“Death twice as likely by caesarean”?

I’ve said it before and I’ll say it again: No discussion of reproductive justice is complete without attention to birthing and birthing care.

A blithe, shallow, naive focus on “reproductive choice” is not enough. We don’t have free choice in birthing care right now, and there’s no point in pretending that we do.

Truly free choices are almost impossible within a societal and medical patriarchy in which birthing is considered a stupendously dangerous, messy, primitive, terrifying process which must be timed and controlled and scrutineered and interfered with in the normal course of things. Woman don’t have free choice when they’re being coerced, threatened with court orders, restrained and railroaded into “active management” of birth and surgical procedures. Women don’t have free choice when the “dead baby card” is being simplistically played, over and over, whenever they raise questions about the necessity of interventions – while risk to the woman and fetus/infant from interventions is dismissed or ignored. Women will not have free choice so long as medical unions collude with government to marginalise and suppress midwifery care. Women don’t have free choice when a standard-issue hospital birth is the only birth they can access or afford. And women don’t have free choice when they know that any mention of medical rapes[link trigger warning] will only be met with shocked silences, hasty lectures about how they should be grateful for their baby, and referrals for ‘counselling’.

Now that I’ve got that off my chest, on to the actual topic, my journalwatch post du jour: “Neonatal Mortality for Primary Cesarean and Vaginal Births to Low-Risk Women: Application of an “Intention-to-Treat” Model“. Marian F. MacDorman, Eugene Declercq, Fay Menacker, Michael H. Malloy. Birth, Volume 35 Issue 1 Page 3-8, March 2008.

You might have noticed this headline in the Sydney Morning Herald last week: “Death twice as likely by caesarean”:

BABIES born by elective caesarean are almost 2½ times more likely to die within their first month than babies born vaginally, researchers have found, adding weight to the argument that caesareans should only be carried out in emergencies.

The study, which involved more than 8 million births in the US over four years, is the first of its kind to focus on full-term babies born to women with no medical reason for choosing a caesarean over a vaginal delivery, an increasingly common phenomenon in Australia.

[…]

The study, published in the international journal Birth, only included women who had not had a previous caesarean; were giving birth to a single baby which was head down in the cervix; were between 37 and 41 weeks gestation and had none of the 16 common risk factors, such as diabetes or hypertension, associated with birth complications, in a bid to ensure that only low-risk births were evaluated.

It found the mortality rate for babies born vaginally was less than one in 1000 births while the rate for elective caesareans was 1.73 per 1000.

The obstetrician consulted for ‘balance’ by the SMH reporter pooh-poohed the increased mortality as not thaaaaat high:

A professor in obstetrics and gynaecology at the Australian National University medical school, David Ellwood, said the risk was still very small. “We have enough evidence now to know that caesareans should only be done when there is a medical indication, but when you look at the overall risk here, it is not that high.”

Is the number really “not that high”?

There are 26 000 births yearly in Western Australia alone. Taking the most charitable view, the discreprancy between the maximum C section rate recommended by the World Health Organisation (15%) and the actual C section rate (34% and rising in 2005) accounts for nearly 5 000 non-medically-necessary C sections in WA each year. Going by the numbers here, there may be an excess mortality of around 4 babies every year in WA from unnecessary C sections – and we’re one of the smaller states, accounting for around one-tenth of the country’s population. So we could be talking about around forty dead babies, every year. Not that high? Is that worth playing the “dead baby card”?

Total perinatal deaths are around 10 per 1000, most of them non-preventable, so a number approaching one-tenth of the total perinatal mortality rate is very much non-trivial. Forty percent of those 10 per 1000 perinatal deaths are low birthweight and premature babies, and one-third of the perinatal deaths are associated with lethal birth defects. There aren’t many deaths left after subtracting those two categories. Which is exactly what the authors of this study did.

[The numbers for women dying unnecessarily may be the same or higher; studies are tending to find a doubling or tripling of maternal mortality with C section, but there is a fair bit of variation in the figures, and it’s not my major focus in this post, though it is a huge issue in itself.]

The study itself

The SMH’s reporting isn’t 100% accurate, unsurprisingly. This month’s issue of “Birth” is available full-text online, and the study is here:

Birth: “Neonatal Mortality for Primary Cesarean and Vaginal Births to Low-Risk Women: Application of an “Intention-to-Treat” Model”

The study possibly addresses selection bias possibly as well as can be done without a prospective randomised controlled trial of C section vs vaginal birth for normal pregnancies. [How any such trial would pass an ethics committee, given the mounting data on the risks of C section to mother, baby, and future pregnancies, is beyond me.] The methodology was recommended by a National Institutes of Health conference.

