Science & Sensibility

Last week, I attended the Normal Labour & Birth International Research Conference in Vancouver, British Columbia. With over 250 attendees from 23 countries, the conference set out to disseminate research about the nature of and optimal care for physiologic labor and birth, and to garner multidisciplinary perspectives on the implications for clinical practice, perinatal outcomes, education, management, collaboration, and policy.

I went as an agent of data dissemination. My job: to use social media (blogs, Twitter) to help make sure the conference proceedings didn’t just rattle around the four walls of the conference hotel, but got out to those in the field working to improve maternity care wherever we each are.

And I have some research I want to write about – really interesting, important research from every discipline you could imagine. But I left the three-day meeting thinking more about the (broken) link between evidence and practice than about any of the new, emerging evidence. I’ll get to the new research over the coming weeks, but first, a look at two stories that dominated the conference.

#1: Home birth on the defensive?

The plenary session by Dutch physician and epidemiologist, Simone Buitendijk, might have highlighted the unique model of midwife-led primary care geared toward planned home birth for low-risk women – a model that many birth advocates and researchers look to as a beacon of hope and reason. Buitendijk herself was co-author of the definitive study of planned home birth safety, a population-based study of over half a million births that found planned midwife-attended home birth as safe as planned midwife-attended hospital birth. And a Cochrane systematic review that came out around the same time as the Dutch home birth study provided definitive evidence that midwife-led care is superior to physician-led or shared models of care. So the Dutch have gotten it right, right? Time to celebrate and emulate? No, instead of a plenary about Dutch primary maternity care as a model to emulate, Buitendijk’s talk was a sobering call to action.

According to Buitendijk, in spite of this evidence (or perhaps in direct response to this evidence?) a well-coordinated media campaign in the Netherlands over the past year has emphasized the dangers of home birth, pointing to an entirely different body of evidence: comparative data showing that Dutch perinatal mortality rates are higher than those in other European countries. Although only about 30 of the 1700 Dutch perinatal deaths occurred at home, and perinatal mortality at the population level is affected far more by incidence and management of preterm birth and congenital anomalies than by the labor and birth care of low-risk women with term pregnancies, the Dutch mass media have made this a story about midwifery care and home birth. The result: the rate of home birth has dipped below 25% for the first time in Dutch history.

#2 VBAC is Back?

Eugene Declercq, who gives – hands down – the world’s most engaging and fun lectures about perinatal statistics, had the pleasure of making an 11th hour revision to his plenary talk on vaginal birth after cesarean (VBAC) thanks to ACOG, who released their new VBAC practice guidelines at 5pm the day prior. (Hat tip to yours truly for tipping him off about the new guidelines. I even got written into his plenary remarks, as the young woman with whom he had a “stimulating conversation” that led him to “stay up all night.” Har har, Gene!)

Anyway, we see in Declercq’s talk the familiar story of how VBAC rates increased briefly then plummeted in the early 2000’s as a result of new research on uterine rupture and, more precisely, an editorial by the ob-gyn editor for the New England Journal of Medicine saying that planned repeat cesarean is “unequivocally” safer than planned VBAC.

Research driving practice! That is, if the research (or overzealous interpretations of it) supports restricting practice.

Where’s the up-tick in VBAC rates when the Cochrane systematic review was published in 2004 concluding that “Planned elective repeat caesarean section and planned vaginal birth after caesarean section for women with a prior caesarean birth are both associated with benefits and harms?” The up-tick isn’t there because by then research wasn’t driving practice – ACOG guidelines calling for “immediately available” emergency obstetric care in VBAC labors were driving practice. And it wasn’t the NIH Consensus Development Conference on VBAC or the massive AHRQ systematic review underpinning the conference (i.e., evidence) that have been heralded as the beginning of the end of hospital “VBAC bans,” it’s ACOG’s (somewhat noncommittal) move away from the “immediately available” standard.

Evidence is not driving practice. Between evidence and practice there lives some kind of cocktail of power, money, activism, media, influence and serendipity (and preservatives). The relative strength of the ingredients dictates how practices evolve. Keeping with the cocktail metaphor, the VBAC plenary ended with an invitation to consumers and our advocates to shake things up – activism being the best hope for ACOG’s new guidelines to be used to drive meaningful change for the many, many childbearing women in the United States with scarred uteruses.

This all reminds me of a third plenary talk at the Normal Birth Conference – Patti Janssen’s lecture, Transforming Research into Policy: Ingredients of Influence, in which she quotes social scientist, Martin Rein.

