Relative Risks of Uterine Rupture

04 Jun

Again, I’m going to preface this by saying that I have never had a c-section, so I have no idea of the mental games that having one plays on you.  My main aim in posting this is to encourage and help women develop their faith in their God-given bodies.  You aren’t broken! You are an amazing woman, and I have every faith that you can have the birth you want next time.
After this fabulous article, I have included some research I have done regarding VBACs, and their risk factors compared to other birth complications.  I hope you find it useful and / or interesting.
UPDATE: I’ve updated my references to make it easier to check my facts.  I will be updating the graph soon too.  Thanks 🙂

Relative Risks of Uterine Rupture
Written by Eileen Sullivan, with assistance from her husband, Patrick.

After checking, it seems I was a bit off on the frequency of deadly lightning strikes… you are more likely to suffer a rupture than to be struck and killed by lightning, by about thirty times.  Then again, how many people do you know who HAVE been struck and killed by lightning? <s>

Ruptures are also more common than dying in a plane crash.  Henci Goer’s review of the literature on VBACs found 46 ruptures in 15,154 labors.  This equates to a 0.3% rate… or 1 in 333, if you prefer. Your annual risk of dying in a plane crash is 1 in 4000, according to one source, and 1 in 700,000 according to another.  I can’t explain the massive discrepancy between the two figures, except to quote Mark Twain about “lies, damn lies, and statistics.”

Since you asked, here are some more probability statistics for you:

Your risk of dying in a car accident, over the course of your lifetime, is between 1 in 42 and 1 in 75.  This is roughly 4 to 5 times greater than the risk of uterine rupture.

You’re about twice as likely to have your car stolen (that’s an annual risk) than to experience a uterine rupture.

Your odds of being murdered are 1 in 140 over the course of your lifetime.  That’s 2 times more likely than the risk of rupture.

The annual risk of having a heart attack is 1 in 160, 2 times more likely than rupture.  Your risk of dying from heart disease is roughly 1 in 6, or 55 times greater than your risk of rupture.

If you’re a smoker, your risk of dying from lung cancer is 1 and a half times more likely than a VBAC mom rupturing during her labor.

You’re about 17 times more likely to contract an STD this year than you are to have a uterine rupture; more likely to contract gonorrhea than to rupture, as well.

You’re 13 times more likely to get food poisoning than to rupture.

You’re more likely to have twins than a uterine rupture.  Odds of twins:  1 in 90.  That’s about 3 1/2 times the likelihood of rupture.

If you ride horseback, you’re 3 times more likely to die in a riding accident than you are to experience a uterine rupture.

If you ride a bike on the street, you are 4 times more likely to die in an accident (annual risk) than you are to suffer a rupture.

Having a serious fire in your home during the next year is twice as likely as experiencing a rupture.

You’re ten times as likely to win at roulette as you are to have a uterine rupture.

If you flip a coin, you’ll be more likely to get heads (or tails) 8 times in a row than to rupture.

The risk of cord prolapse is 1 in 37 (2.7%), or nearly ten times more likely than that of rupture.

And a final irony (heads up, those of you who want a doc to give his/her opinion on your likelihood of rupture next pregnancy!)…

You’re 6 times more likely to have a doctor who is an impostor than you are to suffer a rupture.  Two percent of docs are phonies (1 in 50), according to several sources I found.

So instead of worrying about rupture, why not take a few minutes to check up on your doctor’s credentials? 😉  It’d be a more profitable use of your time, and a substantially more likely cause for alarm.


Here are a list of facts that I have found regarding VBAC.  Please do not get scared – everything we do has risks.  This is purely to show you that the chances of something disastrous happening are rare with a VBAC, and it really is a safe way to birth your baby.

There is a:

  • 0.15% chance of VBAC uterus’ rupture in a spontaneous labour (1)
  • 99.85% of VBAC uterus’ do not rupture in spontaneous labour.
  • 1.91% chance of VBAC uterus’ rupture in a labour that is induced or augmented (1)
  • 0.88% chance of VBAC uterus’ rupture in a labour that has been induced with prostin and oxytocin (1)
  • 0.00% chance of uterine rupture causing maternal death (0.004%) (2)
  • 0.01% chance of repeat caesarean cause maternal death (0.013%) (2)
  • 0.01% chance of VBAC baby dying through a uterine rupture in a spontaneous labour (2)
  • 99.99% of VBAC babies do not die in a spontaneous labour
  • 0.05% chance of repeat caesarean babies dying (2)
  • 0.07% chance of VBAC Mum needing a hysterectomy after a uterine rupture in spontaneous labour (2)
  • 99.94% of VBAC Mums will not need a hysterectomy after a uterine rupture in spontaneous labour
  • 0.28% chance of repeat caesareans necessitating a hysterectomy (0.9% after 2 c/s, 2.41% after 3 c/s) (2)