First, a note on methodology, for those who aren’t familiar with the “intention-to-treat” concept. It is not enough to take all the C sections, and all the vaginal births, and add up the deaths for each to get the number of deaths ’caused’ by C section. That would be falling hard into the ‘correlation does not equal causation’ trap. C sections are more likely to take place after complications have occurred with a pregnancy or birth, so you would expect to see a higher perinatal mortality associated with C section than with vaginal birth. An ‘intention to treat’ analysis bases the categories on the inferred initial intention: is there evidence that the mother and carer planned for a vaginal birth, or for a C section, in the first place? This, an absolutely key feature of the study design, went completely over the head of the SMH journalist.

Methodology

The authors analysed data from over eight million births in the USA from 1999 to 2002. Only singleton, term, vertex (head-first), births with no reported medical risk factors, no placenta previa, and with no prior cesarean section were included.

The “planned vaginal delivery” category was formed by combining vaginal births and cesareans with labor complications or procedures since the original intention in both cases was presumably a vaginal delivery.

The “planned C section” category was a group who underwent C section with no labor complications or procedures.

The medical risk factors in the exclusion criteria included anemia, cardiac disease, acute or chronic lung disease, diabetes, genital herpes, hydramnios/oligohydramnios, hemoglobinopathy, chronic hypertension, pregnancy-associated hypertension, eclampsia, incompetent cervix, previous infant 4,000+ g, previous preterm or small-for-gestational-age infant, renal disease, Rh sensitization, uterine bleeding, and ‘other’. The results were controlled for sociodemographic factors (birthweight, race, parity, smoking, education) and the presence of congenital malformations.

It is particularly important to note here that the “planned vaginal birth” category did not only include babies who were ultimately born vaginally. The ‘planned vaginal birth” group included all C sections where a labour complication or procedure was recorded, indicating that vaginal birth had been planned but the plan had changed in labour for a medical reason. (This was 8% of the PVB group.) The idea is that the ‘planned C section’ group isn’t having its stats muddied with C sections after complicated labours, and the ‘planned vaginal birth’ group isn’t having its stats sanitised by only including those in which the birth happened to go swimmingly.

Results

From the abstract:

Results: The unadjusted neonatal mortality rate for cesarean deliveries with no labor complications or procedures was 2.4 times that for planned vaginal deliveries. In the most conservative model, the adjusted odds ratio for neonatal mortality was 1.69 (95% CI 1.35–2.11) for cesareans with no labor complications or procedures, compared with planned vaginal deliveries.

Conclusions: The finding that cesarean deliveries with no labor complications or procedures remained at a 69 percent higher risk of neonatal mortality than planned vaginal deliveries is important, given the rapid increase in the number of primary cesarean deliveries without a reported medical indication.

For those not familiar with 95% confidence intervals, the null hypothesis (“planned C section is associated with no change in perinatal mortality”) would only be considered unfalsified if the confidence interval included 1.0. With a leetle bit of simplification, the statisticians are 95% confident that the ‘real’ odds ratio lies within that confidence interval, 1.35-2.11.

The “most conservative model”, as well as controlling for medical and sociodemographic factors and congenital malformations, also excluded all those infants with an Apgar of less than four, including excluding states who don’t record Apgars on birth data. This was because intrapartum hypoxia might also be both a reason for performing a cesarean section and a contributor to infant death – an attempt, perhaps to detect under-reporting.

The biggest potential flaw, as I see it? Under-reporting of labour complications. Though why they would be disproportionately under-reported in the group proceeding to C section and not under-reported in the group proceeding to vaginal birth, I can’t quite figure. Anyone? The researchers didn’t just depend on the absence of data entry on complications; they also looked for ticks in the “no complications” and “no medical risk factors” checkboxes.

Now, this data isn’t perfect. It is, however, suggestive; it is based on a large and comprehensive data set, and performed in a population and an environment fairly comparable to Australia’s (in demography, health risk factors, medical technology and C section rates). It is thoroughly physiologically plausible. The OB professor quoted in the article waved it away as being a trivial number (something I debunked above), not as being seriously flawed in design.