It also reminds me of Kay Dickerson of the Cochrane Collaboration who said, “We are only to get evidence-based healthcare in this country through consumer activism.”

More on Janssen’s plenary, and updates on the research, coming soon.

Amy Romano Uncategorized ACOG, home birth, maternity care systems, NIH Consensus Conference, Normal Labour & Birth Conference, VBAC

My intention was to have daily round-ups of the Normal Labour & Birth International Research Conference on the blog and follow it with some in-depth pieces over the next few weeks.  But between a packed agenda, phenomenal networking opportunities, a gracious hostess who dragged me (neither kicking nor screaming) to see an international fireworks competition over the harbor last night, and jet-lag, I haven’t been able to blog one bit.  The good news is that I have about 6 months worth of blog posts I could write out of this conference. So stay tuned for some quick-hit pieces and some more depth analysis, coming soon!

In the meantime, 140-character-sized updates from the conference are constantly streaming on Twitter.

"Cascade of Normal" from Vicki Van Wagner's talk on midwifery in an Inuit region of Arctic northern Canada

Amy Romano Uncategorized Normal Labour & Birth Conference

For childbirth educators and other birth professionals who want to learn more about how to read, understand, and critique research studies, I cannot recommend this book highly enough. I just discovered the other day that a new edition has been released. I also just discovered my ratty copy of my 2nd edition has gone missing (probably because it’s a favorite to lend out from my personal library). I think I’ll buy a copy of the 3rd edition and make sure to write my name in it.

It’s 40 bucks well spent. I don’t know another author who can make research methods and statistics this engaging and clear to read.

Don’t forget our Understanding Research series, too!

Amy Romano Uncategorized

A lot has been said about the new meta-analysis of home birth. (Here is an excellent summary from Jennifer Block.) Canadian physician Michael Klein has been widely quoted as saying that the meta-analysis, a potentially valuable statistical tool, was performed poorly because the researchers included studies using discredited methodology, as well as studies that are decades old. “Garbage in, garbage out.” I totally agree with this assessment. I also take issue with the fact that the researchers did not display the standard “forest plot” that customarily accompanies a meta-analysis to illustrate how the relative magnitude of observed differences in the individual studies and the pooled analysis. And I’m perplexed by the use of a fixed-effects model for the analysis of neonatal death.

But I want to take a step back and ask a larger question - is meta-analysis even appropriate for the study of home birth?

Meta-analysis is a statistical process that pools data from multiple studies. It is intended to achieve two related goals:

• have adequate statistical power to detect differences in rare but clinically important outcomes (such as perinatal mortality among babies of healthy women)
• establish a definitive answer to an important clinical question, so that policies and practices can adapt to conform to the new “truth” and other researchers don’t have to study the issue anymore.

Let’s look at these two issues separately in the context of the Wax meta-analysis.

Statistical Power

Lack of statistical power could not possibly be the rationale for conducting a meta-analysis on the safety of home birth. That’s because there already is a study large enough to detect differences in intrapartum and neonatal death. In fact, it contributed 94% of the data on planned home birth in the meta-analysis (321,307 of 342,056 planned home births). That study found virtually identical rates of neonatal death in both the planned home and planned hospital births*, with relatively narrow confidence intervals. Neonatal deaths on day 0-7 occurred in 3.4 per 10,000 of each group and when combined with intrapartum mortality and adjusted for confounding factors, the relative risk was 1.00 (95% CI 0.78 to 1.27). That means that there was a 95% likelihood that planned home birth results in somewhere between a 22% reduction and a 27% increase in intrapartum or neonatal mortality.)

By adding a bunch of smaller, older, and flawed studies, excluding the intrapartum deaths (which may be affected by intrapartum events and therefore are potentially modifiable by the birth setting) and adding deaths that occurred between 8-28 days (which are less likely to be related to intrapartum events and therefore are less modifiable by birth setting), we suddenly have nearly three times the neonatal mortality rate with planned home birth and a confidence interval you could drive a truck through?  (a 95% chance that home birth increases the risk of neonatal death by somewhere between 32% and 625%)  Hmmm…

Definitive “truth”

The other reason to undertake meta-analysis is to definitively settle a clinical question. Meta-analysis, after all, holds a privileged place atop the evidence pyramid, where it is considered the “best evidence.”  But is a deeply flawed meta-analysis really better than an adequately powered, methodologically sound study? The answer, of course, is no. All the meta-analysis does in such cases is separate the reader from the primary source of the data so that they can’t assess it for themselves, while putting the evidence-based stamp of approval on whatever statistics the meta-analysis software spits out. But people with a political motivation to authoritatively declare a certain definitive truth may realize that most people don’t bother to check to see if a meta-analysis is done appropriately or critically assess the quality of the included studies. They just go, “Oh look, there’s a meta-analysis of home birth and it said it’s 3 times riskier than hospital birth. That settles that! It’s a meta-analysis, after all!”

