This article contains posts and extracts from 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. Unless otherwise stated, the comments are personal experiences rather than evidence-based research.

Artificial Rupture of Membranes – Breaking the Waters

Why is it done?

What exactly is the purpose of ARM (Artificial Rupture of Membranes)? Is it just to speed up birth- in which case who exactly does it benefit? Is it potentially dangerous? I’ve always pondered why this was done to me with my first baby – I never consented but that another argument! All I can remember was agony and losing control of the pain after it was performed.


Unfortunately artifical rupture of of membranes has become “routine practice”. It is useful if there is delay in progress. But it really has no place in nomally progressing labour. Very often the membranes will rupture just before birth. In the animal kingdom the offspring are very often born in their amniotic sacs.


I still don’t know of any reason to rupture membranes. The research indicated that it does not shorten labour by any significant amount. It is a method of inducing labour but that is another story.

Having said that I did rupture membranes last week – it was a first twin and when we had a grapefruit-sized bag of membranes hanging out and I could feel the head at the vulva I did rupture them with a hook. They were pretty tough and I wasn’t sure that I could wipe them off the baby’s face. In retrospect I could have let the baby be born in the caul. The second twin’s membranes ruptured as the breech was at the vulva.

Mary Cronk

The reason often given for performing an ARM is to speed up labour but if I remember rightly it only shortens labour by about an hour but it does tend to increase pain as the baby’s head is now directly on the cervix. This can lead to need for more pain relief and possibly more interventions.

Another reason is to check the colour of the liquor (amniotic fluid) if there are signs of distress, or to apply a fetal scalp electrode.


In my (limited) experience, ARM usually benefits the midwife. It speeds things up for her, and also gives her peace of mind as she can see whether or not there is meconium in the liquor so she can get a paediatrician ready to be present at delivery. There is no indication for it in normal labour.

We recently had a midwife in giving a talk about home birth and leaving the membranes intact. After the lecture, one of the students in my group was horrifed that a midwife would not perform ARM as it was so dangerous not to know if there was meconium! A few of us had a chat with her….


I had a birth the other night, woman having her second baby, contracting strongly when I took over. She was 4cm dilated, membranes intact on vaginal exam one hour previously, fetal heart was fine. She birthed her baby 20 minutes after I took over, baby born in the caul.

As the membranes bulged through the introitus I could see meconium so the resusitaire was brought into room and the paediatrician called for. I ruptured the membranes with the suction on the perineum so I could clear the nose and mouth.

If the membrane had been artificially ruptured previously she would have ended up with a different birth story (continuous monitoring, possible augmentation etc). As it was she birthed her baby in a quiet environment without being rushed. The baby’s heart rate was fine so there was no need to interfere.


When my son was born my waters didn’t break at all. The midwife finally broke them immediately before his head emerged. He was a bit stressed during labour – his heart rate was dropping lower than normal during contractions, but apparently recovering well. When she did break them there was some fresh meconium, which was expected. Was this why she broke them? Was he more likely to inhale it?

You say that your membranes did not rupture spontaneously and the midwife artificially broke them just before his head emerged. This is good practice – the intact membranes ensure that the pressures within the intact sac are equal, and thus protect the baby.

You do not mention the gestation; post “term” meconium in the liquor becomes much more common. Pre-term it can be an indication of distress. In my opinion if the membranes had been artificially ruptured earlier your baby might well have been even more distressed than he was. If there is concern about a baby and the membranes are intact, the last thing one should do is rupture them until the head is on the perineum and birth is imminent. I NEVER rupture membranes in a spontaneously progressing labour.

Mary Cronk

Ok, hand up, I did one last night because FH (foetal heart) was doing very strange things, probably due to speed of labour, though there was meconium there. Who doesn’t do ARMs for foetal heart rate irregularities? It wasn’t done until we’d had an hour of this, of early decelerations and a real drop in baseline, at one stage unfindable(!). If she’d been 10cm I wouldn’t have done it because this woman was labouring so well that once she pushed this baby flew out, but she was 8cm. What do you do if you don’t, what situations do you do them in??? Ever feel that the more experience you have the harder this job becomes?


I’ve been hoping list folk would contribute their experiences about carrying out Artificial Rupture of the Membranes in labour. I’ve only done one ARM for fetal bradycardia, to apply a fetal scalp electrode….which made the fetus relatively tachycardic for the next 20 min. (so the obstetric registrar was happy), but I can’t really figure out what good it did for the labour (Primigravida, nearing transition stage….)