In comparison:

  • 1.2% of women in labour have a placental abruption (3)
  • 0.17% of baby dying after a placental abruption (3)
  • 0.002% chance of a woman having a placental abruption and the baby dies
  • 1.4-6.2% of women in labour have an umbilical cord prolapse (4)
  • 9.1% of babies die after an umbilical cord prolapse (4)
  • 0.13-0.56% chance of a woman having an umbilical cord prolapse and the baby dies
  • 70% chance of  labouring mothers having a vaginal birth (5)
  • 72-90% of planned VBAC mothers have their VBAC (6)

Here’s a graph I made of these statistics:

The only statistic that I forgot to put in there was the 0.05% chance of perinatal (baby) death after a c/section, but I’m sure you can figure out where that fits.  The placental abruption and umbilical cord prolapse statistics on this graph have absolutely nothing to do with VBACs – they are a risk factor for every birth, whether VBAC or not.  I just included them for comparison purposes.

See – there is no danger reason you should sign up for a repeat c/sec – in fact, it is far safer for both you and your baby if you don’t!  You’ve just gotta work on building up your faith, and figuring out what factors may have led to your first one.  And I know – this is far easier said than done.  It would be very hard to overcome the idea that your body is broken, and that it can not birth a baby vaginally.  But you know what?  I have faith in you, & your body!  You were made for birthing!  You come from an incredibly long line of successful women who give birth vaginally!  And yes, I know, there are legitimate reasons for c-sections, but in my local area, the hospital rate is 25-30% (a common rate in westernised countries) – and the World Health Organisation states that this rate should be 15% at the absolute most!  So that’s a lot of c-sections that were performed unnecessarily.

Anyway, if you do decide to go for a vaginal birth, there are so many people out there that will support you in your journey – you just need to look!  I wish you all the best in your journey ahead.  Good luck!

My references:

(1) Dekker et al, 2010, Risk of uterine rupture in Australian women attempting vaginal birth after one prior caesarean section: a retrospective population-based cohort study.

(2) They got these statistics from: Final Statement of the National Institutes of Health (NIH) Consensus Conference on VBAC, 2010,

(3) – They got these statistics from: Ananth CV, Wilcox AJ. Placental abruption and perinatal mortality in the United States. American Journal of Epidemiology Vol. 153, No. 4 : 332-337

(4) – They got these statistics from: Murphy DJ, Mackenzie IZ. The mortality and morbidity associated with umbilical cord prolapse. British Journal of Obstetrics and Gynaecology. 1995 Oct;102(10):826-30



More VBAC Resources


Posted by on June 4, 2011 in All, c-section, trusting birth


12 responses to “Relative Risks of Uterine Rupture

  1. Anderzoid

    June 10, 2011 at 2:14 am

    I like the use of the graph & numbers. being a VBAC momma I remember weeding thru piles of data about risks in pregnancy, cesarean, & vaginal birth after cesarean. I spent every prenatal appt talking to a nurse, midwife, or OB about the numbers & risks & the success rates & safety etc etc.

    Eventually, all the info must be set aside & I had to find peace in knowing whatever happened I would deal with. It helped hving a supportive group like ICAN. I’m glad to have done the work tho. Thanx 4 taking the time to put all those numbers together.

  2. Andrea von Schoening

    July 26, 2011 at 3:22 pm

    Thank you for a great post! I have bookmarked it as a VBAC reference, and I really appreciate you including all the links.

    (One comment – on your graph, I think you have the numbers on your lower, horizontal scale out by a factor of 10 …. I think the highest number you are showing ought to be 4% and it shows as 0.4% …) Feel free to delete this comment (or the part about the graph) if you like!

