"Vaginal seeding" — the practice of swabbing down babies born by Caesarean with vaginal bacteria — sounds good in practice: Studies have shown that babies born by surgical methods have different microbiomes, or bacterial colonies living on and in their bodies, than those born "naturally." And because it seems increasingly clear that certain microbes have a surprising influence on infant health and development, it's no surprise that new parents want reassurance that their kids haven't gotten the short end of the microbial stick.
But according to an editorial published Tuesday in the British Medical Journal, the jury is still out on the benefits of this practice — and more importantly, the medical community has yet to show that it's safe.
In the editorial, physicians from Australia and the United Kingdom state that media reports on vaginal seeding have led to an uptick in requests for the procedure from new parents.
"It might seem reasonable to perform this simple and cheap procedure, even without clear evidence of benefit, but only if we can be sure that it is safe," the authors write. "We lack that certainty at present."
Here's what it boils down to: In theory, wiping a newborn with gauze that has been swabbed on the mother's vagina sounds pretty harmless. After all, in a traditional birth, they'd have spent some time passing through those microbial communities on their way into the world. But the problem is that we don't know what might happen if a baby is exposed to the wrong kind of bacteria during this procedure. If an infant happens to pick up a pathogen from the birth canal during labor, that's a risk that would have been difficult to avoid. But if that same baby picks up only a dangerous bug because doctors gave him a postnatal bacterial bath, we're left wondering whether the risks were worth the potential reward.
And that question becomes even more loaded when the potential rewards have yet to be proven conclusively.
"There is now quite a lot of evidence that differences in the microbiome are associated with risk of developing conditions such as allergies and obesity," lead author Aubrey Cunnington of the Department of Medicine at Imperial College London said in a statement. "However people have made a leap of logic that gut bacteria must be the link between caesarean section and risk of these diseases. But we just don't know this for sure — or whether we can even influence this by transferring bacteria on a swab from mum to baby."
So for now, these particular doctors say we should nix the procedure in hospitals — at least until there's more evidence that the swabbing is beneficial enough to warrant a small risk.
Given the ease of vaginal seeding, they realize that many parents may try to do the procedure at home. It's an issue reminiscent of problems seen with another microbial therapy: While fecal matter transplants have been proven to be incredibly helpful in curing certain gastrointestinal infections, they remain experimental for treating other conditions — and difficult to obtain for many patients. As a result, many have tried to perform the simple procedure (in which a healthy donor's fecal matter is blended with water and consumed orally or via enema) at home. Without a doctor to screen for potentially dangerous bacteria in the donor sample, the consequences can be truly dire.
A quick swab is a lot easier to do at home than blending fecal matter, so it's likely that many parents will go for it. "We should respect their autonomy but ensure that they are fully informed about the theoretical risks," the authors write. Any parents who risk at-home vaginal seeding should be honest with their doctors about it, "because this may influence a clinician's assessment of the risk of serious infection."
If you want to give your child a strong microbial start without facing the unknown risks of vaginal seeding, consider breast-feeding (which also transfers beneficial bacteria) and exposing baby to plenty of everyday germs. Recent studies have given increasing support to something called the hygiene hypothesis, which suggests that an early exposure to lots of microbes — particularly those associated with animals and farms — could help set you up for a healthier life. And most important, be smart about antibiotic use: You aren't doing your infant (or the rest of us) any favors by demanding antibiotics for a cold.