Wax Study Revisited

Imagine the following scenario:  a meta-analysis comparing planned homebirths to planned hospital births is published, but it has so many statistical flaws in it that the journal which originally published it goes on to print several letters to the Editor critiquing the flawed research, in order to give the authors a second chance to explain themselves.  This flawed meta-analysis is then roundly criticized by several authors of many of the individual studies used in the meta-analysis, pointing out the ways that the meta-analysis’ findings were based on a faulty a computational tool, numerical errors, mistakes in inclusion/ exclusion criteria and methodological and reporting errors.  Nevertheless, despite the widely discussed flaws in this said meta-analysis, the trade organization for all obstetricians and gynecologists in this country still goes ahead and bases their most recent opinion statement on this very same flawed study.  Sounds improbable, right?  Wrong!

This meta-analysis (Maternal and newborn outcomes in planned home birth v. planned hospital birth: a metaanalysis) by Wax et. al. (also known simply as the ‘Wax study”) is not new.  It came out last September in the American Journal of Obstetrics and Gynecology (AJOG), but the reverberations of this controversial study are still being felt in the birthing community today.  As mentioned above, the flaws in this study have been discussed on numerous blogs and in numerous articles, so there’s no need to re-hash the entire argument here. (For further reading on this, though, check out the following links: Science and Sensibility, Our Bodies Our Blog, Nature, ACNM’s response, Midwifery Today’s response).  To sum it all up, though, I quote from Michal et. al., Planned Homebirth v. Hospital Birth: A Meta-analysis Gone Wrong:

The statistical analysis upon which [the Wax meta-analysis’] conclusion was based was deeply flawed, containing many numerical errors, improper inclusion and exclusion of studies, mischaracterization of cited works, and logical impossibilities. In addition, the software tool used for nearly two thirds of the meta-analysis calculations contains serious errors that can dramatically underestimate confidence intervals (CIs), and this resulted in at least 1 spuriously statistically significant result. Despite the publication of statements and commentaries querying the reliability of the findings, this faulty study now forms the evidentiary basis for an American College of Obstetricians and Gynecologists Committee Opinion, meaning that its results are being presented to expectant parents as the state-of-the-art in home birth safety research.

And that’s really the crux of the issue right there: ACOG has based their most recent home birth committee opinion paper on the Wax findings, despite the fact that the Wax study is so controversial, and has been so loudly contested.  ACOG seems to take the Wax study as gospel truth: “Published medical evidence shows [home birth] does carry a two- to three-fold increase in the risk of newborn death compared with planned hospital births.” (i.e. the Wax findings).  But as you can see above, the Wax findings are anything but conclusive. Couple this with the fact that a recent study in the current issue of Obstetrics & Gynecology (ACOG’s very own publication, aka the Green Journal) found that two-thirds of all of ACOG’s practice guidelines have no basis in science, and we have a very serious cause for alarm.  As one of the letters to the Editor at AJOG pointed out in regards to the Wax Study,  this is the dangerous practice of communicating bad science to the public.  To quote liberally from this letter to the Editor:

These practices are unethical, causing harm through unfounded confusion and fear, and misleading policymakers and the public. The Singapore statement on research integrity represents the first international effort to unify policies, guidelines, and codes of conduct for researchers worldwide.4   Accordingly, the AJOG publication would fail on 2 counts: (1) poor quality of the study; and (2) author recommendations made beyond what the data support and outside of their professional expertise. Obstetricians are not the leading professional group in home birth and midwifery-led care, and should not reach policy conclusions in isolation. It is essential to use appropriate subject peer reviewers: in this case midwife and epidemiology experts in studies examining midwifery care and birth setting.

Obstetricians have never been the experts on home birth.  In my own personal experience, I cannot think of a single obstetrician who has even seen a home birth.  Nevertheless, as Melissa Cheyney writes in the  Huffington Post (Why Home Births Are Worth Considering), the Wax study is only serving to fan the flames between the obstetrical/ medical community and the home birth community (I purposely refrain from saying the homebirth/ midwifery community, because I feel like midwives can and do and SHOULD straddle the gap between the home birth community and medicine, offering high-touch, low-tech intervention as we do, and advocating for all women, everywhere, regardless of their birth choices or location of birth).  When home birth is seen as more dangerous than hospital birth by obstetrical “experts”, what then happens to the women and families who still choose to have a home birth?  Are they considered crackpots and lunatics endangering the lives of their babies?  What happens if they need to transfer to a hospital?  What happens if they need to transfer to a hospital but the midwife is reluctant to make the transfer based on the stigma and ostracizing treatment she and the family will receive in the hospital setting?  Will the barriers to midwives choosing to attend home births continue to rise so high that ultimately they can no longer provide this service? And if that happens, where does that leave the women who will still choose to have a home birth anyway, without any medical provider available to attend them?

So long as ACOG’s opinion on home birth continues to be based on poor science, we’ll continue to move further and further away from what this country truly needs: an integrated model of care, where women who choose home births and the midwives who serve those women are backed up by obstetricians and the medical model of care, allowing for safe transfers when needed without stigma, judgement or blame.

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