What happens if you give c-section babies a vaginal microbiome?

Babies born by cesarian section have greater likelihoods of autoimmune diseases during childhood and later in life.  They also have a gut microbiome that resembles their mother’s skin right after birth. On the other hand, babies that are born vaginally have a gut microbiome that resembles their mothers’ vaginas, and are at lower risk for asthma and allergies.  Given the importance of the microbiome on immune development, many scientists believe that there may be a link between mode of delivery, the initial infant gut microbiome, and normal immune development.

One possible method to ensure a baby that is born by c-section is initially colonized by his or her mother’s vaginal microbiome is to swab the mother’s vagina and transfer her microbiome to the baby immediately after birth.  Researchers from New York University performed this exact experiment, and measured the changes that occurred in the gut after this intervention.  They published their results in the journal Nature Medicine.

In the study, 18 women were split into 3 groups: 7 women gave birth naturally, 7 women gave birth by c-section, and 4 women gave birth by c-section but had their vaginal flora transferred to the babies.  This last group of women had their vaginas screened for pathogens shortly before birth.  After the c-section, and within 2 minutes after, gauze was rubbed in the new mothers’ vaginas and then rubbed all over babies’ mouths, faces, and bodies.  The babies’ skin and gut microbiomes were measured and compared to the other two groups.  As expected, the babies born vaginally had microbiomes that resembled their mothers’ vaginas, and the babies born by c-section had microbiomes that resembled their mothers’ skin.  Interestingly, the c-section babies that were inoculated with their mothers’ vaginal microbiomes, had a microbiome that closely resembled their mothers’ vaginas, even after 1 month.  In addition, there were no adverse consequences to the microbiome transfer.

This was a small proof of concept study that successfully showed a vaginal microbiome transfer to c-section babies could properly colonize a newly born infant.  Further studies still need to confirm that the skin microbiome is unhealthy for a c-section baby, but if it is, then these vaginal flora inoculations may become a critical procedure to ensure a healthy immune system for all newborn infants.

Elective vs. acute c-section deliveries: does it make a difference?

Caesarean sections are often needed when there are complications during a pregnancy or a woman often will elect to undergo a c-section due to a variety of reasons. In some nations, c-section delivery rates are incredibly high and there are attempts to lower these numbers. In Brazil for example, 85% of births in private hospitals are c-section deliveries. Babies born via C-section have been shown to have an increased risk of disease related to immune function. Previous studies had not discriminated against elective or acute c-sections and scientists in Denmark set out to do just that.

Conducting a population based study of 750,569 children born between January 1997 and December 2012, they analyzed children born via elective c-section, acute c-section, and those born vaginally as the reference. They found that the children born by either elective or acute c-section had a higher risk of asthma, laryngitis, and gastroenteritis though electively born c-section babies had a more pronounced risk than acute c-section babies. Those born via elective c-section had an increased risk of lower respiratory tract infection and juvenile idiopathic arthritis. Babies born by acute c-section had an increased risk of ulcerative colitis and celiac disease.

There were other factors not taken into account such as if the children were breastfed or if the mothers had asthma. While not everything was able to be taken into account, with such a large sample size, it is likely that the results from this study would not have been significantly affected by other factors. Most of the effects were seen in diseases that involved the mucosal immune system. The authors believe that the reason for the differences is a result of disturbed immune function as a result of differing microbial colonization in c-section babies.