Image Source: Dorland’s Medical Dictionary for Health Consumers. © 2007 by Saunders, an imprint of Elsevier, Inc.
Because at least one doesn’t seem prepared to acknowledge that foetal presentation makes any difference to birthing outcomes.
Lauredhel has been astonishingly civil at Andrew’s blog in pointing out that his much-hyped position paper on the perils of increasing the Baby Bonus (the dreaded “overcooked” baby syndrome) was “purely a hypothesis-generating paper, not a paper with any data in it”, and even as such was confounded by his ignorance of obstetrics: full term births and emergency interventions are not delayed, only pre-term elective interventions can be delayed, and there is little to no evidence that delivering a baby at a lower weight at 38 weeks gestation makes any long term difference if its weight at the equivalent to 40 weeks gestation is still more than the allegedly crucial 4kg.
Andrew has ignored every single cite she has offered regarding the unnecessary rate of caesarean (and induction) intervention in Australia and elsewhere (see her previous posts, with cites), claiming that obstetricians wouldn’t possibly systematically perform unneeded procedures (no, not even though such practice is to their direct financial benefit). The kicker is that he also claimed that all her cited studies were contaminated by selection bias, and then with no sense of irony offered as his coup-de-grace a study which only looked at breech presentation births1.
Lauredhel attempted (twice) to point out that breech presentations are abnormal situations, and was ignored (quite a pattern). So let’s just make it crystal clear, shall we? The fetal malpresentation described as breech position accounts for slightly less than 3% of births. Breech births are also regarded as much more dangerous births with a higher rate of complications than cephalic/vertex births, no matter whether the birth is vaginal or c-section.
To use figures comparing outcomes for breech births for predicting outcomes for the normal range of births is flawed extrapolation in the extreme.
1. Hannah ME, Hannah WJ, Hewson SA, Hodnett ED, Saigal S, Willan AR. Term Breech Trial Collaborative Group. Planned caesarean section versus planned vaginal birth for breech presentation at term: a randomised multicentre trial. Lancet 2000;356(9239):1375-83.[link hub][Medline]
It’s also worth noting that there is some evidence that when births are viewed as dangerous by the carers, and treated as dangerous by the carers, they become more dangerous.
When I was in medical school, we were taught that “Hands off the breech!” was a Golden Rule. We were taught “Never, never, augment or induce a VBAC (vaginal birth after C section)”. Pulling on a breech-first baby deflexes the head, which then presents a larger diameter to the birth canal. Adding syntocinon and a possibly “unripe” cervix to a VBAC increases the risk of uterine rupture.
Yet, nowadays, vaginal breech births seem to involve a whole lot of tugging and fiddling, and VBACs involve a whole lot of inducing and augmenting, and those heavily interfered-with births are then used as the comparator with elective C section. No one, to the best of my knowledge (please point me to the data if I’m wrong), has compared C section in these situations with a group of truly physiological births.
The TBT was a big ol’ mess, but it’s now gospel in the obstetric community. Ask a dozen obstetricians what the methodological flaws were in the trial, and I’m guessing you’ll get a dozen blank looks. One flaw? ”Gentle traction” was applied to breech babies, accompanied by coached pushing (which decreases fetal oxygenation). *headdesk* Another one? No sensible postural management policy. In the USA, this likely means the women were put on their backs. Notably, they didn’t even bother to collect data on posture for birth in the TBT. Ignorance abounds.
And this critique doesn’t come purely from midwifery circles; it is well and truly “mainstream” (though how that word came to mean “obstetric” is beyond me). This study was published in the American Journal of Obstetrics and Gynaecology two years ago:
”Five years to the term breech trial: the rise and fall of a randomized controlled trial.”
I once heard John Quiggin say that economists should stick to economics (it was in reference to a comment about economists trying to deny the existence of global warming) and how would economists like it if scientists tried to tell us how economics works.. and well, maybe that should be include economists shouldn’t try and do obstetrics either.
Nice debating, you two.
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Have never seen husband (B.Pure Maths & Statistics, Hons) so gobsmacked by a bad stats anecdote.
I’ve never heard of a special definition for selection bias specifically for econometrics either.. and I studied econometrics.
blue milk’s last blog post..When ?mother? is just a biological social construct
Tigtog, we’re drifting a long way away from the original question. Let’s be clear: LH is arguing that c-sections and interventions are systematically performed 1-3 weeks too early, and therefore that a financial incentive to move those procedures back by 1-3 weeks will improve infant health. She cited some studies, all of which I regard as tainted by selection bias. So far as I can see, the only bit of randomised evidence on this point is the term breech study. But if you think it’s irrelevant to this discussion, then that’s fine – we can just go back to my previous point: which is that there is no medical consensus that c-sections and inducements are being done 1-3 weeks too early. All the studies that LH cites do not seem to have affected the medical consensus, at least as expressed in statements by the major professional bodies and the major textbooks.