If the mother is in hospital, and a paediatrician can/will be called to be present at the delivery (if the midwife continues to be concerned)…does the midwife really want to know if there is meconium in the amniotic fluid?? Or is an ARM pure and simple augmentation of labour??

I keep wondering about this, as I’ve seen the FH drop drastically following SROM (spontaneous rupture of membranes) and ARM, so would worry about stressing an already stressed baby. I suppose, as with everything else in labour, it is all very individual and might well depend on how stretchy, etc. the cervix felt on an internal examination.

Carol J

Comment from a Dr at a meeting discussing labour ward protocols – there is no reason to keep membranes intact even in a labour that is going “normally” (don’t ask what he means by that); all membranes should be ruptured because they serve no pupose at all.’ Of course the fact that most women report more pain is neither here nor there, because there’s probably no randomised control trial that proves it!

Sooo, troops, any references etc that we can go into battle with because my initial admittedly childish reaction was to mutter along the lines of ‘ well of course mother nature has got it horribly wrong for the last 100,000 years and you’ve managed to suss it out completely in the last 100’!! .

I know the lamb can’t help the way he’s been trained but I’m beginning to think that obs are from Mars and midwives are from Venus.


Dear Cate – we all know how you feel! Rupturing the membranes speeds up delivery – that is first stage with one or two hours. Ask your obstetrician what scientific evidence there is that this is better for the mother or child (There is no such evidence!). I once read an analogy between between labour and a woman making love – warming up slowly, staying on top for a while waiting for the climax, and the orgasm a slow, pulsating experience. (Male) doctors want it to be a manly affair, energetic job for a couple of minutes,a few good pushes and out gets the result!

What is the purpose of the amniotic sac? To protect the infant from infection to cushion the baby in the womb a medium for babies to grow in and thrive. Then why are they in labour the “enemy”?


The impact of early amniotomy on mode of delivery and pregnancy outcome

Arch Gynecol Obstet 2000 Sep;264(2):63-7
Sheiner E, Segal D, Shoham-Vardi I, Ben-Tov J, Katz M, Mazor M.

OBJECTIVE: To evaluate the effect of early amniotomy in term gestation on the mode of delivery and pregnancy outcome in comparison with premature rupture of membranes (PROM) and oxytocin induction.

STUDY DESIGN: The study population consisted of 60 consecutive parturients induced by early amniotomy. The two comparison groups were 147 women admitted with term PROM and 65 patients induced by oxytocin. All study participants were evaluated prospectively and had unfavorable cervical scores.

RESULTS: The duration of the first stage of labor was significantly longer in the PROM group (987.8 +/- 572.3 min) as compared with the early amniotomy group (615.0 +/- 389.6 min) and the oxytocin induction group (650.9 +/-349.5 min, P<0.001). Higher rates of CS were found in the study group (26.7%) as compared to the controls (11.6% in the PROM and 16.9% in the oxytocin groups, p=0.012). Neonatal outcome was similar in all groups. A stratified analysis comparing the risk of CS while controlling for a previous one did not show a significant difference between the early amniotomy and the oxytocin administration groups. CONCLUSIONS: Early amniotomy is associated with a higher rate of CS. While controlling for a previous CS, both ways of induction were comparable. In order to decrease the CS rates, induction should probably start with cervical ripening techniques in order to improve the Bishop scores. PMID: 11045324 [PubMed - indexed for MEDLINE] Medline abstract: Sheiner et al (2000)

Last night I was helping a lady and her baby with breastfeeding. She had a caesarean section. She remarked that the baby had a large scratch on her neck which she assumed happened during the emergency section and also 5 deep scratches on the baby’s head. She had had an induction of labour.

On reading her notes I noted that two attempts had been made to do an ARM. The first attempt said that an ARM had been performed but no liquor seen. When her care was taken over the second midwife thought she felt membranes and attempted the second ARM. Again no liquor seen, but was documented in the notes as ARM performed.

She had asked shortly after delivery what the scratches were for and wasn’t really given an answer. I told her it was probably done when they attempted to break her waters. She wasn’t happy and I suggested she write to the head of midwifery and ask for an explanation. I know this happens from time to time, but she was worried about scarring.


When ARM seemed to help…

I ended up spending the day on labour ward with a homebirth transfer. It is almost impossible to re-create the home atmosphere. One of the midwives on duty asked me how it felt and I suddenly realised that it was probably the same as the woman – glad to be there in a funny sort of way (for support etc after 4 days at home with a long latent phase and stuck at 4cms for 9hrs despite all tricks of the trade and acupuncture), but scared of the situation spiralling out of control.

