Low-lying placenta (placenta praevia)

The placenta is your baby’s support system in the womb. If the placenta doesn’t work properly, your baby is at risk of health problems.

The placenta processes your baby’s nutrients, waste and oxygen. 

In most pregnancies the placenta attaches to the side of the womb but for some women the placenta attaches lower down and may cover a part or all of the cervix (entrance to the womb). This is called low-lying placenta or placenta praevia.

This often shows up in early ultrasound scans when it is called low-lying placenta. In 90% of cases, the placenta moves upwards as the womb grows. For some women, however, the placenta continues to lie in the lower part of the uterus after 20 weeks. This affects 1 in 200 births.

When this happens it is called placenta praevia. If the placenta covers the cervix, this is known as major placenta praevia.

A note on the difference between placenta praevia and anterior placenta

People sometimes think that low-lying placenta is linked to having an anterior placenta but this is not correct. Anterior placenta simply means the placenta is on the front (belly side) of the womb rather than attached to the back of the womb. Having an anterior placenta is normal and does not cause complications. 

How would I know if I had placenta praevia?

Placenta praevia is usually spotted during your normal ultrasound scans but other signs are:

  • painless vaginal bleeding in the second or third trimester
  • baby in an unusual position in the second or third trimester, breech for example or failure of the head to engage in the pelvis just before labour starts.

If you have any bleeding, contractions or pain in pregnancy you should always contact the hospital.

You may have a transvaginal scan (where the probe is placed inside the vagina) to confirm whether you have placenta praevia.

The risk factors for placenta praevia

In many cases the cause of placenta praevia is unknown but the following risk factors are associated with the condition:

Treatment for placenta praevia

You will have extra scans if you are found to have a low-lying placenta in a routine scan.

An extra scan is recommended at 32 weeks if:

  • you had a caesarean section before
  • your placenta covers the cervix (major placenta praevia)
  • your placenta is in an anterior position (at the front of the womb) and you have had a previous caesarean section.

If your placenta does not cover the cervix and you have no bleeding during your pregnancy, your extra scan should happen around 36 weeks instead. 

There is a risk that you may bleed in the second half of pregnancy (sometimes caused by having sex). Bleeding from placenta praevia can be heavy. If you bleed contact your hospital immediately.

If you have major placenta praevia (the placenta covers the cervix) you may need to stay in hospital after 34 weeks of pregnancy even if you have had no symptoms. There is a small risk that you could bleed suddenly and severely, which may mean that you need an urgent caesarean section. If you are bleeding the baby may need to be delivered.

Placenta praevia is linked to spontaneous preterm delivery and PPROM (waters breaking early), a major cause of premature labour.

The birth

Your obstetrician and / or midwife is likely recommend delivery in hospital, rather than a home setting, and caesarean section might be considered the safest option if the placenta is less than 2cm away from the internal os (the part of the cervix that opens into the uterus).

If you have major placenta praevia (where it covers the cervix) or if the placenta is very close to the cervix you will need to have a caesarean section because the placenta lies in the way of your baby being born.


  1. RCOG (2011) Information for you: A low-lying placenta (placenta praevia) after 20 weeks, Royal College of Obstetricians and Gynaecologists
  2. RCOG (2011) Placenta praevia, placenta praevia accreta and vasa praevia: diagnosis and management, Green-top Guideline No 27, Royal College of Obstetricians and Gynaecologists
  3. BMJ Best Practice (accessed Oct 2016) http://bestpractice.bmj.com/best-practice/monograph/667/diagnosis/history-and-examination.html
  4. BMJ Best Practice (accessed Oct 2016) http://bestpractice.bmj.com/best-practice/monograph/667/basics/aetiology.html
  5. J David, Steer P et al (2010) High risk pregnancy, management options, Elsevier Saunders
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    Last reviewed on September 12th, 2016. Next review date September 12th, 2019.

