto do.
Alongside the video I mentionedon the Tommy's research
background to the sleepingadvice is a nice one minute

(19:26):
video for women which detailsthis.
Actually, this is somethingthat's been around for a bit,
but up until now I haven'tactually really looked at the
research behind the advice andthought about the fact that,

(19:47):
just as with smoking, everycontact counts and that actually
talking to women about sleep isan important element of giving
good antinatal care and thateducation.
So if you can spare the time, Iwould head on over to those two
little videos I mentioned, orhave a little pick through the

(20:11):
nice guidance and educateyourself, as I have done in
preparation for this episode, sothat you can confidently give
women the right advice aboutsafe sleeping position in
pregnancy.
I really hope that if you'relistening to this and you're

(20:33):
currently pregnant, I've setyour mind at rest that what is
important is the going to sleepposition and to sleep in any
position other than flat on yourback is okay and even though it
might seem challenging at thismoment in time, you might even
discover that the position youadopt to sleep in pregnancy ends

(20:58):
up being your favorite positionever more, because that's
what's happened for me I nowsleep on my right side and
that's my comfy go to, and thatwould have never happened if I
hadn't had to change my sleepingposition in pregnancy.

(21:20):
I very much hope you found thisepisode of the OBSPod
interesting.
If you have, it'd be fantasticIf you could subscribe, rate and
review, on whatever platformyou find, your podcasts, as well
as recommending the OBSPod toanyone you think might find it

(21:40):
interesting.
There's also tons of episodesto explore in my back catalogue
from clinical topics, my careerand journey as an obstetrician
and life in the NHS moregenerally.
I'd like to assure women I carefor that I take confidentiality
very seriously and take greatcare not to use any patient

(22:05):
identifiable information unlessI have expressly asked the
permission of the personinvolved on that rare occasion
when it's been absolutelynecessary.
If you found this episodeinteresting and want to explore
the subject a little more deeply, don't forget to take a look at

(22:29):
the programme notes, where I'veattached some links.
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(22:49):
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(23:11):
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