Sleep position in pregnancy Q&A

In the third trimester of pregnancy going to sleep on your side has been shown to help prevent stillbirth.

In the third trimester our advice is to go sleep on your side because research has shown that this is safer for baby. This includes night sleep and day time naps.

Can I sleep on my back during pregnancy?

Research has shown that in the third trimester (after 28 weeks of pregnancy) going to sleep on your back increases your risk of stillbirth. As the link has now been shown in four separate research trials, our advice is to go to sleep on your side in the third trimester because it is safer for your baby. The advice relates to any episode of sleep, including:

  • going to sleep at night
  • returning to sleep after any night wakenings
  • day time naps.

We don’t want you to become anxious about this. If your pregnancy is uncomplicated your risk of stillbirth is low (1 in 200 babies are stillborn). Going to sleep on your side will make it even lower.

How reliable is the research?

The research linking going to sleep on your back to stillbirth is very reliable. Four case control research studies (in which information from women who have had a stillbirth is compared with information from women who have not) have been carried out into maternal sleep position and stillbirth and all have shown that there is a link.

What if I wake up on my back during the night?

The research has been focused on position going to sleep, not position during the night. If you wake up on your back, just settle back to sleep on your side.

We cannot control our position when we are asleep and a large bump is likely to be uncomfortable enough to prevent you from being on your back for long during the night. We also know that the position we go to sleep in is the position we spend the longest amount of time in during the night.

What could cause the increased risk of stillbirth?

Sleep position in the third trimester is important because if you are on your back the combined weight of baby and womb puts pressure on other organs in your body.

Researchers do not know for certain what exactly is causing the increased risk of stillbirth, but we already know the following, which could play a part :

  • When sleeping/lying on your back the baby and womb put pressure on the main blood vessels that supply the uterus and this can restrict blood flow/oxygen to the baby.
  • Further recent studies have shown that when a woman lies on her back in late pregnancy (compared to lying on side) the baby is less active and has changes in heart-rate patterns. This is thought to be due to lower oxygen levels in the baby when the mother lies on her back.

Does it make a difference which side I sleep on in pregnancy?

There are many websites that tell you that the left side is best to sleep on during pregnancy. This is for the following reasons:

  • One of the smaller research studies, from Auckland, New Zealand, showed that women who sleep on their left side on the last night of pregnancy halved their risk of stillbirth compared to those who slept on their right. However, the same finding has not been seen in any other trial (there have been three other published research studies since then).
  • Sleeping on your left has been shown to help your kidneys to get rid of waste products and fluids from your body.

Therefore, while sleeping on your left side has not conclusively been shown to reduce your risk against sleeping on your right, there are reasons that you might choose to do so.

Tips for sleeping on your side in pregnancy

  • Put pillows behind you to prevent falling on your back. It won’t prevent you being on your back for certain but is likely to make it more uncomfortable.
  • If you have long hair, try tying it in a low bun, which may make it uncomfortable to sleep on your back for any length of time.
  • If you wake up for any reason during the night, check your position and go back to sleep on your side.
  • If you are likely to nap during the day pay the same attention to sleep position during the day as you would during the night.

If you're finding sleeping on your side difficult because of SPD/PGP, try these tips.

Is it harmful to sleep on my stomach in pregnancy?

In the early days of pregnancy it is fine to sleep on your stomach. Your bump will not start showing until the second trimester and sleeping on your stomach is unlikely to be uncomfortable. In the third trimester, you will have a large bump and it is very unlikely that you would choose this position. However, if you do wake up on your stomach, don’t worry, just roll onto your side.


Heazell AEP, Li M, Budd J, Thompson JMD, Stacey T, Cronin RS, Martin B, Roberts D, Mitchell EA, McCowan LME. Association between maternal sleep practices and late stillbirth – findings from a stillbirth case-control study. BJOG2017;

Stacey T1, Thompson JM, Mitchell EA, Ekeroma AJ, Zuccollo JM, McCowan LM.
Association between maternal sleep practices and risk of late stillbirth: a case-control study. BMJ. 2011 Jun 14;342:d3403. doi: 10.1136/bmj.d3403.

