Low-Lying Placenta and Placenta Praevia

UK Midwifery Archives


These archives contain extracts from discussions held on the UK Midwives and Consumers email list, a discussion group for people interested in midwifery in the UK. Open to midwives, students, mothers, and anyone interested in improving maternity services in UK. Posts in these archives express the views of the individual authors, and not those of the Association of Radical Midwives.


Placenta Praevia and Low-Lying Placenta

Could anyone please give some information on the appropriateness of this advice.

A woman I know has placenta previa, was booked for a home birth. Has had some spotting. Placenta is 4.5 cm away from the os, anterior. She saw consultant today who wasn’t too bothered. Don’t want her to go too overdue, was 42 weeks with previous preg. This baby is fully engaged now, she is about 36 weeks. She’s been advised to have an epidural inserted from outset, so if the baby needs to be born quickly they can use forceps/ventouse without having to worry about pain relief. Is this standard practice? Is it a good idea? She feels quite happy as thought she’d be told she needed a section.

Tikki


A placenta 4.5 cms away from the internal os wouldn’t worry me too much, and I would be prepared to care for such a case at home. Though of course I would take into account the geography of the home. If she was within twenty minutes or so of a decent obstetric unit I would be happy.

In the unlikely event of undue bleeding as the lower segment dilates in the 1st stage of labour I would transfer by fast ambulance or paramedic ambulance and I would put a drip up while waiting for the ambulance. Bleeding can happen if there is a biggish vessel torn as the fringe of the placenta separates a bit, and is just bad luck. The baby is usually OK as it is not much of the placenta that has separated – the bleeding is just because of a ruptured a vessel. The bleeding will usually stop as the head comes down with the contractions, giving one time to transfer.

I think advising an epidural is a bit over the top in such a case. If the placental fringe was nearer the os perhaps it could be considered, but 4.5 cm from the os at 36 weeks is not really a serious degree of placenta praevia. Though, as I said, it could bleed and one should be prepared.

Mary Cronk
Independent Midwife


I had a grade II then grade I placenta praevia with Rose (presenting twin). I wanted a vaginal birth so I sought info to enable me to achieve this. I found the book ‘Having twins’ by Elisabeth Nobel very supportive of vaginal birth with a low lying placenta, and even with a marginal placed placenta. Even though this is a twin book, her points remain valid for singleton births too. The spotting usually occurs at 28-32 weeks when the lower segment starts to stretch. Not all get this, and hers may have also been incidental to the low-lying placenta.

From what I read a low-lying placenta isn’t a precursor to placental failure or abruption; I’m guessing that’s your concern if she goes post-term. But what I did learn was the lower segment isn’t as vascular as the upper; I don’t know if this effects placental blood flow or not. Also the circular configuration of the muscle fibers in the lower segment aren’t as efficient at ligating blood vessels after placental separation. This doesn’t mean she will haemorrhage, but it is something to be aware of.

On the same lines, towards the end of pregnancy and during labour when the lower segment is drawing up she may get a little bleeding, but again this isn’t a given, and I never experienced this either. The fact she has had no bleeding episodes ( aside from spotting) is not being pulled in by the obstetricians for early delivery, and has the option of going post term, would suggest her praevia isn’t to serious. One other thing I read is that there is a ‘slight’ incidence of placental accreta, especially if she has had a previous caesarean section. If that happens and they cannot stop the bleeding she may end up with a hysterectomy.

Because your friend’s low lying placenta is anterior, a caesarean section would be difficult as they would need to make the incision over the placenta. This was the case for a friend of mine who had her praevia at the same time as me. They preformed a classical incision on her as vaginal birth was not possible in this situation. The fact her baby is fully engaged indicates that birthing the baby vaginaly will not be a problem.

Regarding the epidural, the baby will only need to be born quickly if her placenta abrupts during labour, in which case she is likely to be given a general anaesthetic anyway. I would be a little concerned about setting an epidural up from the onset as they do slow labour and contractions down considerably, and if she has this in the early stages it may set her up for other interventions such as a syntometrine drip, which you do not want if you’re trying avoiding an abrupted placenta! I haven’t seen any studies on it, but I think epidural anesthesia may make you more likely to bleed post-partum because of how it slows labour contractions down; it’s just a theory but it might have the same effect on the uterine muscle post-birth, hindering it contracting.

In saying all that I myself had an epidural put in at 9cm, not for pain relief but for petrifying fear of an internal version. I had a light epi and was still able to walk, squat, go to the toilet and push ( with full feeling and effect). I’m not sure if this type of epidural would be appropriate for an instrumental delivery – certainly not a C/section, which is their reasons for administration. She may unfortunately be given the paralysing one which would prevent her from being mobile and brings with it a whole new set of complications.

Andrea, Mum of 9


My friend has been diagnosed by scan at 38 weeks with placenta praevia grade I – II . No bleeding or spotting – only indication was baby with unstable lie -taking homoeopathy for this.

Booked for home birth – wondering now if even vaginal birth is a possibility.

Any experience with this, please?

Monica O’Connor
Home Birth Association of Ireland
 http://www.iol.ie/~hba hba@iol.ie

Grades of Placenta Praevia

Vaginal birth certainly a possibility: 
Type 1 most of placenta in upper segment, shouldn’t cause a problem
Type 2 some of placenta near internal os, vaginal birth possible.

Susie


From(Chamberlain G, Hamilton-Fairley D (1999) Obstetrics and Gynaecology : lecture notes on. Blacwell Science: Oxford):

Grade I The placenta reaches the lower segment but not the internal os
Grade II The placenta reaches the internal os but does not cover it
Grade III The placenta covers the internal os before dilatation but not when dilated
Grade IV The placenta completely covers the internal os of the cervix even when dilated

The book then goes on to say:

- Grade III and IV should have a Caesarean section between 37 and 38 weeks gestation
- If the presenting part is below the lower edge of the placenta in Grade I, then it is safe to wait until labour and these women can be expected to deliver vaginally (please note these are the words in the book, not mine)
- It does not say anything about Grade II !

It goes on saying (regarding possible risks) Maternal: Death from placenta praevia in the developed world is now extremely rare. The major cause of death in women with placenta praevia now is postpartum haemorrhage (PPH), PPH is common because the lower-segment does not contract and retract as in the upper segment, and therefore maternal vessels of the placental bed may continue to bleed after delivery. Fetal Bleeding from placenta praevia is maternal in origin. The risk to the fetus is therefore mostly dependent upon the gestation at which it becomes necessary to deliver the baby.

Jo


Remembering I come from a tertiary based hospital perspective…….. I would think homebirth would be an option if there was a backup hospital facility within close distance. And dare I say it, this might be a situation where prophylactic oxtocic might be a good idea.

Kirsten


As a midwife I have no experience of this as far as homebirth is concerned. If this was me, I would aim for a vaginal delivery and ask my homebirth midwife to care for me in hospital. I’d make it clear that when all goes well I want to go straight home from labour ward. The third stage really holds the maternal risks as far as the labour is concerned, even for women without a low lying placenta. If your friend was under my care I would recommend a hospital birth, treating everything as normal until a problem arose.

Susie


Update

My friend had her baby at 6 days past her due date, NORMAL, moved home and midwife, had a home-away-from-home birth – no trace of PPH – in fact, they had to wait 4 hrs. for the placenta to deliver – baby was 10 lbs – all doing well, despite the home upheaval.

Monica


AH updated 19 April 2001


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