Vaginal seeding refers to a practice of using gauze or a swab to “transfer” vaginal fluids to an infant born via cesarean delivery. The theory behind this practice is that vaginal seeding, by exposing the infant to vaginal microbiota, would ameliorate the increased risk of autoimmune diseases, asthma, and allergic diseases seen in children not exposed to vaginal microbiota because they were delivered by cesarean in women who did not experience labor. The reduced risk of autoimmune disease, asthma, and allergic diseases observed in infants born vaginally is presumed to be associated with their intrapartum exposure to maternal vaginal microbiota (1, 2, 3, 4). It has been reported that infants born via cesarean delivery acquire different microbiota than vaginally delivered infants (5). In a study of 18 infants, of which 11 were born via cesarean delivery, swabbing the cesarean-born infant’s mouth, face, and then the rest of the body was performed with a sterile gauze pad which had been placed in the mother’s vagina for one hour prior to delivery (5). In this study, the vaginally delivered infants and those that underwent cesarean delivery with subsequent swabbing demonstrated a vaginal microbiome-like signature that was not present in the cesarean-delivered infants not exposed to the vaginal swabs (5).
While the theory of vaginal seeding may at first seem biologically plausible, it is critical to recognize that data regarding benefits and harms are lacking. It is also important to recognize that the transfer of some pathogens, which may be asymptomatic in the mother, could result in severe adverse consequences for infants, including group B streptococcus, herpes simplex virus, Chlamydia trachomatis, and Neisseria gonorrhea (6). Currently, there is only one clinical trial in the United States underway to investigate vaginal seeding (7), but the main outcome is neonatal microbiota and not clinical outcomes.
With the increasing attention given to this concept in public media, providers are being faced with incorporating vaginal seeding into clinical practices (6). At this time, based on the lack of data about the safety and harms, and the potential for harm from transfer of pathogens associated with adverse neonatal outcomes, we recommend against the practice of vaginal seeding until better data are available establishing the safety and benefits of this practice.