Also, I’m afraid I cannot let your ‘astonishingly civil’ point go unremarked. Did you read LH’s first post on my blog on this topic?
You know I have been sitting here watching this debate and somehow think that it is all off point and that it is obscuring much more important points.
First, we looked at the data (including birth weight) and saw that the government incentives caused birth delay, those delayed were planned birth timing and that the babies that were delayed were on average larger. We can be forgiven (a) for thinking that poor implementation of an economic policy was impacting on a medical choice was likely to be bad and (b) that if there was evidence that it was leading to larger babies that that might be bad too.
Second, lauredhel’s point was not to dispute this but to dispute that this was ‘bad.’ Instead, the argument is that all other planned birth timings other than the 1st July 2004 and 2006 are bad in that they are occurring too early. I must say I can believe that because when the baby bonus was introduced some births appeared to be delayed by 2 weeks or more. You can’t do that I suspect unless babies were being planned 2 weeks or so earlier than they should be in general. That is what a statistical analysis does. (Also, in my own experience I saw that happen with one of our children). But excuse us for giving obstetricians the benefit of the doubt and thinking the baby bonus bump was the anomaly.
So in lauredhel is correct, our research is only lending to arguments that planned deliveries are occurring too often and too early. Why disparage it? Moreover, why not add to that the 1st April and 29th February, obstetrics conference and indeed the whole weekend effect? What is going on there? These do not indicate a medical system working purely in the interests of health outcomes.
Finally, let me ask some questions. If our research is so bad and our economic recommendation so foolish, why is the Royal College coming out and saying parents shouldn’t delay births around 1st July? So they say there is no medical problem but people shouldn’t do it? It doesn’t stack up. Why also has no maternity hospital administrator ever wanted to talk to us about this? Our concern was more about crowding in the first week of July than about slightly larger babies. Yet, no one will discuss it. That should be the concern here.
One parting note to you tigtog: the undercurrent of all this is that two male economists can’t know what they are talking about when it comes to this stuff. Complete rot. I am an economist who has happened to have delivered two babies. I have seen action and know all about birth positions, delivery options and what they might mean. I also know that someone in the last couple of weeks of pregnancy is suffering beyond what those who have not gone through it should know. The idea that they might want to use assistance, especially safe assistance, to hurry things on a little is not hard to fathom. We need to put aside the notion that it is all about the baby and consider the other patient as well.
Joshua Gans’s last blog post..Freaky predictions
Except for the consensus amongst international public health studies that the vast difference between our birth intervention rate of well over 40% compared to the Netherlands rate of less than 20% of births does not correlate with any improved maternal or infant mortality/morbidity in Australia, thus the extra procedures can logically be inferred as not medically necessary.
I read her posts to the thread to which I linked. Are you referring to a different post?
You at least seem to be more amenable to the idea that your figures actually support a pattern of overintervention. Andrew has dismissed that possibility from the start, which is part of our frustration.
It seems naive of economists not to look at financial incentives motivating the supplier of services as well as those motivating the consumer, even if you do want to give obstetricians “the benefit of the doubt” as responsible professionals – they do actually have a direct financial conflict of interest with respect to evaluating the effects of planned pre-term intervention. Parents generally just want a healthy baby and will be persuaded by medical professionals to agree to anything to further that goal – the effect of a financial incentive to wait may be merely to make them stronger in saying “well let’s see if we really need that”.
I never said anything about “can’t know”, merely that Andrew particularly has shown that he doesn’t know, and that in this particular case he kicked a spectacular own goal in dismissing other cited studies with the catch-all of “selection bias”. It certainly has nothing to do with you being male.
Lauredhel and I are both health care professionals who have studied embryology and worked with pregnant women. I’m sure that your data collection is sound, it’s part of the interpretation of the data which is at question, because from the point of view of embryological development and long-standing criticisms of obstetric over-servicing, those interpretations simply seem wrong.
tigtog: while this one paper concentrates on the motivation of the consumer all of our others are about the supplier. I urge you to have a read of them before judging what side of the debate economists are really on. And there will be more too … just wait.
Joshua Gans’s last blog post..Freaky predictions
I’m relieved to hear that you are also looking at the suppliers, Joshua. Might I suggest that in that case it’s clumsy framing of the issues to have made no mention at all of possible confounders from supplier motivations in this position paper?
You can be forgiven for thinking that but not for publishing those assumptions without checking that they were actually supported by the literature. Those assumptions have been contradicted by the literature. I can’t believe that you, a father, had never heard of the arguments about overservicing in regard to C-sections.
