Vaginal seeding: Why we can’t recommend this C-section trend

Your baby may have your eyes and your nose, but they also share something else with you: their microbiome.

The microbiome is a complex system of bacteria that live in various parts of the body such as the skin, intestines, vagina, and mouth. These bacteria help the immune system develop, prevent and fight infection, and process food.

Babies aren’t born with a microbiome – in fact, the fetal intestinal tract is sterile at birth. Babies develop their microbiome through exposure to bacteria. Infants who are born vaginally are exposed to their mothers’ vaginal bacteria, and those bacteria colonize the babies’ intestines.

Infants born via cesarean section are not exposed to the same bacteria – although they still benefit from bacteria exposure through skin-to-skin contact and breastfeeding. Studies such as one in March 2015 have suggested that babies delivered by C-section are more susceptible to health problems such as allergies, asthma, diabetes, and autoimmune disorders, and some theorize this is because these babies were not exposed to their mothers’ vaginal flora.

In February 2016, a study was conducted to see if a process called “vaginal seeding” – exposing babies to their mothers’ vaginal bacteria – could help babies born via C-section develop a microbiome more similarly to babies born vaginally.

While the results are promising, we need a lot more research into the success and safety of such a practice before we start recommending this to pregnant women who need a C-section. Until then, there are other ways we can help promote microbiome development after a C-section.

Why is gut bacteria important?

Up to 10,000 different microbes call your body home, and in return for giving them a place to live, these bacteria help regulate your immune system, protect you from infection, and digest food.

Gut flora (bacteria in your intestines) is crucial to your health, and it’s important that your immune system recognizes these bacteria as friends, not foes. When you have an autoimmune disorder such as lupus, rheumatoid arthritis, or celiac disease, your body makes antibodies against itself, which can lead to the destruction of your tissue or organs.

The theory of oral tolerance says that the immune system is less sensitive to antigens, such as bacteria, that have previously been ingested. So, when a baby ingests a mother’s vaginal flora during delivery, it colonizes the intestines and trains the immune system not to fight it off later, which could mean a reduction in autoimmune conditions and allergies.

Vaginal seeding: Promising, but don’t try at home

In an effort to help colonize the microbiome of an infant delivered by C-section, vaginal seeding has become a trend. In this procedure, a saline-soaked gauze pad is placed in the mother’s vagina and removed shortly before the C-section. After the birth, the baby’s mouth and body is swabbed with the vaginal fluids on the gauze.

The small February 2016 study suggests it may be possible to mimic the microbiome exposure of vaginal birth in babies born via C-section. Researchers looked at 18 infants, seven born vaginally and 11 via C-section. Of the 11 delivered by C-section, vaginal seeding was used on four babies. A month after birth, the microbiomes of the four babies who received vaginal seeding more closely resembled those of the infants who were delivered vaginally than the microbiomes of those who were not exposed to their mothers’ vaginal flora.

While these results suggest that vaginal seeding may make a difference in the makeup of the microbiome, more research is needed to know whether it’s equivalent to vaginal birth. We need to look at results for more than four babies, and we need to follow these children for years to truly understand if it makes a difference in their health.

Given these unknowns, I do not recommend vaginal seeding for my patients. I especially urge mothers not to try it on their own. The mothers who participated in the study were screened for infections and given antibiotics as needed. Bacteria and viruses in the vagina such as group B Streptococcus, herpes simplex virus, and chlamydia can be dangerous to a newborn, leading to serious infections that can cause lifelong disabilities.

How we can promote microbiome development after C-section

Delivery by C-section doesn’t guarantee a child will suffer a lifetime of health problems. Most babies born via C-section live free of chronic illnesses such as allergies or asthma. However, we’re always concerned when there is an increased risk.

There are methods other than vaginal seeding we can use to help colonize a baby’s microbiome. These include:

• Delaying a baby’s first bath for 12 hours
• Skin-to-skin contact in the operating room immediately after birth
• Breastfeeding
• Using linens from home
• Avoiding unnecessary antibiotics

Of these methods, breastfeeding may be the most effective. We know that infants who are breastfed are at lower risk for developing health problems such as allergies, eczema, asthma, and diabetes – many of the same issues vaginal seeding attempts to prevent. We recommend breastfeeding for baby’s first year, but we understand this is not possible for every mom.

Talk to your physician about what you may be able to do to help in the development of your baby’s microbiome should a C-section be needed.

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