Following conception, the placenta implants itself somewhere in your uterus, in no specific position. It may choose to implant low, high, posterior (back) or anterior (front).
After an ultrasound — usually the 20 week scan — you may be told that you have a low lying placenta, meaning the placenta has implanted low down in your uterus, close to your cervix. This is reported in around 5% of pregnancies. There is absolutely no need to worry if you are amongst this 5% – you can continue your daily activities as per normal unless you have been advised otherwise. Usually restrictions like no sex or lifting etc are prescribed to women who have placenta previa (placenta covering their cervix) and or those who experience blood loss due to a low lying placenta. But rest assured, as you doctor may tell you, there is a very high chance that a low lying placenta will be higher at a later scan.
In your third trimester (until around 36 weeks) the bottom part of your uterus does most of it’s growing and stretching, taking the placenta with it. It doesn’t ‘migrate’ upwards, but being attached to the uterine wall, it’s carried upwards with it. In 0.5% of cases, the placenta doesn’t move up with the uterus – so given that small percent, there is an extremely good chance that your placenta will not be covering your cervix when it’s time to give birth, enabling you to have a vaginal birth.
If you have a low lying placenta at 18-20 weeks, this does not mean you need a caesarean section. The placenta will highly likely be further away from the cervix at the end of your pregnancy. In your first and second trimesters, the uterus still has much growing to do, so an ultrasound late in your third trimester (after the uterus has finished growing) will give you and your doctor or midwife a better picture of what’s really going on – and if it really a matter of concern.
How Close To The Cervix Can My Placenta Be?
Doctors have different limits for how low they are happy for the placenta to be before they will tell you that you shouldn’t have a vaginal birth. It can be useful to get second/third opinions on a low placenta if you would like to avoid a caesarean section. Some doctors will be happy with the placenta to be above 2cms (20mm) from the os (cervix) and some prefer 3cms (30mm). Given the variation from doctor to doctor in measurements, if you want a chance to birth vaginally, you most definitely should be given the opportunity, unless the cervix is covered by the placenta and/or there are concerns due to bleeding – in which case you should seek medical advice immediately.
A birth client of mine had a low lying placenta (she was birthing in a large Melbourne public hospital) and her experience was that depending on which of the rotating obstetricians she saw in the check-up appointments, they would be happy for her (or not) to give vaginal birth a go, depending on their opinion of what was safe. This is no way to enjoy your pregnancy, worrying about who you’re going to get and if they are going to trust your body to give labour a go or not. Try to find out what distance the placenta is from the cervix and ask your doctor or midwife if they would be willing to support your wishes for a vaginal birth (should it not move, as well as what measurement they want it to be). If they wont support you, you may like to seek a second opinion from another doctor.
“My placenta was low lying (15mm or 1.5cms) at 20 weeks. Repeat scan at 27 weeks showed that it had moved to 40mm (4cms) and at the birth it became retained. I had to have it manually removed under a general anaesthetic – it had moved all the way up and became stuck in the fundus of my uterus!” — Amy, BB Member
Giving Birth After Previous Low Lying Placenta
If you’ve had a low lying placenta in previous pregnancies, it doesn’t mean it will happen again. The placenta does just attach itself where it pleases and in some cases its just bad luck.
“I had a low lying placenta with my first bub. But my second, third, fourth and fifth have been fine – PHEW!” — Linda, BB Member
Low Lying Placentas Resulting In Intervention
Here are some members stories about low lying placenta that needed medical assistance. If you experience vaginal bleeding at any point in your pregnancy, especially if you have a diagnosed low lying placenta or placenta previa, you should seek medical advice immediately.
Kitty’s Low Lying Placenta Story
“At 20 weeks I was told the placenta was adjacent to my cervix and not to worry, as 99% of cases sort themselves out. At 28 weeks I had bleeding. A scan at hospital revealed the placenta partially covering the cervix, not sure how much though. I was given two steroid shots, sent home after a week in hospital on bed rest. I was told no sex, no being more than 30 mins from hospital in case of haemorrhaging, no picking up anything heavier than what I could pick up in one hand, no walking long distances and no going anywhere by myself just in case.