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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 Sian (not verified) on 6 Jul 2018 - 15:24


      I went for my anomaly scan at 19 weeks and was told I have a low lying placenta. They have booked another scan in for 34 weeks, what are the chances from now of this moving? If at 34 weeks it hasn't moved, will i have to stay in hospital until i have a c-section? This is my first pregnancy so abit worried.


    • By Midwife @Tommys on 9 Jul 2018 - 12:09

      Hi, At this stage there is no reason to be concerned. In 90% of these situations the placenta moves out of the way before the scan at 34 weeks. If you have any bleeding you should call your maternity unit straight away but in the absence of bleeding please try not to worry and continue with your normal lifestyle. Take care

    • By Anonymous (not verified) on 6 Jul 2018 - 11:22

      I have been told I have a low-lying placenta at my 20 weeks scan, I am now 24 weeks and wondering if I need bed rest

    • By Midwife @Tommys on 9 Jul 2018 - 12:02

      No, in most situations the placenta will move out of the way before the birth is due. If you have not had any bleeding there is no reason to change your lifestyle. You will have another scan at 34 weeks to check the placenta location again and if you do have any bleeding or concerns please contact your maternity department.

    • By Davinder (not verified) on 18 Jun 2018 - 13:10

      Hi I’m 32 week pregnant with low lying placenta last week I have some bleeding & clot I stay in hospital 3 days dr send me home yesterday start again bleeding & clotting not continue now I’m worried because I have 2 c section

    • By Midwife @Tommys on 21 Jun 2018 - 16:22

      Dear Davinder,
      I do hope that you have been back to the hospital if you are bleeding again. If your placenta is still low then you would need a c section, this is worrying you then do speak with your midwife about making a birth plan and if there is something in particular that you are worried about.
      Best wishes
      Tommy's midwife

    • By Jo (not verified) on 11 Jun 2018 - 19:21

      Hi, my placenta was posterior low at my 20 week scan and at 32 weeks is 17mm from the os so it’s moved up a bit. I have another scan booked for 36 weeks - just wondered if it’s likely to move any further or (as it’s been quite a slow process) it will remain below 20mm? Also, I’ve read that with a posterior placenta, C Sections are likely for placentas less than 30mm, so it could have even further to move! I’m frightened about having a C Section and am gutted I may not be having a vaginal birth :( Thank you

    • By Midwife @Tommys on 13 Jun 2018 - 11:14

      Hi Jo
      It's easiest for you to call us on the pregnancy line (0800 0147800) between 9 am and 5pm, Mon to Fri to talk this through in more detail.
      Placenta's can and do move, but there is a limit to how far they will move/grow up and away from the cervix if it's low lying.
      Your obstetric consultant is best placed to give you tailor made answers to your questions based on your own personal medical and obstetric history. But we are very happy to talk things through with you too! Speak to you soon
      Sophie, Tommy's Midwife

    • By Shaili (not verified) on 24 May 2018 - 12:57

      I found low lying placenta in 18 weeks of pregnancy, my doctor advised me for another scan in 32 weeks. But my placenta is still Low. Is there any chance that it will move upward or it is attached to the uterus. I'm worried about c section delivery.

    • By Midwife @Tommys on 24 May 2018 - 16:10

      Hi Shaili,
      Sorry to hear that you are so worried. Yes you would need a c section if your placenta is next to overlapping the cervix. The doctors should speak with you about this. If you do need a c section, we do have lots of information about this if this helps you to prepare: https://www.tommys.org/pregnancy-information/labour-birth/c-sections-everything-you-need-know
      Wishing you all the best.

    • By Sam (not verified) on 9 May 2018 - 14:39


      I am 16weeks pregnant I have had spotting throughout this pregnancy that started at about 6 weeks. This is my 7th pregnancy and 4th baby I have had 3 miscarriages one miscarriage I haemorrhaged and nearly died I was in HDU after miscarriage In my second pregnancy I had placenta previa grade 4 was in hospital a lot throughout pregnancy had an emergency c section at 35 weeks and I haemorrhaged. I have been told that my placenta is low lying reaching internal os. How likely is it that my placenta will me and is there a risk of me haemorrhaging? Very anxious and worried.