    • misskalypso

      July 27, 2011 at 9:13 pm

      Thanks Andrea! All fixed now 🙂

  3. christine

    July 26, 2011 at 11:56 pm

    “A study done this year (2011) states that uterine rupture in a VBAC is comparable to women expecting their first vaginal birth “Uterine rupture rates were low in all groups, with no correlation identified… The maternal and neonatal morbidity associated with VBAC is comparable to primiparous women undergoing a vaginal birth.””

    this is from the link to Midwife Thinking’s blog that you listed, I think – she has corrected this info in her blog as of last week. The risk of uterine rupture in a VBAC mom is many times higher than a woman with no scar.

    I haven’t had a chance to check through all of your references, but the overall risk of rupture you give (.15% in spontaneous labor) is much lower than I have seen commonly referenced and even in the giving birth with confidence link that quotes the NIH stats (a very comprehensive review of all the research) lists it at 3 to 7 per 1000 – so .3% to .7%.

    You don’t say what the number for induced VBACs indicates – induction via what method? That seems overly high to me as I have seen 1.0-1.2% for pitocin induction (much higher for prostaglandins which are contraindicated for VBAC) and I have seen studies indicating that foley bulb and AROM induction do not increase the rupture rate at all.

    • misskalypso

      July 27, 2011 at 6:58 pm

      Thanks for not just being a blind reader, and actually checking my facts – I really appreciate it! It’s readers like you that make bloggers improve – well, it should do anyway!

      In response to your comment, I have gone back and re-read that research, and made it clearer where I got all my facts from.
      Thanks again 🙂

      • christine

        July 27, 2011 at 11:45 pm

        Thanks for clarifying! I don’t understand why you are putting so much weight on your first source (the australian study) which is just one published study. The 1.91% in the australian study refers to augmentation of labor with pitocin, not induction. In fact they give a lower rupture risk for *inducing* with pitocin than augmenting with it, which doesn’t make sense, as most studies have found the opposite. Your second source, the NIH consensus reviewed a much wider range of studies, and from Q3, which you have identified as your second source, gives totally different stats:

        “Considering all gestational ages, uterine rupture occurs in approximately 325 per 100,000 women undergoing trial of labor. The risk of uterine rupture for women who undergo trial of labor at term is 778 per 100,000” .3%-.8%

        “Induction of labor has been associated with uterine rupture. However, due to variation among studies with respect to indications for delivery, induction protocol, agent and dose, and subsequent use of oxytocin, it is difficult to identify an absolute risk of uterine rupture associated with induction. The risk of rupture in women at term who have their labor induced is higher (1,500 per 100,000) than the risk of rupture if labor starts spontaneously (800 per 100,000). The risk of rupture may be increased in women who are induced at more than 40 weeks (3,200 per 100,000 at more than 40 weeks versus 1,500 per 100,000 at 37 to 40 weeks). There does not appear to be an increased risk of rupture with oxytocin augmentation of spontaneous labor.”

        So, while the australian study did find a lower risk of rupture in spontaneous labor, the rest of their results make me question the validity of the study altogether.

        Also, I don’t think the risk you have of baby dying after placental abruption is correct – you cite source 3 (giving birth with confidence) which states in table 2 that “1.25 out of every 750 placental abruptions will result in a baby’s death” – .00166 – which is not 1.67% it is .167%. The risk of the baby dying from a uterine rupture is 6 out of every 100 uterine ruptures – 6%.

        If we apply each to a population of 100k you would see (using source 3 for UR risk and source 4 for placental abruption risk):

        100,000 * 0.778% UR risk = 778 uterine ruptures * 6.0% mortality = 4.68 infant deaths per 100,000 vbac attempts

        100,000 * 1.3% abruption risk = 1300 abruptions * .167% mortality = 2.17 infant deaths per 100,000 vaginal births

        Anyway – the relative risks of uterine rupture, indeed, all complications! are low, no matter which numbers you use. I am a huge VBAC supporter (I have had two already, and going for vbac #3 in january!) and it is clear that the risk of UR is comparable to other risks in any pregnancy, scarred or not.

      • misskalypso

        July 28, 2011 at 11:22 am

        Lol, my brain hurts! Currently fighting a upper respiratory infection, so not thinking totally the clearest!

        Bah! Can’t believe I made a mistake with the maths for the placental abruption! How annoying! But yay for lower risk rates! I’ve redone my maths, and yes, you are correct, the rate is 0.17%, not 1.67%. Oops! And therefore, the chance of a placental abruption occurring AND baby dies, is also lowered to 0.002%. (placental abruption chance 0.01(2) x placental abruption baby dying (0.0017)) I’m going to have to re-do my graph again! Aaaagh!