Gordon A1, Raynes-Greenow C, Bond D, Morris J, Rawlinson W, Jeffery H. Sleep position, fetal growth restriction, and late-pregnancy stillbirth: the Sydney stillbirth study. Obstet Gynecol. 2015 Feb;125(2):347-55. doi: 10.1097/AOG.0000000000000627.

Lesley ME, McCowan LME, Thompson JMD, Cronin RS et al (2017) Going to sleep in the supine position is a modifiable risk factor for late pregnancy stillbirth; Findings from the New Zealand multicentre stillbirth case-control study. PLOS One

Jeffreys RM, Stepanchak W, Lopez B, Hardis J, Clapp JF, 3rd. Uterine blood flow during supine rest and exercise after 28 weeks of gestation. BJOG : an international journal of obstetrics and gynaecology. 2006 Nov;113(11):1239-47

Khatib N, Weiner Z, Beloosesky R, Vitner D, Thaler I. The effect of maternal supine position on umbilical and cerebral blood flow indices. European journal of obstetrics, gynecology, and reproductive biology. 2014 Apr;175:112-4.

Stone PR, Burgess W, McIntyre JP, Gunn AJ, Lear CA, Bennet L, et al. Effect of maternal position on fetal behavioural state and heart rate variability in healthy late gestation pregnancy. The Journal of Physiology. 2017 Feb 15;595(4):1213-21.

Murray I, Hassall J. 2014. Change and adaptation in pregnancy. In: Marshall J, Raynor M. eds. Myles Textbook for Midwives. 16th ed. Edinburgh: Churchill Livingstone, 143-177

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Read about the Sleep On Side campaign

    Last reviewed on November 20th, 2017. Next review date November 20th, 2020.

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    Please note that these comments are monitored but not answered by Tommy’s. Please call your GP or maternity unit if you have concerns about your health or your baby’s health.
    • By Alichea (not verified) on 14 Apr 2020 - 22:26

      Hello I have heard that it is better to lye on your left side than right. Is this true or does it not matter. I’m 24wks and I’m now getting more uncomfortable. Thank you.

    • By Anonymous (not verified) on 12 Mar 2020 - 13:48

      Hii .. I am 36 weeks pregnant these past few weeks I have this wired thinking and feeling worrying about my baby ... the question keeps popping my mind over and over again if my baby is ok in my womb... I can feel all the movement and kicking ... whenever I go to the doctor I have been told my baby heart beats is good too ... am I worrying for nothing or is it some of sign please advice...

    • By Mutswetsi (not verified) on 3 Dec 2019 - 12:14

      hi I have only two weeks pregnant but I experience difficulties in sleeping by both sides, what must I do??

    • By Melody Hall (not verified) on 30 Nov 2019 - 23:22

      I use to sleep on my left side bout i cant sleep so i sleep better on my right side

    • By Precious (not verified) on 20 Nov 2019 - 19:42

      I'm 24 weeks preg and I slept on my stomach for about 5 minutes and now it hurts what should I do?

    • By Kerrie cundill (not verified) on 27 Oct 2019 - 22:06

      Before getting pregnant I used to sleep on my belly I'm now 16 weeks pregnant and I've tried sleeping on my side but find I wake up a lot, and can't get comfy enough like I can on my belly but is it safe enough to sleep on my belly especially as I'm a big girl and I haven't yet started to get a bump at all

    • By Midwife @Tommys on 30 Oct 2019 - 12:46

      Hi Kerrie
      We do advise that you start sleeping on your side to try to get used to it as quickly as possible. We know that sleep can be disturbed in pregnancy and getting comfortable can be difficult, but sleeping on your bump, especially as your pregnancy progresses, will not be comfortable for baby or yourself and there can be associated risks as the pregnancy progresses. Tommy's Midwife

    • By Jennifer George (not verified) on 18 Oct 2019 - 13:54

      Hi I was diagnosed with a right side abdominal cyst that is quite painful .. And I am 10weeks pregnant, the last time in went for a scan, my baby was fine, I could hear that heartbeat from the ultrasound machine.. The doctor said everything is OK, but I am so worried about this pain I get constantly from the cyst .. I hope it won't affect my baby or my giving birth naturally. Will it ever go away?

