As a pediatric and perinatal board certified chiropractor, I help moms on a regular basis navigate the possible implications of cesarian section births on their newborns. Contrary to popular belief, c-sections have potential negative side effects for the baby. One of these potential side effects is that the baby, not having picked up the mothers birth canal bacteria, will leave the baby at a disadvantage when establishing their gut microbiome, which typically comes from the birth canal.

Passing through the birth canal has significant importance for the health of a newborn, primarily due to the exposure to maternal microbes and the physical process of vaginal delivery. This process impacts the infant’s microbiome development, immune system, and overall health in several ways:

Microbiome Seeding

Vaginal birth exposes the newborn to a diverse array of maternal microbes, which plays a crucial role in the initial colonization of the infant’s microbiome[1][5].

This “seeding” process has several benefits:

– Establishes a healthy gut microbiota, particularly rich in beneficial bacteria like Bifidobacterium and Lactobacillus species[5][7]
– Helps in the development of a stronger immune system[3]
– May reduce the risk of allergies and autoimmune disorders later in life[3][4]

 Immune System Development

The exposure to maternal microbes during vaginal birth is thought to:

– Trigger important developmental processes for normal immunological maturation[1]
– Train the body’s immune system to distinguish between potentially dangerous microbes and benign ones[6]
– Potentially lower the risk of conditions such as asthma and food allergies[6]

 Physiological Benefits

The process of passing through the birth canal also provides other physiological benefits:

– Helps clear fluid from the newborn’s lungs, potentially reducing respiratory issues[1]
– Exposes the infant to hormonal and stress responses that may be important for postnatal adaptation[1] (see below)
– May influence the development of various bodily systems, including the hypothalamic-pituitary-adrenal axis or HPA axis[1]. This neuroendocrine (nerve/hormone) system regulates the body’s stress response and adaptation.

 Long-term Health Implications

Research suggests that vaginal birth may have long-lasting health effects:

– Babies born vaginally tend to have stronger immune systems and lower rates of allergies compared to those born via cesarean section[3]
– The initial microbiome composition may influence the risk of various health conditions later in life, including metabolic and immune-related disorders[5]

It’s important to note that while these benefits are significant, modern medical interventions like vaginal seeding for C-section babies are being studied to potentially confer some of these benefits to infants who cannot be born vaginally[7]. However, the long-term effects and safety of such interventions are still under investigation. In my experience when asking moms post c-section if they were swabbed for birth canal bacteria to transfer to the baby, the majority of responses are “no”.  Attempting to perform such a swab after the labor and delivery would appear to not have the same effect, though more research must be done, since the nature of the birth canal bacteria changes during the postpartum period.

The quality of birth canal bacteria undergoes significant changes from labor and delivery to the postpartum period. These changes are characterized by a shift in microbial composition and diversity.

Microbial Composition Changes

Decrease in Lactobacillus
– During pregnancy, the vaginal microbiome is typically dominated by Lactobacillus species
– In the postpartum period, there is a significant reduction in Lactobacillus abundance[8][11][12]

Increase in Diverse Anaerobic Bacteria
– The postpartum vaginal microbiome shows an enrichment of various anaerobic bacteria, including:
– Peptoniphilus
– Prevotella
– Anaerococcus
– Streptococcus anginosus
– Bacteroides species
– Veillonella
– Porphyromonas
– Megasphaera[8][11][12]

Diversity and Community Structure

Increased Alpha-Diversity
– The postpartum period is characterized by a significant increase in microbial diversity compared to pregnancy[8][11]
– This increased diversity can persist for up to a year after delivery[8] This increased diversity may not mean that it is better than the labor and delivery bacterial diversity. More isn’t necessarily better.

Community State Types
– Postpartum vaginal communities often resemble Community State Types III and IV, which are characterized by:
– CST-III: Dominated by Lactobacillus iners
– CST-IV: Heterogeneous composition with low proportions of lactobacilli and elevated levels of various anaerobic bacteria[12] Lactobacillus is helpful in infants for digestion, and it is important to get it “in the baby” at the time of birth with the concentration being higher at birth as they pass through the birth canal.

Implications

– The postpartum changes in vaginal microbiome may have implications for maternal health, including potential increased risk of postpartum endometritis and sepsis[11].
– These alterations may also affect the initial colonization of the infant microbiome, as the birth canal microbiome plays a crucial role in seeding the newborn’s microbiota.

The quality of birth canal bacteria undergoes a significant transformation from labor and delivery to the postpartum period, characterized by decreased Lactobacillus dominance, increased microbial diversity, and alterations in the vaginal environment. These changes reflect the body’s adaptation to the postpartum state and may have important implications for both maternal and infant health.

Dr. Lou Jacobs is a Portland, Maine based pediatric and perinatal board certified chiropractor who has been working with moms and children for over 22 years. Moms and children are his top priority. He is always accepting moms and kids as new patients. His office may be reached by calling (207) 774-6251. 

Citations:
[1] https://pmc.ncbi.nlm.nih.gov/articles/PMC6265543/
[2] https://pmc.ncbi.nlm.nih.gov/articles/PMC5648605/
[3] https://raisingchildren.net.au/pregnancy/labour-birth/vaginal-caesarean-birth/vaginal-birth
[4] https://nyulangone.org/news/can-bacteria-birth-canal-boost-health-babies-born-cesarean
[5] https://karger.com/anm/article/77/Suppl.%203/11/821438/Impact-of-Delivery-Mode-on-Infant-Gut-Microbiota
[6] https://www.amnh.org/exhibitions/the-secret-world-inside-you/microbiome-at-birth
[7] https://www.science.org/content/article/swabbing-c-section-babies-mom-s-microbes-can-restore-healthy-bacteria

[8] https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01031/full
[9] https://www.science.org/content/article/swabbing-c-section-babies-mom-s-microbes-can-restore-healthy-bacteria
[10] https://www.nature.com/articles/s41522-023-00404-5
[11] https://www.nature.com/articles/srep08988
[12] https://link.springer.com/article/10.1007/s43032-020-00438-6