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

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

This holiday weekend, which was also the sixth anniversary of my own first home birth, was busy with news of a new meta-analysis (followed by a curious revision of the meta-analysis) of the safety of home birth published in the American Journal of Obstetrics and Gynecology. The revised meta-analysis reports a 3-fold increase in neonatal mortality in planned home birth compared with planned hospital birth.

I hope to get to a more thorough deconstruction in the coming days, but in the meantime here are my preliminary notes.

1. The meta-analysis is compromised by the inclusion of a deeply flawed study that relies on birth certificates and includes preterm births, unplanned home births, and home births attended by unqualified providers. In the only analysis in which the researchers excluded this study, the significant excess of neonatal mortality disappeared.

2. The meta-analysis also includes studies that report on births that took place as early as 1976.

3. Home birth research has come a long way in the past several years. Lack of appropriate data collection and other major methodological problems have plagued this area of research. In contrast, a few new studies have really changed the game. And all of these high-quality studies, conducted in low-risk women in integrated maternity care systems, find no excess risk for babies and significant benefits for mothers. Here are some previous posts in which I reported on these studies:

• Why the largest study of planned home births won’t sway ACOG
• A new era of home birth research
• Home birth: the rest of the story

More soon!

Amy Romano Uncategorized home birth

…is up! Go check it out at Giving Birth with Confidence. What a PHENOMENAL collection of contributions about the moments, hours, and days after birth. Each of our Blog Carnivals has vastly surpassed my own expectations. I hope you’ll agree.

Amy Romano Uncategorized breastfeeding, cesarean, childbirth education, Healthy Birth Blog Carnivals, Healthy Birth Practices, home birth, interventions, maternity care systems, newborns, no separation, postpartum, safety, skin-to-skin contact

We’ve been featuring each of the Six Lamaze Healthy Birth Practices in our series of blog carnivals, and this time we’re talking about interventions. Interventions in labor and birth can be helpful – even life-saving. But there’s no denying the fact that too often they are used when a safer, more supportive approach would have worked just as well or better.

Ya Say You Want an Intervention? Well, You Know…

Women need the information about what interventions might take place in labor, when they are beneficial, what the risks are, and how to minimize those risks. Rachel Leavitt at The Beginnings of Motherhood offers a very balanced discussion of the pros and cons of two very common interventions: epidurals and pitocin. Desirre Andrews at Preparing for Birth shares a list of “hidden in plain sight” interventions that may affect a woman’s emotional state, slow her labor progress, or even cause physical harm. Lauren Wayne at HoboMama writes about her experience with an intervention that can sometimes seem invisible - vaginal exams. Well Rounded Mama discusses the disproportionate use of various interventions in women of size and argues for a supportive, proactive approach to preventing labor dystocia.

Interventions carry risks of other interventions, which introduce risks of their own. Carol van der Woude cared for a woman whose labor turned complicated and high tech when the simple act of breaking a woman’s water set into motion a cascade of intervention. It’s an all-too-common story she she tells in her post, One Thing Leads to Another. Code Name Mama also describes a typical cascade-of-interventions birth story, contrasts that story with her real birth story (made safely possible by the supportive care of a midwife and a few interventions used judiciously), and provides a treasure trove of information about all of the interventions she could have ended up with but didn’t. Kiki at The Birth Junkie describes her birth planning process as “a domino effect in reverse” – in learning how to avoid a much-unwanted episiotomy she was forced to explore alternatives to lying flat on her back and discover that many routine labor interventions restricted mobility. Learning long before labor begins about interventions and knowing which you’re okay with and under which circumstances is essential for informed decision making, she argues.

Having Interventions: An Experience in the Eye of the Beholder

When we talk about interventions that are “medically necessary” it implies that sometimes the use of interventions (and their downstream effects) are unnecessary. In reality, there are few if any interventions in labor for which you can draw a perfect line between “necessary use” and “unnecessary use”, and different women are willing to accept different risks and value different benefits, so an objective assessment of necessity may in fact be meaningless. Rixa Freeze of Stand and Deliver explores this issue in her post, Necessary/Unnecessary, a round-up of four birth stories, and suggests an alternative view:

The prominent theme in these four sets of birth stories is that the women who felt the interventions were necessary and welcome … rather than unnecessary and traumatizing…, freely chose the interventions on their own–on their own request, on their own timetable, and on their own initiative. They knew it was time for assistance. They were the primary actors in their births, rather than recipients of others’ agendas. They held the locus of control, even when that meant asking others to do things for or to them at some point (IV, epidural, Pitocin, or c-section).

One of the birth stories Rixa reflected upon was that of my sister, Katherine. Katherine, who shared her story at her midwife’s blog, Women in Charge, planned a home birth and ended up with a c-section after over three days of labor. Her birth story offers an important example of midwife-led physiologic care with timely access to needed interventions, given in a humane, and respectful manner.  Over the phone just a half a day after her cesarean, Katherine told me her birth was “fun” and audibly beamed with pride and amazement, which was about the most inspiring thing I’ve experienced in a very long time.

At the other end of the spectrum are the women whose “care” in labor is emotionally or even physically traumatic and who experience lack or loss of autonomy. Jenne Alderks at Descent Into Motherhood advocates for women who experience their births as trauma (as many as 9% of women, according to the Listening to Mothers II Survey) and coordinates a support group at Solace for Mothers. Jenne writes about these issues in the context of  her own traumatic birth story in which her efforts to exercise her right to informed refusal led her midwife to kick her out of the hospital.

Changing the Culture of Birth

Women can protect themselves from unnecessary interventions by choosing a care provider and birth setting with low intervention rates. Unfortunately, most women currently lack access to the information they need to assess intervention rates in their communities. I spoke about this issue last month with Danielle from Momotics in her radio show on the importance of Transparency in Maternity Care.

We don’t have adequate transparency now, and until we do, women will have to find out about routine practices at community hospitals by asking hospital staff or local birth advocates. Sheridan Ripley at the Enjoy Birth Blog brings us through a four part story of a woman who learned about routine hospital practices during a tour of the labor and birth unit and made a courageous choice to change hospitals and care providers just days before her estimated due date. The result was worth it!

Greater transparency is only one aspect of a larger political and cultural shift needed to reduce unnecessary interventions. Maureen Finneran Hetrick writes about some of the health care reform efforts currently underway, including payment reform and midwifery legislation, that might help rein in intervention rates in her guest post at the ICAN blog, Can healthcare reform decrease unnecessary interventions? Mom’s Tinfoil Hat gives readers an update on her fellowship research examining obstetrical culture by assessing obstetricians’ knowledge of the evidence basis for various common interventions and their attitudes toward routine use.

Amy Romano Uncategorized Healthy Birth Blog Carnivals, Healthy Birth Practices, home birth, hospitals, interventions, midwives