    • By Christy (not verified) on 3 Sep 2019 - 11:30

      is it safe to stretch in bed when your eyes open up in the morning?
      the uncontrollable type of stretch where your body stiffs up?

    • By Kate (not verified) on 27 Mar 2019 - 14:25

      One of the research studies also showed a correlation between stillbirth and women who didn’t get up in the night to go to the loo or only got up once. Any further evidence to support this?

    • By Rebecca (not verified) on 16 Mar 2019 - 13:34

      Hi. I went for an appointment this morning and was lying on my back for 15 mins too (with head on pillow). I am currently going 24+ weeks and worried this would be bad for baby. Can I continue this going forward or would I need to be sat up?

    • By Tisha (not verified) on 20 Dec 2019 - 00:39

      I was told at my hospital appointments not to lie too flat down when being examined because the baby doesn't like it. So you can bring the bed up a little.

    • By Slf (not verified) on 16 Feb 2019 - 07:36

      Hi, I wondered if sleeping propped up on your back was okay? I’m trying to sleep on my side but find it uncomfortable sometimes. What angle would it need to be at?
      Also, when I’m sleeping on my side sometimes I’m angled back, leaning against a pillow - my bump is still pointing toward the side rather than up. Is this okay? I’m nearly 28 weeks. Thanks.

    • By Midwife @Tommys on 20 Feb 2019 - 15:03

      Hi Slf
      The problem with sleeping propped up with pillows, is the tendency that you will eventually slip down into an "on your back" position. Side sleeping is the only position that will allow for the best amount of blood flow to your baby. Being semi recumbent, laying angled back even, still constricts the blood vessel that we are trying to avoid constricting, although to a slightly lesser extent. Trying investing in or making our own pregnancy pillow - there are lots of YouTube videos on how to do this. All the best. Tommy's Midwife

    • By bhavna (not verified) on 22 Jan 2019 - 11:37

      We (me and my husband) both love and wait for daily updates and articles. We follow doctor’s advice videos and let me tell you some of videos helped us a lot. Seems this site is running by medical and caring professionals.

    • By Midwife @Tommys on 29 Jan 2019 - 11:09

      Hi Bhavna
      Thank you for your lovely feedback. We are glad to hear that you have found our articles and videos comforting and informative. Look after yourself, Tommy's Midwife

    • By Ami (not verified) on 13 Jan 2019 - 06:32

      Is it safe to lay down on your back while you’re awake?

    • By Midwife @Tommys on 15 Jan 2019 - 10:03

      Hi Ami,
      The research looked at going to sleep and adopting left or right sided position. If you are awake lying on your back the pressure of your bump on your major blood vessels will affect blood supply to you and your baby so even if you are planning to rest after 28 weeks do this whilst lying on your side. Lying flat on your back is not recommended after 16 weeks when exercising and often Mums aren't very comfortable in this position anyway.
      Hope this helps!
      For more information look go to this link
      Warm wishes
      Anna-Tommy's Midwife

    • By SF (not verified) on 20 Dec 2018 - 05:16

      Hi, I’m aware of the risks of sleeping on your back during the third trimester, but what about the second? I’m 19 weeks and finding it hard to stay on my side all night.

    • By Midwife @Tommys on 20 Dec 2018 - 16:35

      Try not to worry. As you know we advise all pregnant women to sleep on their side in the third trimester and for women in the second trimester to try to get used to this position. As your baby grows you will get used to the position as you will be less comfortable on your back.

    • By Katie (not verified) on 9 Dec 2018 - 10:14

      I'm 31+2 weeks pregnant and it's so uncomfortable for me to sleep on my sides, I can't get comfortable supporting my belly and no matter which side I sleep on I get sciatica pain and some times leg cramps. I've recently been going to sleep slightly propped up on my back and sleeping for about 5 hours straight each time, but starting to feel worried whether this is going to be safe to keep doing?

    • By Midwife @Tommys on 12 Dec 2018 - 16:01

      We discussed this last year when we launched the 'sleep on side' campaign and it was thought that sleeping propped up at an angle of 30 degrees would take the weight off the main blood vessels that supply the placenta. Hopefully you will also sleep well at this angle.