    • By Midwife @Tommys on 10 May 2018 - 15:45

      Hi Sam, I am sorry to hear that you have had some complicated experiences with your pregnancies!
      The person best placed to go through all of your concerns, is an obstetric consultant at your maternity unit. With your pregnancy notes- both for current and historical pregnancies, they can make a predication as to what may be a risk for you in this pregnancy, as well as make a plan of care for what may need to be done for you in this pregnancy. You can get a consultant appointment via your hospital antenatal clinic - you can also ask your midwife to get you an appointment to be seen.
      At 16 weeks, it is possible that your placenta will grow away from the cervical os, and therefore no longer cover it. However, this is not the case for every woman, hence why you will need input from an obstetric consultant to keep an eye on placental location, bleeding, birth method etc
      Good luck with everything and feel free to get in touch again if we can be of any further assistance to you.

    • By Sam (not verified) on 12 May 2018 - 08:37

      Thank you for your reply I have now been referred to a consultant at the local hospital x

    • By Maria brown (not verified) on 16 Apr 2018 - 12:15

      HI, I’m a neoNatal midwife so do have obstetric knowledge ..however , I’m pregnant with baby 3 ( previous non section surgery and infection in womb and two major p p h ‘s ) I had bleeding for 4 weeks from 6/40 .....then this Sat at work in the NICU i started fresh bleeding during my shift . Prior to this that week, I’d had excruciating back pain and tummy cramps . I got an abdo support from physio but I’m wary of wearing due to my placental position . It’s at or on cervix posterior not entirely sure if covering at all or completely but def low lying / previa . I had pelvic floor surgery 15 months ago and. A weak pf anyway could this be attributed to the pressure down below and on my back ? I literally can’t be on my feet for more than half an hour as it kills ...so work is probably not advisable as do nights and long 13 hr shifts ...drs day they’d like me to get to 32/34 weeks but the pressure down there is intense - do u think this is due to pp or just the pregn or a weak pf ? The bleeding has settled but I’m wary of it re starting esp as 21 weeks only ...thanku

    • By Midwife @Tommys on 19 Apr 2018 - 10:21

      Hi, Thank you for your comment.

      At 21 weeks a low lying placenta does have time as the pregnancy progresses to move up and out of the way of the os ( exit to the womb ) you should have another scan around 34 weeks to check the position of your placenta.
      With regards to this pressure feeling you are experiencing, this could be due to the fact that your pelvic floor does have some weakness in it and this is your 3rd baby. Do you have any pain when urinating or are you going more often as this may be due to a urine infection. If this is becoming very painful for you then is may be advisable that you speak to your midwife or GP about getting a women's physiotherapy session, they should be able to give you some strengthening exercises that may help with the pressure.
      As you are aware, if you have any further bleeding or abdominal pain then please contact your local maternity unit so that they can assess you. Hope this helps, good luck in your pregnancy, Take Care, Tommy's Midwives x

    • By Rachel (not verified) on 23 Mar 2018 - 20:00

      I was told I had a low lying placenta at 20 weeks, and would need a c section if it didn't move due to proximity to os. I was scanned again at 31w and it hadn't moved at all. I have another scan at 34w then 36+6. If it hasn't moved at all yet what are the chances it will now?

    • By Midwife @Tommys on 26 Mar 2018 - 10:30

      Hi Rachel, The chances of it moving away from the os are decreasing certainly. If it is located less than 2cm away by the 36 week scan you will be advised to have a caesarean section. If you have any bleeding you should be ready to go to hospital immediately.

    • By Amaka Victor En... (not verified) on 17 Mar 2018 - 13:57

      Hi i went to scan today iam 27 weeks i was told i have low lying placenta.What are the chances of it moving up at 32weeks.