        Thankyou for your imput, regarding the Australian study verses the NIH one. I am Australian – maybe our induction and augmentation methods are slightly different? I don’t know. But the NIH statement “There does not appear to be an increased risk of rupture with oxytocin augmentation of spontaneous labor” really doesn’t seem to ‘feel’ right. I know that’s not very scientific, but how can it not be the case? And it did say “it is difficult to identify an absolute risk of uterine rupture associated with induction”. So I’ll just stick with the Aussie stats at the moment, but will acknowledge that other studies have found something different.

        Thanks again! 🙂

  4. christine

    July 28, 2011 at 11:30 am

    Yes it is all very hard to study. I ‘feel’ that augmentation has a lower risk than induction because labor did begin on its own and for whatever reason just needed a little push to keep going. Also, there is definitely a dose-dependent relationship between pitocin and uterine rupture ( and (in general) probably a lower dose of pit is needed to augment than to induce. I’m sure there’s a study on this somewhere but my pubmed search skills are failing me today (I’m sick too!)

    I do wish there were better studies on it. But overall we can take solace in the fact that ANY of these complications are very rare, and hopefully make the best decisions we can with the information available and our own intuition. Thanks for the blog! 🙂

    • misskalypso

      July 28, 2011 at 11:57 am

      Teehee, my labour with DS1 was ‘augmented’, and there was nothing ‘little’ about it. I believe it also put my son into distress. If a labour gets to a stage it needs a ‘little push’, then it obviously needs a break, and the body is not ready to birth – the same as when a labour is induced – regardless of dilation. But I understand your point.

      Why can’t they just leave well enough alone?!! If they did that in the first place, women wouldn’t need to fight to VBAC anyway! We are made to birth, and barring and pelvic abnormalities (accidents, rickets etc), birth will most likely proceed normally!

      I guess the problem with getting impartial studies is that the funding for them needs to come from somewhere, and usually that source has an agenda or influence of some kind. But yes, we’re ‘fighting’ over tiny tiny numbers, when what really needs to be done is for women to listen to their bodies, and respond to it’s promptings, rather than the promptings of fear.

      Congrats on your previous VBACs, and good luck with your next one! 🙂

  5. Kellie Clark

    July 30, 2011 at 1:18 am

    I have just literally stumbled upon your post…… is very interesting, but you say that you have never had a c-section………so I do wonder why you feel so free and able to make a comment on it? I truly believe that the majority of pregnant woman understand that birth happens though the vagina. They aren’t stupid! That is how our bodies are designed. That is classed as a “normal” birth….that is how it ‘should’ happen. And heaven forbid if you should have a C-secton ( regardless of the reason it seems)….you can repent and should aim for a VBAC. .A ” normal” birth is the ideal, but there is nothing ” normal” about an epidural, so if you have a vaginal birth with an epidural you can’t feel superior to a c-section birth. Drug free Vaginal birth……every woman in the world will hail you as an all time birth mama !!! There are a lot of us, however, who for one reason or another aren’t able to experience this. I am a woman who seems to have ” child-bearing ” hips………however, with my first child i had a loss of fluid that they let ride for a while..( public system…no Doctors to please here….who ever was on shift would have been fabulous..( and he was !!) )..then i was called in for an induction. Let me say here that at the time I was a qualified Child Care Worker with over a decade of experience and had an educative understanding of the development and birth ” process”. After being induced for 2 days with nothing happening…not a sausage!!…nothing!!!!!………..they stuck their heads in apologetically and asked how I would feel about a c-section. I just wanted my baby delivered alive and healthy. It wasn’t about me…… it was about my son. So it was. C-section………did I feel like my body was ” Broken”?? No, not at all…had I safely and carefully nurtured a baby for nine months within my body? Was he born into the world a healthy, vibrant beautiful boy……..yep!! Having been through that experince with my first baby……my next one was born via c- section too…horror! I hear you say!!! I was offered the option of a vaginal birth…said “yes please!!”…just ( sadly it would seem to many!) wasn’t to be.Same with number 3! For reasons unknown to even the doctors my body just doesn’t want to physically expel these babies from my body. So as a very healthy, normal woman with 3 incredibly beautiful boys all BORN as belly babies…I want to say, you are no less of a mother or any kind of failure if you have a c-section! I am also a qualified Doula, but found it was still so anti- c-section that I have taken a step back from that too. I bonded beautifully and successfully breastfed all of my babies into their second year and beyond so that throws a few statistics out the window!! I completely support women in birth…every woman has the right to give birth in the manner and surroundings that she chooses…I am all for home birth!!.I have supported several women during their births, all very different, all magnificent!! Not all women ” choose ” c-sections, sometimes it just happens that way…don’t make them feel like failures…they are beautiful,complete women who just birthed their babies a little different to you. Would you dare tell an adopted mother that she is not a “real mother” or that she could “do it better” next time? Sorry for the length of this post but I am just so passionate for us non-vaginal-birthers (or belly birthers)…….we are just as worthy of respect and praise as every mother is! We are all so incredibly important to each other…..don’t discriminate because of how we have our babies.