    • By Susanna (not verified) on 1 Dec 2018 - 12:43

      Hi, but was that proportion of back sleepers with still births also belonging to another group (eg overweight/ unfit) ? So going to sleep on the back alone would not be a risk, how many variables were controlled for ?

    • By Midwife @Tommys on 3 Dec 2018 - 15:50

      Hi Susanna, Yes this was a huge study done in the midlands and north of England (MiNESS) which confirmed results of studies done before in New Zealand. Body mass index, Babies small for gestational age and gestation were all accounted for. Naturally it would be very difficult to look at every variable but the results were conclusive and have shown that going to sleep on your back in the 3rd trimester is a risk factor on it's own.

    • By Stevie (not verified) on 20 Oct 2018 - 20:43

      I’m worried that laying on my side is gonna hurt my baby, like what if I squash his head with my weight or something?

    • By Midwife @Tommys on 23 Oct 2018 - 12:36

      If you are overweight it is all the more important to sleep on your side rather than on your back. Your baby is protected inside a fluid filled uterus and is unlikely to be squashed. Make sure that you exercise as much as you can and try to eat a healthy diet with at least 5 vegetables and fruit each day.

    • By chomba Judith (not verified) on 30 Jun 2018 - 00:57

      I always try to sleep on my side but some times when I woke up I find myself on my back. 8 months

    • By Midwife @Tommys on 2 Jul 2018 - 09:49

      Hi Chomba, Try not to worry about this. Just turn over onto your side again and go back to sleep. Take care

    • By Jennifer (not verified) on 20 Jun 2018 - 15:58

      How does this advice sit with the guidance from the NHS?

    • By Midwife @Tommys on 21 Jun 2018 - 16:58

      Hi Jennifer,
      The advice is the same as the NHS which is to avoid going to sleep on your back in the third trimester.
      Best wishes
      Tommy's midwife

    • By Lora (not verified) on 23 May 2018 - 02:41

      No matter what side I lay on I get really bad Indigestion Some nights I wake up with rib pain. Laying on my left side gives me lower back pain. 38+6

    • By Midwife @Tommys on 24 May 2018 - 11:32

      Hi Lora, Thank you for your comment.
      As you are now 38+6 and this pain is waking you up at night we would recommend that you call your local maternity unit so that you can have an antenatal check. Have your blood pressure checked and get a midwife to test your urine for protein. The reason for this is that pre-eclampsia can cause upper rib pain which is similar to indigestion. Please don't be alarmed as this could just be indigestion, however, as you are at the end of your pregnancy then it is important that you get this checked out. Hope this helps, take care, Tommy's Midwives x

    • By Anniesa (not verified) on 15 Mar 2018 - 14:29

      Even on my side I have shortness of breath what can help

    • By Midwife @Tommys on 15 Mar 2018 - 16:47

      I am unsure if you are experiencing this when just on your side or your shortness of breath is continuous. If this is on going then do speak with your midwife, as this can be a sign of low iron levels or rarely, something more serious. Best wishes, Tommy's midwives.

    • By Jass (not verified) on 12 Mar 2018 - 22:44

      Hi I’m 29 weeks pregnant
      Can I sleep on my right side . Is it safe

    • By Midwife @Tommys on 15 Mar 2018 - 12:08

      Hi, Thank you for you comment.

      It is safe to sleep on either your right of left side, as long as you fall asleep on your side then this is beneficial for you baby. Hope this helps, Take Care, Tommy's Midwives x

    • By Lola (not verified) on 20 Nov 2017 - 16:14

      As a physio I have treated many women with pelvic arthropathy and have often given advice regarding lying on side which has been to position pillows in an L shaped position at the front of the pelvis. This means that the uppermost leg should rest on the pillows giving support to the sacroiliac joint which is the cause of a lot of pain in pregnancy due to lax ligaments. When advising people to lie on their side it may be helpful to give advice on how to do it safely and with comfort which might aid compliance.

    • By Midwife @Tommys on 22 Nov 2017 - 09:17

      Hi Lola! That is brilliant feedback and very useful to our women- so thank you!