Now what are we going to do about it?

~~~~

Background: If you haven’t been following my recent posts and comments about birthing, this will catch you up:

Western Australian birth statistics.

Skyrocketing caesarian section rate means placenta accreta is no longer just the fine print

The WHO on Birth: the “Fortaleza Declaration” and “Safe Motherhood: Care in Normal Birth”

Today’s fabricated panic: “Delayed” birth interventions causing childhood obesity?

BB Bounce (see comments)

Fetal presentations: an economist’s guide

Why are Cesarian section rates increasing so rapidly?

This subthread on ‘coached pushing‘.

Background on “Deliver big babies early!” eejitry: “macrosomia” data



Categories: gender & feminism, medicine, Science

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18 replies

  1. Is it a good sign that the study made it into the SMH? I hope so.
    I feel pretty fortunate that I a)opted for a GP not an Ob/gyn and b) gave birth both times before the GP could arrive anyway. That snippet of back and forth between OB’s you posted on your journal was enlightening in a horrifying way.

  2. Is it a good sign that the study made it into the SMH?

    I think it is a plus that in recent months the MSM in Australia has been playing more than the panicky “Baby saved by heroic doctor!” routine. I just wish they would get it right for once. Maybe employ someone with a B.Sc. or something. They don’t seem to even so much as read the abstracts.

  3. Great post. I always learn a lot from these ones.
    Cara’s last blog post..Anti-Choicers Are Furious Because Obama Cares About His Daughters

  4. Thanks Cara!
    Here’s an obstetrician opining on the value of unnecessary surgery, in the Dubbo paper:

    Dr Jackel said caesarean births could seem like a “convenient option” for some mothers, but it should not be taken lightly.
    “An elective caesarean section, if planned, is good for working ladies and it is low risk, but it’s still a major operation,” he said.

    Blame ‘working ladies’ and ‘maternal demand’! Just like the rape excuses, I can write the script for this one. And it’s all feminism’s fault.
    Lauredhel’s last blog post..Hospital predator?s appeal rejected: blames rape on victim, non-existent mental health disorder

  5. That whole “I know what women want – planned caesarians” thing really shits me. I wanted a vaginal birth, but when you have the ‘dead baby’ card thrust in your face enough times sometimes you just have to give in so that you can get by. I know my Dr was sincere, he has lost a baby with a mother in a similiar situation to mine, but I just wish he’d shut up about it and let me make my own decision in my own good time. It’s not all about maternal choice it’s about Drs and hospitals thinking they know best.

  6. It’s not hard to get really though is it?
    Stay home. Stay safe. Homebirth.
    SungaiKecil’s last blog post..Not a Happy Birthday

  7. SungaiKecil: that is hard to get, for many women. Socialisation is a very powerful force, access and affordability are major issues, as is lack of general community and family support. The limited community midwifery programmes that are available refuse to care for women based on non-women-centred criteria, as do some hospital ‘midwifery-led’ programmes.
    There is no reason why all birthing care can’t be evidence-based.

  8. I’m late, but SungaiKecil it’s incredibly hard to get. My family GP, who used to practice obstretrics in a rural area (and is hands-on, agrees with me about ‘knife-happy OBs and generally displays herself as woman-centred’ still did everything she could to dissuade me from a home birth right from the beginning. And she isn’t even able to be the ‘pregnancy’ GP for various reasons. I’m lucky enough to be using a hospital who are affiliated with an all-female GP practice who deliver so I don’t have to use a specialised OB, but none of them will attend at a home birth.
    A friend who is an independent midwife tells me that for insurance reasons, very few independents will attend at homebirths – that is, if they do they are effectively doing so at their own risk because they won’t be covered by their insurance if something goes wrong and the mother sues.
    Given all of that, the best advice my friend could give me was – try and stay at home as long as possible (which means no access to pain relief such as gas) so that by the time you get to the hospital it’s too late for them to risk an intervention but at least there’ll be someone there to catch the baby.
    And I’m a highly educated woman living in a medium sized city, so it’s not a matter of having unusually limited options in my area. This is what’s out there – or if it isn’t, none of my caregivers are telling me otherwise.
    It’s just not that simple.

  9. Ok. I am well aware of the politics surrounding birth in this country.
    Rainne, have you even tried to contact the independent midwives working in your city?
    The thing is, by settling for second best you are only supporting the status quo.
    “Socialisation is a very powerful force, access and affordability are major issues, as is lack of general community and family support. ” Well, FWIW I am one of those women who had been socialised to reject homebirth, affordability was a major constrain and I had no family support to homebirth. But for some of us, it’s about taking control of our own lives and making the best choices for our births regardless of what ‘others’ may think. They are not the ones who will have to relive birth trauma for years to come, and they aren’t the ones risking death by entering the hospital environment. I know how hard homebirth is to get, especially as a woman with a great big freakin’ “High Risk” label on your head. I am not, and never will be eligible for Community Midwifery.