So if not a meta-analysis, then what?

OK, so if meta-analysis was not the right tool, what is?  And can we stop studying the safety of home birth now that we have that large study that contributed 94% of the home birth data to the meta-analysis?

The way I see it, the large study that showed equivalent perinatal outcomes between home and hospital birth tells us definitively that home birth can be safe. But it doesn’t tell us that home birth is intrinsically safe. We need to continue to study home birth using all of the tools in the research toolbox, qualitative and quantitative, to determine under what circumstances home birth is safe and how to optimize care and outcomes in all birth settings. And we need to stop pushing home birth underground in the United States where it remains a fringe alternative, poorly integrated with the maternity care system, with no standard safety net in place for women who begin labor with the intention to birth at home but turn out to need hospitalization in order to birth safely. Shame on the American Journal of Obstetrics and Gynecology for making this task even more difficult than it already was, by publishing and publicizing a junk meta-analysis.

*edited 7/12/2010 to correct a (serious) error. Sentence previously read “virtually identical rates of neonatal death in both the planned and unplanned home births.”

Amy Romano Uncategorized home birth, meta-analysis, newborns, safety, systematic review

OK, I’m not making a claim that nursing in public protects against infant mortality (but hey, it’s certainly plausible, on the public health level at least.) No, I’m writing about these two topics today because I’m hoping you’ll go read my two guest posts, hosted on two of my favorite blogs.

Over on Giving Birth With Confidence, I wrote a post called, From the Bedroom to the Board Room: How I learned to nurse in public. It’s about the fact that early in my mothering, I actually breastfed at the board room table while presenting a report to Lamaze’s Board of Directors. And it totally shaped my perception on breastfeeding, my body, and family-friendly policies:

I look back on this time now and I realize how fortunate I was. My earliest experiences of opening my baby’s and my universe to others reinforced that nursing is normal, joyful, and important. In a way, it was totally unremarkable to nurse my baby while addressing my supervisor and her Board of Directors. But at the same time, it was something to be celebrated. The people at the table weren’t weirded out that I was breastfeeding. They loved it – reveled in it. We even talked about how it is important to have babies at our conferences. Our work affects them!

That post is part of the Nursing in Public Blog Carnival. The carnival coordinators got so many great posts, they started a new (amazing!) web site, Nursing Freedom. Go spread the word!

I also have a new post up at RH Reality Check about disparities in infant mortality. I challenge birth advocates to get behind prenatal care models that are effective and proven to reduce preterm birth and close the gap between blacks and whites. I discuss my own experiences with incredible prenatal care from my home birth midwives, and come to the chilling conclusion:

THIS is how prenatal care should be. Right? Well, not necessarily. Unless and until there is a major upheaval in healthcare financing and staffing patterns, having this kind of prenatal care is a privilege. And I don’t mean privilege like “I’m so lucky.” I mean privilege in the sense that I can’t have that kind of care unless others are deprived of it.

If everyone woke up tomorrow and realized that they deserved to have every question answered, every fear and concern explored, every test/procedure/diagnosis explained, we would quickly run out of midwives to provide that care. That is, if our solution was to provide one-to-one care on the traditional prenatal schedule. In short, that kind of prenatal care, however great it is, is not scalable to levels that could benefit all women and babies.

I also discuss CenteringPregnancy, an evidence-based, relationship-centered model of group prenatal care that has shown to reduce preterm birth rates, especially among African American mothers.

I wrote that post as part of Courtroom Mama’s blog carnival at The Unnecesarean. Check out the link to read through the other important posts.

And for those of you who are interested in learning more about infant mortality and disparities in perinatal care, here are a couple of great resources.

This widget from Kids Count, a project of the Annie E. Casey Foundation, let’s you see data for any U.S. state or territory on different indicators including the infant mortality rate, child poverty rate, and teen pregnancy rate.

And here’s a fantastic recent documentary on disparities in infant mortality in Tennessee, one of the states with the highest infant mortality rates, and where funding to address the problem was recently on the chopping block. (Mercifully, the programs seem to have been spared in budget cuts.)

Amy Romano Uncategorized blog carnival, breastfeeding, infant mortality, lamaze