    • By Lisa (not verified) on 20 Nov 2017 - 16:08

      I'm 8 months pregnant and finding it difficult to sleep for the whole night on my sides. I have tried being on my back but propped up with some pillows and slept really well. Is this safe? How propped up do I need to be?

    • By Midwife @Tommys on 22 Nov 2017 - 09:16

      Hi Lisa.
      Congratulations on your pregnancy! I know it can be ever so tough in the third trimester to get comfortable in bed. It sounds as if you are changing positions - from side to side and more upright and this is perfectly safe. You will need to be fairly upright when propped up with pillows to ensure that you do not slip down into a flat - back position. Most women feel quite dizzy or breathless if they try to lay too flat on their back regardless, so try not to worry. Your frequent position changes (and likely trips to the loo) will ensure that you are unlikely to be in one position for too long anyway! Take care and please contact us again if you have any further questions.

    • By Nanette (not verified) on 20 Nov 2017 - 13:09

      Hi, I've been tending to lie on both sides as depending on what position each twin is in I can be more comfortable on right than left or vice versa.
      Is there any advice on twin pregnancies please? should I still aim for left side (mine have their own placentas, twin 1 head down, twin 2 moves & changes position regularly). Thank you

    • By Midwife @Tommys on 22 Nov 2017 - 09:11

      Hi Nanette.
      Congratulations on your twinnies! No, there should not be any difference between a single or twin pregnancy(although this was not a part of the research trials i must admit) . Laying on your side, left or right, means that the blood flow and oxygen is optimal to both babies. Keep up the awesome side sleeping mummy! And feel free to contact us again if you need more advice!

    • By Caroline (not verified) on 20 Nov 2017 - 11:53

      Presumably this advice applies to laying on our backs generally, and not just when sleeing? Bit of a ‘first world problem’ but for example things like beauty treatments (i’ve been lucky enough to have been bought some as a pre-baby pamper!) can mean you may be on your back for 1-2 hrs at a time. Would you recommend not doing this at all? Or is it safe olif we sit up every so often? And if so how often? Some more advice would be really appreciated as i’ve got in a bit of a oanic over it all and may end up cancleling everyhing at this rate! Thank you x

    • By Midwife @Tommys on 20 Nov 2017 - 11:57

      Hi Caroline. You can certainly go for your facial, but simply ask the beautician to sit you up on the massage bed/treatment bed. You do not need to be laying flat to have a facial or to enjoy having a facial. But yes, do not lay flat on your back for this treatment.

    • By Lola (not verified) on 20 Nov 2017 - 06:42

      As a physio I have treated many women with pelvic arthropathy and have often given advice regarding lying on side which has been to position pillows in an L shaped position at the front of the pelvis. This means that the uppermost leg should rest on the pillows giving support to the sacroiliac joint which is the cause of a lot of pain in pregnancy due to lax ligaments. When advising people to lie on their side it may be helpful to give advice on how to do it safely and with comfort which might aid compliance.

    • By Midwife @Tommys on 20 Nov 2017 - 10:20

      Many thanks for your feedback Lola! We do discuss the use of pillows too, to ensure that women are both safe and comfortable when settling down to sleep!
      On social media tomorrow, as part of the campaign, we are discussing practical tips on sleeping, focusing on the use of pillows and supports.

    • By Anonymous (not verified) on 13 Sep 2017 - 21:04

      **Tip** Im a natural back sleeper so tried lots of things during my 2 pregnancies, i found that tying my hair into a low bun almost always stopped me from rolling onto my back.

    • By Midwife @Tommys on 14 Sep 2017 - 14:59

      Hi, Thank you for sharing your helpful hint, different things can work of every women so it is great to hear about what worked for you in your pregnancy. Tommy's Midwives x

    • By Keely (not verified) on 12 Oct 2017 - 03:57

      I totally agree with this. I hate to lay on a bun!! Great tip!

    • By Midwife @Tommys on 12 Oct 2017 - 10:35

      Hi, Thank you for your comment.
      There are lots of helpful aids that can encourage safer sleep but if you start on your side before you go to sleep then this would be great position to start in sleeping pregnant women, avoid sleeping on the back during pregnancy. Hope this helps, best wishes. Take Care Tommy's Midwives x

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