    • misskalypso

      July 31, 2011 at 10:19 am

      Thanks for your thoughts. Please, can you re-read my post? My post is written for those who are searching to figure out whether they will attempt a VBAC, or just sign up for a repeat c-section. I primarily wrote this post, after watching a few pregnant c-section mums. First off in their pregnancy, they were all gung-ho for a VBAC. But as their pregnancies progressed, and they had more and more appointments at our pretty ‘anti VBAC’ public hopspital, they started losing faith in themselves, and their bodies. I wanted to be a positive voice in their ears telling them that yes, it is totally possible. No, not certain, as no birth is, but definitely possible to have a VBAC. I didn’t think these mums would be the only ones out there that felt like this, so I decided to do a post on it.

      I don’t feel that I have anything to ‘repent’ for. Maybe for offending you? But again, I am not sure what exactly I said that offended you. Maybe it just the fact I wrote this post.

      Congratulations on your 3 babies. Of course you are no less of a mother!!! What a ridiculous idea!! I’m sorry that someone has called you that in the past!

      I think we will have to agree to disagree with the idea that anyone’s body just doesn’t want to expel babies from their bodies. Yes there are circumstances that may make it impossible, ie, malposition, pelvic injury, placental problems and obviously other reasons that I just can’t think of at the moment. I will not deny that 1 in 10 – 1 in 15 women will need c-sections. And yes, some women will need more than one. And praise God for the doctors that can do it, thereby saving so many lives. But failed induction increases the c-setion rate dramatically. And there are numerous studies showing the arbitrariness of doctors in deciding when a baby is in distress, according to fetal monitoring. But the fact that women can have babies, unknowingly by anyone else, while in comas, demonstrates that so much intervention and interference in birth is not necessary. Just wondering, and please don’t be offended at this, but had you ever wondered what might have happened if you had said ‘no’ to the induction with DS1, and then ‘no’ to the c-section, and had instead decided to go home and try again another day? Do you think the medical staff would have approved of that course of action? Of course you chose the path you felt was best at the time. As every mother does. And there is nothing to feel guilty or anything for that. But I look at my DS1’s birth, and there are so many things I would have done differently. I don’t feel guilty, even though my choices potentially put my baby at risk, I made the best decision I could with the knowledge and resources I had at the time. I am just blessed that they didn’t ask me for a c-section, because after 60 hours of contractions, I was also ready to say yes. I was just lucky 1, they didn’t ask, and 2, He was born a couple of hours later. But if I had said yes, I would like to think that I would still not feel guilty. As I said, I would have made the best decision I could with the knowledge and the resources I had available to me at the time. I say I am blessed, because I did not have major surgery, and I was able to be up and about, pretty much back to normal, within 48 hours. And yes, I know, that is not everyone’s experience of vaginal birth. Again, I was blessed.

      I can tell you are passionate for c-section mummas, and yes, you are totally worthy of respect and praise as every mother is. I am passionate for women having faith in their bodies. In them learning about the natural process of birth, and how they can best facilitate this natural process, so that they will not have to have any UNNECESSARY interventions. I am passionate about women listening to their bodies and their intuition, and to get help if they feel they need it. I am NOT passionate against c-sections, epidurals, fetal monitoring & inductions, etc – I am passionate against when these things are used when they are not medically necessary. On this point, I am sure you would agree. No mother should be subject to these things unless they are necessary (I know, epidural is a bit of a strange one to have in that list, but oh well). But if they are necessary, thank goodness we have them available! And obviously, some of those interventions will be utilised far more than others.

      Keep on supporting those Mummas! And thanks again for your thoughts.


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