But would you believe it, I did an ARM (first one for 2years) and she went to great labour and delivered four hours later in the pool. Should I have done it at home? I still don’t think so. My concern was that post-term OP (occiput posterior presentation) and long labour, there would be meconium and what I didn’t want was her transferred in a hurry, unable to cope with contractions. We had a great birth at the end of it, but I don’t think I’ll be rushing back to labour ward!!

I think there are different practice styles around ARM. Some midwives will do it routinely with multiparas if they get hung up, and some feel that ARM belongs in hospital and will only do it there. Many felt it was of no help with primips unless they were already in transition or pushing. Was wondering if your client had a prefence beforehand about it as many home birthers are dead set against it because it falls in the list of routine interventions that are done in hospital.


Has anyone else had the experience where a mum just could not make any progress pushing and then baby almost dropped out on AROM?

I remember one mum in particular, second baby, with a bulging bag of waters. She pushed spontaneously in every position with no descent from 0 station for a couple of hours. She was absolutely determined not to have AROM.

When she seemed to be getting dispirited we had a long talk about why she felt so strongly about AROM. It turned out all her concerns could be ruled out quite easily, prolapsed cord etc. She chose to try AROM and the baby almost dropped out on the next contraction. One second I was holding a warm compress on her newly bulging perineum, the next there was baby.

I had almost identical scenario with a mum having her sixth baby, except she asked for the AROM herself after pushing longer than she could ever remember with her other babes. Her baby zoomed out without her pushing at all.

Angela C.
Student Midwife and Doula.

I have, and same for SROM (spontaneous rupture of membranes). As far as I can see, this is the main reason anyone does AROM whether in first or second stage…to speed things up.

However, I feel that rupturing intact membranes once the woman is complete (fully dilated) and pushing carried much less risk than doing it in labour. Got to be careful that it doesn’t jam a high head into acynclitism (head tilted to one side) with the next contraction.


ARM does have a place when there is delay in progress. And when there is a very large bag bulging in front of the head.


Yes, I remember this well on a couple of occasions when my labouring women (second and third babies) said they found the pressure from bulging membranes “unbearable” and requested ARM. I was very much against interfering with their labours but with no contra-indications and firm maternal requests, I went ahead. Both babies were born almost immediately after ARM.

In fact, both women said that they couldn’t & wouldn’t push as it was so painful – positive, strong women too. They said afterwards that the pressure had been far worse than crowning and that this had been the worst part of their labours.

I dare say that the births would have followed pretty quickly anyway. But, despite trying different positions, these women were closing down on themselves. I would swear to this day that these babies were beginning to retreat! On reflection, it was the right thing to do for these women. Both used the term “What a relief when my waters went!” -they then “got on” with birthing their babies.

Just to make things perfectly clear – these were ARMs performed when babies’ heads were visible (not high) and membranes ballooning. Heads were practically on the perineum. Performed because of maternal request & severe discomfort.

I do not advocate ARM for speeding up labour or enhancing contractions. I would not perform an ARM to “get the head down onto the cervix”. I feel that this is unsafe and I would most certainly query the rationale of any such practice.

Brenda, Midwife

I agree – have frequently had multiparous women request AROM for relief of pressure and I often find they tend to progress very quickly post AROM – tends to bring the head down onto the cervix and enhance uterine contractions

A fellow student midwife mentioned a similar scenario during a reflection session. I don’t recall at what point during labour or how quickly baby arrived after the ARM but the main message was the huge relief that the woman expressed once the membranes were ruptured and way she described the feeling of pressure that was so hard to cope with.


Born in a Caul – when the membranes do not break until birth

A couple of years ago I was at a birth in the caul. Third baby, 3cms on admission. Had just finished admitting her and told her I was going to collect all the paperwork together and would be back in a few minutes, but if she needed me then to use the buzzer.

I had only been out of the room about 7 minutes when she buzzed. Went back in and her husband said “She feels like she needs to push”. I walked round the bed to turn the buzzer off, she gave a push, I lifted the sheet as the baby, still in intact membranes, slid out onto the bed. I tried to break the membranes with my fingers but they wouldn’t go.

There was an amnihook on the bottom of the trolley which I used but it was a very strange sight to see this baby wriggling around inside the membranes. he even had his eyes open looking at us all. It was all over in less than a minute and he was handed to his mum.

