One of the reasons I decided to start blogging in the first place was this post at Science and Sensibility. For those that don’t know, Science and Sensibility is the blog-face of Lamaze, and as such, they promote natural childbirth while claiming to be evidence based. Now, call me old-fashioned, but I don’t think you can be evidence-based if you have an agenda to promote anything at all. The very nature of promotion is a sell-job and that means you’ve now introduced bias into your review of evidence. Now, we all have biases, biases aren’t the problem. The problem is not declaring your biases because that misleads your readers and amplifies the degree to which they perceive you to be objective.
You can read about my biases here.
That post really got a bee in my bonnet for many reasons. The author, while reviewing the evidence, glosses over the negative prospective randomized trial in favour of focusing on small retrospective trials that support her belief that epidurals interfere with breastfeeding. She also spends quite a few words discussing basic science studies in order to “prove” that there is a biological basis for believing that epidurals interfere with breastfeeding. Well, we had a biological belief that Vioxx would be better. The medical community swallowed that horse-sh*t right up until the scandal broke and class action lawsuits ensued.
Medical research works like this:
1) you establish a biological plausibility for something…to quote Science and Sensibility,
“Epidurals can influence the fluctuation of hormone levels that play an important role in breastfeeding. A study conducted by Handlin et al (2009) found that medical interventions in connection with birth influence the activity of the hypothalamic-pituitary-adrenal axis 2 days after birth. (Adrenal gland activity, which is dependent on pituitary gland activity, which in turn is dependent on the activity of the hypothalamus is affected.) As a result of this influence, hormonal production is likely to be compromised, which will of course affect the success of breastfeeding, which depends on the release of the hormones oxytocin and prolactin.”
2) You form a hypothesis. She presents the last sentence as a factual conclusion when it is, in actuality, a hypothesis. She uses strong language, “which will of course affect,” as if anyone who thinks otherwise is an idiot. Of course it affects…how could you think otherwise. Of course the sky is blue….What she should say is, “based on this basic science study, it could be possible that medical interventions such as an epidural during labour affect the HPA axis and I wonder if those affects are great and long-lasting enough to affect breastfeeding?”
3) Next, to answer your question (prove or disprove your hypothesis), you need to design a study – either a prospective randomized study (preferred) or a restropsective study with thousands of subjects and a robust statistical model to take into account biases and confounders. Prospective randomized studies provide a higher level of evidence than any other kind because they are less subject to confounding.
4) If your study design is adequate and your enrolled numbers are large enough then the data you collect will either support or refute your hypothesis. If your study design sucks and you don’t have enough subjects, your data just confuses everyone and no conclusions can be drawn.
5) The scientific method, relies on reproducibility of results, so for your conclusions to be more robust, other independent (ie conducted by other reserach groups) studies on the same subject need to show the same result before this new information filters down and influences the decisions health care providers and patients make together. The exception would be a very large prospective randomized multi-center trial with thousands and thousands of patients that has been eagerly awaited by the medical community.
The other thing that really bothered me about this post is that so much of this post is a diatribe against the medical community and that’s a real red flag:
“…the fact that many anesthesiologists wouldn’t accept these researchers’ conclusions simply because their data is retrospective (i.e. it looks back at what happened in the past, and tries to establish causal links); anesthesiologists (like many other specialists) consider prospective randomized studies to be more reliable.”
“Clearly, too, many people involved in the debate have vested interests in continuing to promote epidurals. Caregivers who are unfamiliar (and therefore uncomfortable) supporting ‘noisy’, mobile and ‘demanding’ women (who are laboring without an epidural) are perhaps unlikely to want to change their more convenient practice; anesthetists have their livelihood to think about; drug companies which manufacture drugs such as fentanyl also have enormous profits to lose…”
Here’s the funny thing about evidence – its evidence. It should be clear and it should speak for itself. If the evidence for epidurals screwing up breastfeeding really was clear, there would be no need to insert these little snippets suggesting that the medical community is somehow out to get you…that we’re covering up the truth for our personal gain. The only purpose this paragraph serves is to create distrust and paranoia and an emotional reaction in order to bias the reader towards this woman’s point of view in the absence of the evidence that would convince a critical thinker.
There would also be no need to censor certain commentors that responded to this post and had their opinions on the subject deleted because they reached a different conclusion when they reviewed the evidence.
I can’t accept this woman’s interpetation of the evidence for any link between epidural use and breastfeeding. She clearly doesn’t “like” medical professionals and she clearly has no idea of the hierarchy of evidence or what sorts of evidence can prove causality and she weights studies that support her point of view heavily while dismissing studies that contradict her beliefs.
I have to review the evidence for myself. Do epidurals interfere with breastfeeding? At this point, I have no idea. We didn’t cover this in our residency. I am, however, really excited to find out.
I searched pubmed using various combinations of “epidural” and “breastfeeding” and “labour” and then limited things to clinical trials, meta-analysis and reviews. I included reviews because I should be able to pick up any citations I might have missed. I’m going to list the citations here. Please send me any relevant articles that you think I should also review but note that I’m only interested in clinical trials and meta-analysis. Opinion pieces and editorials need not apply and the same goes for basic science and physiology articles…lets keep the discussion focused on clinical evidence.