At 32 weeks I was bleeding again. I had a scan at hospital but I wasn’t told whether it was worse than the 28 week scan. I was given another steroid shot and was supposed to have another scan 36 weeks to check where placenta was and make the decision on the birth plan. I was sent home after about 4-5 days in hospital again on bed rest. Was still bleeding slightly over the weekend so went back to hospital on the Monday at 33+6 weeks. They did a vaginal examination and I was kept in hospital for monitoring.
I was 34 weeks on the Tuesday and had a large bleed with a clot about the size of a peach, resulting in an emergency caesarean section.”
Jennifer13’s Low Lying Placenta Story
“My low lying placenta was picked up at both the 12 and 18 week scans. Was never over the cervix, just close. I had no bleeding and didn’t need to take any precautions. The scan at 37 weeks showed that the placenta was still low, but not over. It was about 1.7cm from cervix when the obstetrician wanted it to be 2cms away. I was advised to have an elective caesarean at 39 weeks. I tried to research outcomes for labour with that proximity to cervix, with not much luck and my obstetrician was a bit dismissive of my efforts to look into it further. I had the caesarean at 39 weeks.
BUT in hindsight and after much research, I think I should have sought a second opinion. With no bleeding and a baby that had engaged, I believe I would have been fine for a vaginal birth. At the very least, even my obstetrician acknowledged I would have been okay to go into labour and go from there. There would have only been the need to keep a close eye on how things progressed. Allowing labour to start naturally would have been beneficial for my tiny 2.5 kg baby too. She could have done with the extra week or so on the inside, plus the hormones that kickstart birth.
With no complications at all, I think I was given overly cautious advice and a probably an unnecessary caesarean. I have since found very similar cases online that did manage to have vaginal births without undue complications (some extra blood loss seemed to be the extent). Mine was not a previa and should not have been treated as such. Plus, that extra 3mm was not that unlikely if I’d stayed pregnant until 40 weeks. I had a very small baby and uterus and I think this impacted the growth/movement.”
Low Lying Placentas Requiring No Intervention
In a vast majority of cases, low lying placenta resolves itself and is nothing to worry about. Here are some member stories on their low lying placentas and needing no further intervention.
Pholi’s Low Lying Placenta Story
“At the 20 week scan it was picked up that the placenta was 2cm from cervix. I was told it was borderline, that there was a 95% chance it would have ‘moved away’ by the time of my baby’s birth (except they explained that the placenta doesn’t move, but as the uterus grows the edge of the placenta becomes less close to the cervix) and that I should still be hoping for a vaginal birth from that point of view. Was booked for a re-scan at 34 weeks. At 34 weeks it was confirmed to be well out of the way of the cervix, but I was not given a measurement, just assured that it was completely fine. The obstetrician reiterated that the position was no obstacle to my goal of a vaginal birth. I birthed my baby vaginally, with vacuum assistance, at 40+5. No complications to do with placental position.”
Taurean’s Low Lying Placenta Story
“I found out I had a low lying placenta at the 20 week scan, so another scan was booked for 32 weeks. At 32 weeks the placenta had moved a lot – around 7cm for memory. It continued to move. I went into spontaneous labour at 38+5, waters broke around 7.30am at home and my daughter was born at 3.10pm. I had no issues at all with my next birth.”
The Flying Butter’s Low Lying Placenta Story
“My low lying placenta partially covering the cervix was picked up at the 18 week scan. I was told it would probably move and not to worry. No-one said anything at the 20 week scan, so I figured it had moved by then. No-one said anything at a 30 week scan either. The placenta did not affect birthing at all.”
Meg’s Low Lying Placenta Story
“I had a low lying placenta in my 4th pregnancy – it was picked up at 13 weeks due to bleeding. Because of the bleeding, I was told to reduce heavy lifting. It was confirmed at the 20 week scan that the placenta was 2cm from my cervix and I was told that it should most likely move out of the way. Had another scan at 28 weeks and the placenta was well out of way, I think 8cm. Birthed vaginally at 40 weeks, no complications.”
What If My Placenta Is Covering The Cervix?
Placenta previa — which means placenta first — is a rare condition which occurs in around 0.5% of pregnancies. So although it does happen, the chances of this are quite low. Instead of implanting on the uterine wall, the placenta implants partly or wholly over the cervix. For more information, check out our article on placenta previa.