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Transferring Mom’s bacteria to C-section babies — but what if the bugs aren’t all friendly?


5 Star

Bacteria From Mother May Colonize Cesarean Births

Our Review Summary

Young mother giving birth to a babyThis is a well-articulated but incomplete story about a proof-of-principle study suggesting that when babies born by C-section are swabbed with their mother’s vaginal fluids, they have a microbiome more closely approximating those of their vaginally-born peers up to a month after birth. The article does a nice job of explaining the science and placing the evidence in context, but we think that it missed the mark on the potential harms of the intervention. This is a significant omission.


Why This Matters

Emerging research suggests that the types and patterns of natural bacteria growing on our bodies are important for healthy immune, digestive, and metabolic systems. Babies born by C-section do not have the benefit of being colonized by the natural bacteria in their mothers’ vaginal tracts, so an alternative method for inoculating babies with these bacteria (and an inexpensive, easy-to-implement one, at that) may even the playing field for C-section babies.


Does the story adequately discuss the costs of the intervention?

Not Applicable

The article does not discuss the costs associated with inoculation. However, it’s implied that vaginal microbial transfer is very inexpensive (it only requires a piece of gauze, saline, and a sterile bottle – all standard hospital supplies) so we won’t ding the story for this omission. With that being said, there is a tacit assumption in the article that the transfer of bacteria from the mother’s vaginal fluids to the newborn is always in the best interest of the newborn. Clearly this is not the case as we will articulate later. If there is a risk of the transfer of less than desirable bacteria, it is reasonable to assume that bacterial screening of vaginal secretions might be undertaken (which would add cost). The transfer of pathogens to the newborn inducing infection would also have a cost. While it is beyond the scope of this report, we think that thinking about the potential downsides of a new intervention is in order.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?


The article does a nice job of detailing the potential benefits of the microbial transfer and the results seen in the study, while giving the caveat that longer follow up studies are needed to understand the implications of various microbiome make-ups. But to be fair, the results are from a total of 4 newborns, hardly a number on which to base any strong conclusions.

Does the story adequately explain/quantify the harms of the intervention?

Not Satisfactory

The story says that thus far the procedure “has proved entirely safe,” but we’re talking about only four babies here! The article assumes that all the bacteria in the mother’s vaginal secretions are “friendly.”  This is clearly not the case in all patients. Significant infections can be transmitted to the newborn from bacteria resident in the mothers vaginal secretions from less than friendly bacteria including Chlamydia, Listeria and group B Strep to name a few. Suggesting that the procedure is not recommended but then pointing out that Dr. Brubaker had the procedure done for her newborn supports the notion that this is a harmless procedure — a potentially dangerous message.

Does the story seem to grasp the quality of the evidence?


The story describes the study as small and proof-of-principle, although it arguably should have made more out of the fact that only four babies underwent the swabbing procedure. That’s a very small number. Nevertheless, we think the story injects enough caution to earn a Satisfactory rating. We liked that it spelled out the next phase of study to provide readers with a realistic sense of the scientific process.

Does the story commit disease-mongering?


This article appropriately addresses the issue of increasing C-section use in U.S. and its potential repercussions.

Does the story use independent sources and identify conflicts of interest?


The article quotes several outside sources with the comments of Drs. Gilbert and Khoruts.

Does the story compare the new approach with existing alternatives?

Not Applicable

We’ll rate this as Not Applicable. There is an outstanding hypothesis that colonization of the newborn with ‘friendly” bacteria from the mother’s vaginal secretions confers some advantages. This study merely test the ability to colonize a newborn delivered by cesarean delivery artificially. There aren’t really any alternatives to discuss here.

Does the story establish the availability of the treatment/test/product/procedure?


The article mentions that this is not widely used among medical professionals but that women are sometimes doing it on their own or “arranging” to have it done. Given the potential risks of colonizing a newborn with less than friendly bacteria, we think that the story’s suggestion (and implicit encouragement) for women to do this on their own are unfortunate.  The study was intended to determine if newborns could be colonized artificially and not to study the effects in later life.

Does the story establish the true novelty of the approach?


The article places this concept in proper context.

Does the story appear to rely solely or largely on a news release?


The article clearly goes beyond the news release.


Total Score: 7 of 8 Satisfactory


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