For Newborns, 'Vaginal Seeding' Trend Could Grow into a Health Disaster

A new practice called ‘vaginal seeding’ is more likely to cause infection than promote immune health in a newborn. REUTERS/Pawan Kumar/Files

When an infant makes its journey down the birth canal, it's exposed to billions of different types of bacteria from its mother. Many are beneficial to a newborn's health. But babies delivered by cesarean section don't come in contact with vaginal microbes, and so some mothers fear their kid may be missing out on something critical to their child's development.

Scientists continue to make discoveries about how much the microbiome—the community of microbes that colonize the body—impacts human health. The microbes that live in places such as the gut, skin, mouth and genitals actually outnumber our cells from approximately 10 to 1. Recent discoveries on the microbiome have led to the development of innovations such as fecal transplantation, which has proven to be a highly effective treatment for antibiotic-resistant clostridium difficile (c.difficile ).

But the buzz about the microbiome has provided expecting mothers considering a C-section with something else to lose sleep over: Without exposure to their own microbes, could their baby's immune system be ill-equipped to take on the world? Some studies suggest the mode of infant delivery does influence whether the child will be at risk for asthma, food allergies and seasonal allergies later in life. And other studies, such as a 2010 paper published in the Proceedings of the National Academy of Sciences, show that infants born vaginally have been found to have microbiomes similar to their mother's vagina, while those delivered via C-section have a microbiome that resembles that of their mother's skin.

As a result, an increasing number of women who deliver via C-section are jumping on a new DIY trend in postnatal care, known as "vaginal seeding." It's where a mother swabs her newborn's face, mouth and eyes with her own vaginal fluid to expose the child to the bacteria.

But a paper published February 23 in BMJ recommends against this practice. The authors say vaginal seeding can introduce harmful bacteria and pathogens to a baby and might result in a serious infection. "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. We lack that certainty at present," the researchers write. "Newborns may develop severe infections from exposure to vaginal commensals and pathogens, which the mother may carry asymptomatically."

For example, as much as 30 percent of women carry group B streptococcus, the most common cause for neonatal sepsis. Through vaginal seeding a mother could also potentially pass on certain bacteria acquired from sexual intercourse, including those that cause chlamydia, gonorrhea and herpes.

This postnatal fad is in a similar vein to placentophagy, the eating of the placenta. It's well intentioned but not yet backed by science. Currently, there is just one study underway that is examining the health outcomes of C-section babies who undergo vaginal seeding. That study won't be completed until 2019. Thankfully, the authors say that this doesn't necessarily mean all hope is lost for their baby's microbiome.

"Parents and health professionals should also remember that other events in early life, such as breast feeding and antibiotic exposure, have a powerful effect on the developing microbiota," the researchers write. "Encouraging breastfeeding and avoiding unnecessary antibiotics may be much more important than worrying about transferring vaginal fluid on a swab."