Pregnancy and birth are marked by countless difficult and confusing decisions. If you’re expecting, asking questions, seeking input from experts, doing your own research, and paying attention to your gut instinct will all help you make informed, intuitive decisions for your family.

We’re here to help you dig into the science behind birth techniques and better understand the medical community’s current stance on them. For example, a procedure known as “vaginal seeding” — where a mother’s vaginal microbiome is wiped on an infant’s skin, nose, and mouth after being born via a C-section — is popping up on more and more websites.

Curious? Here’s everything you need to know.

What is vaginal seeding?
Before defining vaginal seeding, let’s talk about vaginal bacteria. During vaginal deliveries, babies travel through the vaginal canal and get exposed to the mother’s vaginal microbiome, also sometimes referred to as microbiota or flora. Some varieties of these bacteria, like lactobacillus, work to keep our bodies healthy and our immune systems strong by fighting off harmful bacteria that can lead to infection.

When an infant takes a gulp of this “good” vaginal bacteria and comes into contact with it as they make their way into the world, it supposedly helps the baby establish their own gut, mouth, and skin flora. Having beneficial bacteria in these places not only aids with food digestion, immune system regulation, and key mineral production, but also may prevent conditions like asthma, hay fever, eczema, certain allergies, and even obesity.

But babies born via C-section are not exposed to their mother’s vaginal bacteria, since they’re not taking a trip through the vagina. This is where vaginal seeding comes in. According to Mayo Clinic, vaginal seeding is “the practice of using cotton gauze or a cotton swab to transfer vaginal fluids to the mouth, nose, or skin of a newborn. The purpose is to transfer a mother’s vaginal bacteria to her baby.”

What does science say?
The Mayo Clinic says the benefits of vaginal seeding are unclear and further research is needed. Plus, as you might have guessed, there’s good bacteria and bad bacteria. Vaginal infections, like group B streptococcus (GBS), herpes, chlamydia, or gonorrhea could be unnecessarily passed from the mother to the baby through vaginal seeding, which is one reason many are cautious of vaginal seeding. While it’s standard to be tested and treated for STDs and GBS as a part of prenatal care to avoid passing an infection to the baby, it can be possible to pass an infection if it was contracted after testing.

This 2016 study published in Nature Medicine compared the gut flora of babies born vaginally to those born via C-section. Of the 18 babies included in the study, 7 were born vaginally and 11 via C-section. Within the C-section group, four babies underwent vaginal seeding. After 30 days, these 4 babies had microbiotas that resembled those of the babies born vaginally. However, the seven babies delivered via C-section who did not receive vaginal seeding had microbiomes that were not as bacteria-enriched.

Considering the tiny sample size and that the infants’ microbiotas were only observed after one month, the authors concluded, “… the long-term health consequences of restoring the microbiota of C-section–delivered infants remain unclear.” Because of the limited conclusive research and risk of infection, The American College of Gynecologists and Obstetricians advises against vaginal seeding unless it is performed within a research setting.

Breastfeeding for healthy ‘biomes
Though the ACOG doesn’t recommend vaginal seeding, they do suggest breastfeeding to help babies born via C-section create healthy floras. Dr. Suchitra Hourigan, a pediatric gastroenterologist, tells the New York Times, “Breastfeeding is the best and safest way to expose babies born by cesarean to their mother’s bacteria. Breast milk contains many of the same beneficial bacteria found in a woman’s vagina, and breastfeeding infants are less likely than those consuming formula to develop respiratory and gastrointestinal infections and allergies as well as chronic diseases like diabetes, obesity, and inflammatory bowel disease.”

Additionally, a 2017 study discovered that babies who received all or most of their milk from their mothers’ breasts had microbiota most similar to their mothers’.

But breastfeeding isn’t for everyone — and that’s OK. Donor breast milk banks and probiotic-rich diets can also support your child’s gut health.

If you happen to overhear someone mention vaginal seeding at work or prenatal yoga, you’ll know exactly what it is and that it’s currently not recommended by experts unless being administered in a research context. Yes — pregnancy and birth requires an exhausting amount of decision-making. But remember: thanks to doctors, organizations like ACOG, and research, you don’t have to make these decisions in the dark.

English Taylor is a San Francisco-based women’s health and wellness writer and birth doula. Her work has been featured in The Atlantic, Healthline, Refinery29, NYLON, and Modern Fertility. Follow English and her work at https://medium.com/@englishtaylor or on Instagram at @englishtaylor.