Here is the list:
Al-Tamimi Y, Ilett KF, Paech MJ, O’Halloran SJ, Hartmann PE. Estimation of infant dose and exposure to pethidine and norpethidine via breast milk following patient-controlled epidural pethidine for analgesia post caesarean delivery. Int J Obstet Anesth. 2011 Apr;20(2):128-34. Epub 2011 Mar 12.
Beilin Y, Bodian CA, Weiser J, Hossain S, Arnold I, Feierman DE, Martin G, Holzman I. Effect of labor epidural analgesia with and without fentanyl on infant breast-feeding: a prospective, randomized, double-blind study. Anesthesiology. 2005 Dec;103(6):1211-7.
Chen YM, Li Z, Wang AJ, Wang JM. [Effect of labor analgesia with ropivacaine on the lactation of paturients]. Zhonghua Fu Chan Ke Za Zhi. 2008 Jul;43(7):502-5. Chinese.
Devroe S, De Coster J, Van de Velde M. Breastfeeding and epidural analgesia during labour. Curr Opin Anaesthesiol. 2009 Jun;22(3):327-9. Review.
Gizzo S, Di Gangi S, Saccardi C, Patrelli TS, Paccagnella G, Sansone L, Barbara F, D’Antona D, Nardelli GB. Epidural Analgesia During Labor: Impact on Delivery Outcome, Neonatal Well-Being, and Early Breastfeeding. Breastfeed Med. 2011 Dec 13. [Epub ahead of print]
Goma HM, Said RN, El-Ela AM. Study of the newborn feeding behaviors and fentanyl concentration in colostrum after an analgesic dose of epidural and intravenous fentanyl in cesarean section. Saudi Med J. 2008 May;29(5):678-82.
Handlin L, Jonas W, Petersson M, Ejdebäck M, Ransjö-Arvidson AB, Nissen E, Uvnäs-Moberg K. Effects of sucking and skin-to-skin contact on maternal ACTH and cortisol levels during the second day postpartum-influence of epidural analgesia and oxytocin in the perinatal period. Breastfeed Med. 2009 Dec;4(4):207-20.
Henderson JJ, Dickinson JE, Evans SF, McDonald SJ, Paech MJ. Impact of intrapartum epidural analgesia on breast-feeding duration. Aust N Z J Obstet Gynaecol. 2003 Oct;43(5):372-7.
Jordan S, Emery S, Watkins A, Evans JD, Storey M, Morgan G. Associations of drugs routinely given in labour with breastfeeding at 48 hours: analysis of the Cardiff Births Survey. BJOG. 2009 Nov;116(12):1622-9; discussion 1630-2. Epub 2009 Sep 1.
Lin SY, Lee JT, Yang CC, Gau ML. Factors related to milk supply perception in women who underwent cesarean section. J Nurs Res. 2011 Jun;19(2):94-101.
Loubert C, Hinova A, Fernando R. Update on modern neuraxial analgesia in labour: a review of the literature of the last 5 years. Anaesthesia. 2011 Mar;66(3):191-212. doi: 10.1111/j.1365-2044.2010.06616.x. Review.
Reynolds F. The effects of maternal labour analgesia on the fetus. Best Pract Res Clin Obstet Gynaecol. 2010 Jun;24(3):289-302. Epub 2009 Dec 11. Review.
Uppal V, Young SJ. Smoking and ethnic group, not epidural use, determine breast feeding outcome.
Anaesthesia. 2010 Jun;65(6):652. No abstract available.
Wieczorek PM, Guest S, Balki M, Shah V, Carvalho JC. Breastfeeding success rate after vaginal delivery can be high despite the use of epidural fentanyl: an observational cohort study. Int J Obstet Anesth. 2010 Jul;19(3):273-7. Epub 2010 Jun 2.
Wilson MJ, MacArthur C, Cooper GM, Bick D, Moore PA, Shennan A; COMET Study Group UK. Epidural analgesia and breastfeeding: a randomised controlled trial of epidural techniques with and without fentanyl and a non-epidural comparison group. Anaesthesia. 2010 Feb;65(2):145-53. Epub 2009 Nov 12.
The only citations that I didn’t find that were used in the Science and Sensibility post are:
Camann W. Labor analgesia and breast feeding: avoid parenteral narcotics and provide lactation support. International Journal of Obstetric Anesthesia, 2007, Jul; 16(3):199-201
Pandya ST. Labour analgesia: Recent advances. Indian J Anaesth. 2010 Sep;54(5):400-8.
Torvaldsen S, Roberts CL, Simpson JM, et al. Intrapartum epidural analgesia and breastfeeding: a prospective cohort study. International Breastfeeding Journal, 2006,Dec11;1:24
I’m going to include the last two but the piece by Camann is an editorial so I’m skipping it.
Oh, and if anyone out there can translate the paper in Chinese by Chen et. al. I’d be really grateful. I am many things, but bilingual is not one of them!