    • By Midwife @Tommys on 19 Mar 2018 - 15:54

      Hi Amaka
      As the uterus grows, the placenta often moves away from the opening of the uterus. We don't have statistics for this but if the placenta is more than 2cm away from the cervix at delivery a normal delivery is usually recommended. If you have any bleeding it is important that you are seen straight away to exclude any problems with the placenta separating. You will be advised at 32 weeks if the placenta is still low. Best wishes

    • By Anonymous (not verified) on 16 Mar 2018 - 22:22

      Hi I am currently 28 weeks pregnant and have a low lying placenta with a lot of pain just above my pubic home where the baby's head is and also keep getting bleeds not really heavy though and hospital keeps telling me I'm fine as they can't find where the bleeding is from is this normal? Also what are the chances of me needing a cesarean as the my baby is also measuring about a month behind on growth aswell.

    • By Midwife @Tommys on 19 Mar 2018 - 14:20

      Hi, It is important that you go to get checked each time you have a bleed. It isn't always possible to see where the bleeding is coming from but your midwife or doctor will be able to check the baby and ensure that the bleed has stopped before you go home again. A scan will be able to confirm how close your placenta is to the cervix (the opening of the womb) and this will determine whether or not you will need a caesarean section.

    • By Amaka Victor En... (not verified) on 14 Mar 2018 - 15:25

      Hi i went to scan today iam 27 weeks i was told i have low lying placenta.What are the chances of it moving up at 32weeks.

    • By Midwife @Tommys on 15 Mar 2018 - 16:30

      There is about a 90% chance that your placenta will move up enough away from the cervix. If you have had a caesarean section before then the chance is about 50%. They will scan you again to see where your placenta is. If you get any bleeding then call your maternity unit straight away. If the placenta does not move then they will talk to you about the safest way to deliver your baby. Best wishes, Tommy's midwives.

    • By Midwife @Tommys on 1 Mar 2018 - 15:37

      It is completely understandable that you are feeling anxious in this pregnancy following your miscarriage. It is great to hear that you are now 14 weeks. Please do not worry about having a low lying placenta, this is quite common and for about 90%, your placenta will move up with the uterus as it stretches and away from your cervix. If you have had a caesarean section before then this is reduced to about 50%. However having a low lying placenta does not cause miscarriage and is not a risk to your baby. If you do have any bleeding then do call your midwife or maternity unit to be reviewed.
      Best wishes, Tommy's midwives x

    • By Stevie (not verified) on 27 Feb 2018 - 14:11

      Hi am nearly 33 weeks pregnant with my 7th child. I have a low line placenta and have scans every 2 weeks on both last scans baby boy was breech. Am have beLlysfaen tightenings and I have a constant pain in the top of my belly. No bleeding tho. I just don't no what to do a don't want to waste people's times but as I had a still birth 2 years ago am so frightened. Any info or advise wud be great

    • By Midwife @Tommys on 28 Feb 2018 - 12:18

      Hi Stevie
      Any abdominal pain, at any gestation of pregnancy needs to be reviewed urgently. So if you have not already done so, please do go into your maternity unit triage/labour ward asap with your notes to be seen. You are not wasting anyone's time! It sounds as if your care is very good with your regular scans etc, but please do go in asap today to get reviewed if you have not been in since you sent this message!
      Please take good care of yourself,
      Sophie,Tommy's Midwife

    • By Sumbile (not verified) on 6 Jan 2018 - 08:03


      I am 17 weeks pregnant with twins. I have been bleeding on and off for one week now with clot. Although no pain or cramp. My doctor ordered a scan and both babies are doing well. The doctor said the placenta is down. Although i have done cervical carlage at 14 weeks. The doctor has ordered bed rest for 2 days now which made d blood reduce however i took a few steps and saw bleeding again. Really in a confussed state of mind. Any advise to calm me. This is my first pregrancy althrough it was an ivf procedure

    • By Midwife @Tommys on 10 Jan 2018 - 10:18

      Hi Sumbile
      For your peace of mind, i would recommend going back to the hospital to see a midwife/doctor again asap. As this bleeding has suddenly increased again, it is worth being reviewed again, just in case things have changed in any way at all.
      Any bleeding from the vagina, at any gestation of pregnancy, needs to be investigated urgently. Please take good care of yourself.
      Sophie,Tommy's Midwife

    • By Brook38 (not verified) on 24 Dec 2017 - 10:11

      Hi there

      I’m 33 weeks pregnant and have placenta praevia. It’s partially covering the os. I spent a week in hospital last week as I had a couple of small bleeds followed by one quite significant one. I was discharged from hospital and told to take it easy, stay home and come straight back to hospital if I have any bleeding.

