Cesarean section, commonly referred to as a C-section, is a surgical procedure performed to deliver a baby through an incision in the mother’s abdomen and uterus. While vaginal delivery is the preferred method in most cases, C-sections may be necessary or chosen for various medical reasons. Emerging research suggests that the mode of delivery, however, can influence the development of an infant’s microbiome and have profound effect on the infant’s health.
Unlike vaginal birth, C-section delivery bypasses the birth canal, which limits exposure to the maternal vaginal and fecal microbiome. Consequently, infants born via C-section tend to have different microbial compositions in their guts, characterized by lower diversity and an overrepresentation of potentially harmful bacteria. This altered microbiome profile has been linked to an increased risk of various health conditions, including obesity, asthma, allergies, and autoimmune disorders.
“Unlike vaginal birth, C-section delivery bypasses the birth canal, which limits exposure to the maternal vaginal and fecal microbiome.”
Due to this potential impact of C-section on the infant’s microbiome, researchers have been exploring strategies to mitigate these negative effects. One promising approach is the practice of vaginal microbial seeding, where a swab from the mother’s vagina is applied to the baby’s mouth, face, and body immediately after birth. This method, called vaginal microbiota transfer (VMT) aims to transfer some of the maternal microbiota to the newborn, simulating a more natural birth process.
In a recent randomized controlled triple-blind study, published in the prestigious journal Cell, Host and Microbes by Lepeng Zhou and colleagues, 68 infants delivered by C-section were given either a vaginal microbiota transfer (VMT) or saline gauze intervention immediately after delivery. Infant neurodevelopment, as measured by the Ages and Stages Questionnaire (ASQ-3) score at 6 months, was significantly higher with VMT than saline.
Additionally, “VMT significantly accelerated gut microbiota maturation and regulated levels of certain fecal metabolites and metabolic functions, […], within 42 days after birth” suggesting potential benefits of the microbial transfer for the onset of various health conditions associated with C-sections. While this study as well as previous studies found that vaginal microbiota transfer is likely safe and effective, further research is needed.
“While this study as well as previous studies found that vaginal microbiota transfer is likely safe and effective, further research is needed.”
Future studies should explore both the long-term impacts and efficacy of vaginal microbiota transfer as well as identify additional factors that influence the microbiome composition in C-section-born infants. For example, breastfeeding has been shown to positively influence an infant’s gut microbiome and development of the immune system as breast milk contains beneficial bacteria as well as Human Milk oligosaccharides, “maternal milk factors that affect bacterial growth and metabolism”.
Consequently, it may be possible to mitigate the potential negative effects of medically indicated C-section birth on the microbiome and positively impact the long-term health of children born by C-section.