I’ve never seen it since although there have been births with bulging membranes until the very end.


Sometimes you have to use an amnihook, but when it is a water birth the pressure of the water on the bag causes breakage.

[At a birth in a caul which Rehana attended]: The caul popped as the body delivered and we just pulled the membranes off the baby’s face and body once the mother lifted him out of the water. If the membranes don’t rupture they are easily opened with a little effort. As we have a policy of leaving the membranes intact, many babies are born this way. Being born in water aids this process as it is a much gentler birth for the baby.


Another reminiscence from my old mind. My first baby was born in her caul, 45 years ago… The ‘Old wives’ tale was that the child would never drown, so sailors were very interested in purchasing a caul for this reason. (She did not drown). My mother in law’s first baby was born in her caul also – we still have it.

Olga (retired midwife)

My grandfather was born in Eire 80+ years ago in the caul.

It was thought of as been lucky for sailors and he kept it with him through out his life, even though he never went to sea.

Many years ago he was offered £500 by a merchant seaman for the caul, but even though the money would have saved him from eviction he could not bear to part with his good luck charm.


I recently had a birth where the baby was born in the caul. Up until this birth where the caul was intact after the head had been born, there was little or no fluid around the head. This baby’s head was born and the baby was SLEEPING. We took a few photos while waiting for the shoulders to rotate. I’ve never seen anything like it. The baby had no moulding at all on her head and was very annoyed that we woke her up.


This is a lovely story. The head was probably cushioned by the fluid and pushed back around the body as it descended down the birth canal.


ARM and Amniotic Fluid Embolism

Is pushing on intact membranes associated with amniotic fluid embolism?

Amniotic fluid embolism is when fluid enters the gaping venous sinuses of the placental site and the endo-cervical vein and thus into the woman’s circulation, usually causing death by shock and DIC.

“Seen more often in rapid and tumultuous labour and disproportionatly those with pitocin induction/augumentation. Also seen with abruption. Incidence about 1: 22,000.”
Williams Obstetrics 14th edition 1971(4% pitocin rate)

I looked up 8 midwifery and obstetric books and one (Obstetrics Illustrated 4th edition) mentions AROM as causing an embolism. Three books mentioned being born in the caul but they mentioned no risk, except one which was an old obstetric nursing book from 1950. This one said that “obviously they need to be ruptured when baby born or else it will drown”!

The membranes do have to be ruptured in order to for amniotic fluid enter through the vein or placental site, so I am guessing that if they did go POP with an explosive force, then that could cause an embolism, hence controlled AROM instead of SROM would theoretically prevent this.

However, being born in the caul would prevent any fluid from forcing its way into a site as the fluid would be outside the body. I think somewhere we have all got our wires crossed about cauls and embolism. I cannot think of a single reason not to leave the caul alone.

Like water births, the infant will not try to take a first breath until air touches it, so I doubt they will try to breathe and inhale fluid, even although the inter-abdominal pressure has been relieved.

I have caught two caul babies and three more have crowned with caul and then waters have broken.with one babe we managed to get some lovely pictures but alas I do not know where they are. At any rate we were not in a panic about baby drowning, but we did remove the membranes quickly. As I have attended 300 births, all of which were non medicated, non induced/ augumented and no AROM, I could conclude that membranes remain intact in about 15% of cases until late second stage.


Having just done two home births in the last 24 hours and checked placentae, I have some simple points.

First, the membranes are on the fetal side of the placenta, so the maternal venous sinuses are not exposed to the amniotic fluid if the placenta is still attached.

Once the placenta separates from the uterus the fluid if it is still in the amniotic sack or caul the fluid is prevented from contact with the sinuses by the sack.

In case were the membranes rupture spontaneously and the labour is not tetanic nor is there any other risk for abruption eg Hypertension, then the amniotic fluid will be prevented from entering the sinuses by the placenta.


I too was brought up with this ‘theory’ about amniotic fluid embolism and pushing on intact membranes, at a time when if the midwife said it, then it was gospel and woe betide anyone who queried it.

Then someone, a very forward-thinking tutor I think, at the time said, always keep in mind – if you do any ARM and the cord comes down, or something goes wrong, then you had better have had a very GOOD reason for doing the ARM in the first place !

The moral of the story – I hardly ever do ARMs when nature is doing such a good job on her own.


Artificial Rupture of Membranes page on US Midwife Archives

AH updated 23 June 2001


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