Suffering? That is an incredible generalisation. Are you extrapolating from personal experience to everyone now? Having carried two children to term, I don’t recall any ‘suffering’ involved in those last few weeks. Characterising this position as “all about the baby” is complete nonsense. Providing an environment which supports safe vaginal delivery, free from unnecessary medical intervention and free from fear-mongering about how ‘bad’ the last few weeks are, or how horrible the birth experience is, is ‘all about’ the wellbeing of the mother as well as the infant
Just a point too – they’re not necessarily “patients”, the mother and baby are two healthy people undergoing a process- unless and until something untoward happens.
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I dispute, as you know, that the births were “delayed”. There is no viable way to delay a birth once a woman has gone into labour. Attempts to delay preterm birth involve hospital admission, very heavy medication, and almost universal failure.
Rather, some elective inductions and C sections were pushed back from the currently routine schedule. This would have been the neutral, pre-hypothesis way to word things.
That is one possible hypothesis. Another is that it may be medically beneficial, another is that it may be medically neutral (but always organisationally inconvenient). My objection was to you leaping to the former hypothesis. Your leap seemed to be based on an assumption that obstetric practice is all appropriate and evidence-based. (The direction of the leap may have been influenced by Andrew’s anti-baby-bonus agenda).
I believe my words were along the lines of “Have you considered that this may have been a good thing?” and then getting very frustrated at the complete rejection of that even as a hypothesis.
Routine early delivery for non-medically-urgent indications are bad, yes. The tiny, tiny number that are done by maternal request and informed consent are a whatever, to me, from a medical-stats point of view; that number is far too small to make much difference to that stats. The majority of elective C sections are either medically unnecessary, or are not medically urgent but performed, for convenience, at a scheduled time before labour occurs.
Pregnancy, as you know, naturally runs for around 38-42 weeks. (Some say 37-43; some say 37-42). On the only data we have (which is sparse), normal, uninterfered with pregnancy in a primigravida runs for just over 41 weeks. Yet elective C sections were done until recently at 38 weeks, and now by many (not all) they are done at around 39 weeks. [Try finding an OB who suggest waiting until natural labour to perform a C section! Yet contraindications to this, despite it being safer for the baby, are rare – placenta previa is one, no others come to mind right now. There is absolutely no need to operate on women with twins, breech, VBAC early, even if you accept in the first place the ‘need’ for the C section, which is very much disputable.]
The very best dating methods we have can’t get any closer than a week. So I’m not sure why Andrew can’t see that these births are already taking place early in the routine scheme of things; a normal pregnancy runs from 38-42 weeks, take out babies out at 39 weeks (some of which are 38 weeks because of dating inaccuracy), and the babies are being systematically delivered 1-3 weeks early.
I asked repeatedly for evidence that medically urgent inductions and C sections were being delayed, and there is none. Strikes me that it would be reasonable to hypothesise or even assume that most or all of the ‘delayed’ interventions were not medically urgent. Did any women get eclampsia from refusing intervention for fulminating pre-eclampsia? Any mothers haemorrhaging away quietly at home for the eight hundred bucks?
You’re excused, now that you understand that the other side of the coin has merit. I personally think it was unwise to publish, then attempt to defend them, without any understanding of the field aside from having (a) child(ren) yourselves; but that’s your business. Will you be contacting the media with a modified paper that reflects your improved understanding?
I agree with you 100% on this. People who think critically about birthing have been talking about this issue for a long, long time.
Initially they seem to have pooh-poohed your point, are they now supporting it? That’s interesting. One possibility is that they realised they had shot themselves in the foot, and are now scrambling for damage control.
If you had confined your argument to overcrowding and staffing difficulties, I wouldn’t have had a problem with it, as I believe I mentioned in Andrew’s blog.
Instead, you went out on a limb, took a Apgar/birthweight correlation, assumed causation, assumed that intervention to birth earlier would obviously improve Apgars in larger babies, and constructed a medical argument around that, without a shred of evidence.
Thanks for coming in and engaging with this set of ideas in an open way. I appreciate that immensely.
We spend a fair bit of time here engaging in critical thinking, which includes questioning institutions such as obstetrics.
Since obstetrics in Australia clearly operates way, way outside of the evidence base (birthing stats here; WHO recommendations on birth care here, plus as Joshua mentioned the weekend and conference effects), questioning the profession’s received ‘wisdom’ is a very rational position.
In other words, an appeal to authority by proxy to support an assumption that current practice is evidence-based, when that ‘authority’ is an institution that clearly doesn’t practise evidence based medicine, isn’t going to fly.