      I was wondering if it’s ok for me to continue with pelvic floor exercises? I’ve been told to be on pelvic rest (ie no sex) but didn’t think to ask about pelvic floor exercises when I was speaking to the doctors.

      Thanks for your help.

      By the way, i found your website really helpful when we thought we were going to be needing an early emergency c section last week.

    • By Midwife @Tommys on 3 Jan 2018 - 10:59

      Hi Brooke. Thank you for getting in touch. I do apologize for the delay- we close for Xmas from Fri 22nd Dec 2017 - Tues 2nd Jan 2018.
      I would advise you to avoid any activity, including pelvic floor exercises if you have had so many bleeding episodes. It is unlikely to cause any harm, as your muscles of your perineum are not attached to your cervix, but still, it might be best to avoid them.
      I really hope that things are ok with you and baby. Please feel free to call or email us if you need any further help or support!
      Sophie,Tommy's Midwife

    • By Anonymous (not verified) on 25 Nov 2017 - 14:07

      Hi, I am 17weeks pregnant and I had some bleeding last Saturday when I passed urine early in the morning and that is when I visited my doctor who has suggested for an ultrasound scan and that showed I've a low lying placenta of 1.4cm. I didn't have any bleeding from the next day. My doc advised bed rest for a couple of weeks. This is my first baby and I am really worried about any risks that can happen to my baby. Can you let me know since there's no bleeding, the placenta might have moved up and that it didn't cause any harm to the baby.
      Also could you please mention a few points about how can I be careful to avoid bleeding during my pregnancy.
      Can I continue to go to work as usual.
      Thank you in advance.

    • By Midwife @Tommys on 27 Nov 2017 - 10:28

      Hi. You have already done the right thing in that you saw your doctor as soon as you had bleeding. You will have additional scans for the rest of the pregnancy to see if the placenta remains over or close to the cervix. This is a slow process and it will still be in roughly the same position that it was a week ago. Bleeding therefore remains a risk for you. Bed rest is the best advice but if this isn't possible, try to avoid strenuous exercise. Discuss with your doctor about work. This will depend on the sort of work you do. Please keep your handheld notes with you at all times and if you have any more bleeding seek medical advice immediately. It is too soon to make a plan for your delivery and this will be discussed with you later in the pregnancy. Best wishes

    • By Anonymous (not verified) on 12 Nov 2017 - 04:26

      I am 32 weeks with complete placenta previa. Does this mean that all babies will be born prematurely? Or can i still go to 38 weeks without complications

    • By Midwife @Tommys on 13 Nov 2017 - 15:38

      Have you just had a scan at 32 weeks to confirm complete placenta previa?
      Yes the pregnancy could go to 38 weeks but it is very common in this scenario for the baby to be born before this. I would expect that you will have another scan at 36 weeks. If you have any bleeding before this, please go to hospital straight away.
      If you have complete (or major) placenta previa your baby will be born by caesarean section. This should be explained to you in detail. If you are confused please call us on 0800 0147 800, or talk to your midwife again so that you are confident and know what to do. Best wishes Tommy's midwives

    • By Anonymous (not verified) on 28 Feb 2018 - 17:40

      I am 34 weeks pregnant now..i did my scan on 33rd week and its shown am having major placenta previa..placenta covers the cervix completely ..but till now Alhamdulillah there is no bleeding.. my doctor said it ll be c section... but will it be before 37 week ?

