Vaginal seeding is rising in popularity, but health professionals call for caution.
Incredibly, there are trillions of microorganisms that call our bodies home. In total, each of us has an estimated 1 kg of additional living matter thriving within us.
Perhaps surprisingly, microorganisms outnumber our body's total cell count.
These startling facts have inspired an ever-growing number of scientific studies investigating the microbiota's role in sickness and health.
After all, if there are trillions of microorganisms dwelling within us, they must exert some influence over the proceedings.
Science has already uncovered evidence of the microbiota's involvement in a range of diseases, and our understanding of their importance grows daily.
As medical science plumbs the depths of our inner flora and fauna, new theories and practices are bound to emerge; one such innovative "use" of our microbiota is so-called vaginal seeding.
What is vaginal seeding?
When a baby is born via C-section, the microbiota of the infant's skin resembles that of the mother's skin. However, when a baby is born vaginally, the infant's skin microbiota resembles that of the mother's vagina.
This difference has been theorized to influence susceptibility to diseases and allergies later in life.
Vaginal seeding involves the use of a gauze swab to transfer vaginal fluid onto the newborn shortly after birth. Theoretically, this gives the baby a more "natural" biota.
The procedure garnered some interest from the popular press, generating a wider public interest. An editorial published this week in The BMJ asks the medical profession to use caution regarding this new intervention.
According to the authors - Aubrey Cunnington, senior lecturer at Imperial College London, UK, and his colleagues - "demand has increased among women attending our hospitals. Demand has outstripped both professional awareness and professional guidance on this practice."
The evidence for vaginal seeding's benefits
C-section births are certainly not uncommon. In some countries, one quarter of all births are delivered using this method. Large-scale studies have shown that C-section babies, later in life, have an increased risk of obesity, asthma and autoimmune diseases; our microbiota is known to play a role in these conditions.
Evidence also shows that early-life microbiota plays a role in the developing immune system.
Cunnington acknowledges these leaps and bounds in our understanding of the importance of infant microbiota but also calls for prudence. Perhaps the benefits of vaginal seeding will eventually be proven, but to date, it is still an unknown quantity.
To sufficiently test the efficacy of vaginal seeding, large, long-term trials will need to be conducted. To assess whether the practice does indeed generate future health benefits for the child, it will be necessary to wait until the future has arrived to observe them.
The downside of vaginal seeding
Some believe that because the practice of vaginal seeding is cheap or free, new mothers should carry it out for themselves, regardless of the lack of scientific support. Although cost-effective, vaginal seeding is not necessarily harmless.
The vagina can carry pathogens that present no symptoms in the mother. One such uninvited vaginal guest could be group B streptococcus, one of the most common causes of bacterial blood stream infections in babies, or the herpes simplex virus.
Other possible pathogens include Chlamydia trachomatis and Neisseria gonorrhoeae, both of which cause ophthalmia neonatorum - a form of neonatal conjunctivitis.
These pathogens are not routinely screened for during pregnancy; up to 30% of pregnant women are known to carry group B streptococcus. In this way, vaginal seeding has the potential to cause real damage to the child. Cunnington illustrates his point with an example:
"We have already needed to intervene to prevent vaginal seeding from a woman with genital herpes, and we expect trouble if the procedure gains wide popularity."
Cunnington has advised staff at his hospital not to perform vaginal seeding. He believes that the known risks truly do outweigh the potential positives.
The authors concede that if a woman decides to carry out the procedure of her own accord, there is nothing they can do to stop her. It is, ultimately, down to the mother. Because of the popularity of vaginal seeding, studies will no doubt follow, but it will be many years before it can be given medical backing; even then, it may not be entirely danger-free.
The author's conclusions attempt to put emphasis back on the more pressing and scientifically demonstrated concerns of newborn health:
"Encouraging breastfeeding and avoiding unnecessary antibiotics may be much more important than worrying about transferring vaginal fluid on a swab."
Medical News Today recently covered research demonstrating that vaginal seeding does indeed restore infant skin biota.