    I know that all care *could* be evidence based, but if it was, less people would be making money, and as much as that serves women’s interests, it certainly does not serve care providers interests, and is therefore less likely to be presented as a viable course. They put a price on our births, and we support them in doing that by choosing them to care for us.
    Also Rainne, just because the GP practice your hospital is affiliated with is all female, please don’t be fooled into thinking they are more ‘woman centred’, females are just as capable of commitng birth rape in this community.
    I totally get what you’re saying, but it makes me angry as shit that women aren’t supported in rejecting what is offered as maternity ‘care’ in this society. If we all stopped bleating along to the slaughter house we’d all benefit from a chance to be part of a real maternity revolution.
    SungaiKecil’s last blog post..Equality Wheel

  10. Here, here SungaiKecil!
    Rebekka’s last blog post..I hate to make light of sexual harassment

  11. i would just like to comment that allthough your study seems to be well researched a c-section, to an elective c-section is the same thing with the same mortality rate.. as with those of vaginal births the main difference is that the baby doesnt have pressure on its lungs during a c-section which can cause resportory delay.. i think the way one births a child is that of their own chocie… and frankly that of their doctors… i am having an ELECTIVE C-SECTION because my child is positioned wrong.. EVEN THOUGH they could flip my child and risk getting it stuck in its cord or stress it.. i prefer to give my child the most benifical chance it can have.. and that is through a c-section… and word to the wise i know of a few babys who have died after vaginal birth because of problems overlooked… so although you may have some good research until you are faced with the chocie and its conflicts you really cant judge how unjust it is! (a c-section is actually more harmful for the mother then the child due to blood loss and infection)

  12. Your baby is the wrong way?? You mean – breech…. right?
    If my doctor was making the choice for me regarding my birth, I’d be running far, far away.
    The most beneficial birth you can give you child is one where you and the baby begin labour in your own time, and have no bullshit pressure from outsiders who see surgery as an optimal outcome (it might be for a surgeon, it’s not for you).
    There is every chance your baby could change position right up until any moment before it was born, or even *heck* be born breech…. it’s not as dangerous as you are led to believe.
    I’d suggest not believing every word of a person who gains most of out bullshitting to you, and doing some research on breech vaginal birth yourself… it’s all out there for you to access.
    Give your baby the ABSOLUTE best chance…

  13. C-section: I’m really sorry that your doctor has put you in this position. You can research for yourself at pubmed.com, where you will find that in competent hands, the risks and benefits of external cephalic version for breech presentation vs elective C section are in favour of ECV. In one recent meta-analysis, the risk of emergency C section with ECV was 0.35%. (Obstet Gynecol. 2008 Nov;112(5):1143-51) It is also worth trying to get hold of a copy of Henci Goer’s evidence-based book, “Obstetric Myths and Research Realities”. (You can read the Introduction here.)
    It is possible that your doctor has painted a distorted picture of the risks because (s)he is not skilled or confident in ECV, or prefers C section for other reasons, in which case, if you have the resources, a second opinion would be very worthwhile. Perhaps you could get in touch with a local birthing group who may be able to point you to a doctor competent in this procedure?
    It can be very confronting and upsetting when you first realise that many obstetricians, possibly including yours, are not practising evidence-based medicine. It leaves you feeling very alone. I hope you can navigate your way through this maze, and find support.
    Some questions:
    – How many weeks pregnant are you?
    – What position is the fetus in?
    – Are there any complicating factors, such as twins or major uterine anomaly?
    – What is your doctor’s C section rate? How many ECVs has (s)he performed?
    – What is the induction and episiotomy rate? (This can give you a bigger picture of how many inappropriate interventions they perform)
    – Have you been made well aware of all of the risks of C section to this baby, to you, and to you and the baby in future pregnancies? (If not, my ‘background’ and ‘similar posts’ sections above might give you a start)

  14. I just read this blog post, and it’s really informative.
    What I really hate though, is when people – mainly doctors, but often well-wishing friends too – start making the decisions about birthing.
    If someone wants a C-section.. let them without trying to talk them out of it (providing they’ve made the decision themselves).
    Same if someone wants a home birth vs a hospital one. It shouldn’t matter to other people where or how they choose to have their baby, and the mother should be fully supported in her choices.

  15. Sairah: What do you think is driving the massive increase in C sections? Do you think it’s accounted for by informed maternal choice?

  16. “If someone wants a C-section.. let them without trying to talk them out of it (providing they’ve made the decision themselves).”
    But what if their decision isn’t an *informed* decision? What if they’re basing it on their doctor having told them they’re having a “large” baby? Or on thinking it’s “easier” or “safer”?

Trackbacks

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