Home birth is hotly controversial, so you can bet that when any study about it is released it gets thoroughly dissected (or torn to pieces) by the side bound to clash with its conclusions. That’s exactly what’s happening to the new study being fast-tracked by the American Journal of Obstetrics and Gynecology.
The meta-analysis, led by Joseph Wax, MD, of Maine Medical Center, pools data from several studies and is making headlines that home birth triples the risk of infant death. It is also being widely criticized as “deeply flawed.” “We are puzzled by the authors’ inclusion of older studies and studies that have been discredited because they did not sufficiently distinguish between planned and unplanned home births — a critical factor in predicting outcomes,” says a press release by the American College of Nurse Midwives. “A meta-anlysis is only as good as the articles you put into it,” explains Michael Klein, MD, a professor and researcher based at the University of British Columbia. If you put “garbage in,” he says, you get “garbage out.”
But Klein is not only calling the Wax study garbage, he says the garbage stinks. Klein told CBC News that it is “a politically motivated study.” Klein’s colleague Patricia Janssen, who led a study out of British Columbia that was included in Wax’s paper, called it “sensationalist.” The grassroots Big Push for Midwives campaign charges: “Their ultimate goal is obviously to defeat legislation that would both increase access to out-of-hospital maternity care for women and their families and increase competition for obstetricians,” says Susan Jenkins, legal counsel for the campaign. (Bills are currently on the governor’s desk in New York and in the Massachusetts’ senate.)
There is of course no way to know for sure if politics is influencing science, but the Journal’s own July 1 press release announcing the article (named an “Editor’s Choice” two months before its pub date) quotes the journal’s editors stating, “This topic deserves more attention from public health officials at state and national levels.” At the very least, we can say that the editors believe the study has political implications.
Here’s what’s particularly curious: Wax and coauthors acknowledge that some of the included studies were not powered to report mortality rates, and when they analyzed the data for mortality and excluded those studies, they found “no significant differences between planned home and planned hospital births,” to quote the study verbatim. But this is not the study’s banner finding. Instead, the authors include the very studies they had excluded and report as their conclusion that “less medical intervention during planned home birth is associated with a tripling of the neonatal mortality rate.”
The ACNM calls this conjecture. “This conclusion cannot be drawn from the data presented in this meta-analysis. In fact, a number of credible studies have shown that the increased use of technology and interventions in childbirth for low risk women…do not improve birth outcomes.” The National Association of Certified Professional Midwives accuses, “the authors of this study are obscuring important information about the safety of home birth and neonatal outcomes.” The daggers are coming from all directions, including Canada and the UK, where 4 in 10 women are now offered the option of home birth.
If politics are at play here, what’s most troubling is that they are deaf to patients’ rights. The reality is that some women choose home birth, and several large, well-designed cohort studies (of actual women planning home births) have found comparable safety and significant benefits over hospital birth. Those studies (out of Canada, the Netherlands, and the U.S.) suggest that part of what makes home birth safe is the presence of an attendant trained to handle emergencies who has the ability to transfer to obstetric care if needed. Why does the (newly renamed) American Congress of OB/GYNs continue to oppose legislation that licenses and regulates home birth midwives as it prohibits its members from collaborating with them?
*UPDATE 7/10 — For a great break down of the science, look to Amy Romano’s Science & Sensibility. She asks why the authors did not graphically display their results using the customary “forest plot,” which usually accompanies meta-analyses (perhaps because it would have shown “a confidence interval you could drive a truck through”?). But she also questions whether meta-analysis is even appropriate for studying the safety of home birth. “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,” she writes. “Shame on the American Journal of Obstetrics and Gynecologists for making this task even more difficult than it already was, by publishing and publicizing a junk meta-analysis.”