    • By Midwife @Tommys on 1 Mar 2018 - 15:41

      It is great to hear that you are not having any bleeding, if this continues to be the case then they will do your C/S after 37 weeks, as this is when your baby is term and lungs have the most time to develop. If you were to start bleeding or there were any other concerns then they would do it before this time but only if necessary.
      Best wishes, Tommy's midwives x

    • By First time mum ... (not verified) on 17 Nov 2017 - 19:24


      Am I correct in understanding that my diagnoses of low lying placenta or as written on my report 'low posterior placenta' is the same as 'placenta previa' (just a different name?).

      I am concerned that I have been told I have this (at scan this week 33 wks +2)with it being 10mm from the internal os but have had no advice about pain/bleeding. I had bleeding at 8 weeks, none since but had pain a few days ago on my left side. A stick type pain, enough to make standing up and movement very uncomfortable for about an hour. Should I be concerned?
      Also what may be the recommendation for distance required from cervix for natural birth in my case and what are the chances of it moving by my next scan in 3 weeks time?
      I have read that some Obstetricians prefer a larger distance of 3cm when placenta is posterior, is this correct?


    • By Midwife @Tommys on 20 Nov 2017 - 09:24

      Hi First time mum.
      Yes, this diagnosis is placenta praevia. There are many varying degrees of this, depending how close to the cervix the placenta is. If you have any bleeding, of any amount, or you are concerned about anything from fetal movements, to abdominal pain of any type etc, then please have very low threshold for taking yourself into the labour ward/day assessment unit/triage to review urgently reviewed by a midwife and obstetric doctor.
      I have posted to link to our entire page on placenta previa which will help answer all of your questions. Please do also feel free to call us on the pregnancyline (08000147800) if you wish to speak to a midwife in more detail about this.
      Take care of yourself :)

    • By Anonymous (not verified) on 18 Aug 2017 - 23:53

      I've just had my anomaly scan. I am 19 weeks pregnant. The reault says my placenta is on the right, but lying low. The sonographer talked about a distance of 23 mm and called me borderline. She recommended a new scan wit 32 weeks to check the placenta's position, but said I had nothing to worry about. I still have a month before my next antenatal appointment... I've been having sex and doing pregnancy pilates classes during my pregnancy. I have no pain at all and no bleeding so far. Should I take any precaution? Plus, I have a long haul flight scheduled for week 21.. Should I change my plans?

    • By Midwife @Tommys on 21 Aug 2017 - 16:25

      I can understand that this would have worried you but in the absence of any bleeding if the sonographer has said nothing to worry about I would not change your plans. In 90% of women with a low placenta at 19 weeks it will have moved up and out of the way by 32 weeks.

    • By Anonymous (not verified) on 2 Nov 2017 - 13:59

      Hello how are you

    • By Midwife @Tommys on 2 Nov 2017 - 14:16

      Hi, The Tommy's midwives are very well Thank you.
      Hope you are also well. Please contact us if you need any help or advice.
      Take Care Tommy's Midwives x

    • By Midwife @Tommys on 2 Mar 2017 - 12:34

      Hi, thanks for your comment.
      I hope that the bleeding has settled down. Miscarriage is, sadly, fairly common. A quarter of women have experienced a miscarriage in their lifetime. As you are now 14 weeks, this would be called a late miscarriage and these are less common than earlier miscarriage before 12 weeks
      If you do experience further pain and bleeding please contact your local A&E or Early Pregnancy Unit for further assessment

      In most pregnancies the placenta attaches to the side of the womb but for some women the placenta attaches lower down and may cover a part or all of the cervix (entrance to the womb). This is called low-lying placenta or placenta praevia.

      This often shows up in early ultrasound scans when it is called low-lying placenta. In 90% of cases, the placenta moves upwards as the womb grows. For some women, however, the placenta continues to lie in the lower part of the uterus after 20 weeks. This affects 1 in 200 births.

      I have attached links to Tommy's website that may be helpful




    • By Anonymous (not verified) on 1 Mar 2017 - 14:09

      am 14 weeks pregnant and diagnosed with a low lying anterior placenta after I had slight spotting at 12 week. at 10th week my placenta was posteriorly formed.i had a miscarriage two years ago.so I am very much scared now.is there any chance of miscarriage again? And is there any other risks?

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