Quirks & Quarks

Doctors warn mothers to not 'vaginally seed' their C-section babies

Why swabbing microbes from the birth canal could help babies born by C-section
By skipping the trip through their mother's birth canal, babies born by C-section may miss being dosed with health-stimulating good bacteria that reside there. (nata-lunata/Shutterstock)

Caesarean sections can be absolutely essential. Sometimes, for the safety of the mother and child, surgical birth rather than a vaginal delivery is the only option. But there is mounting scientific evidence that C-sections come with a hidden cost.

Many studies have found that infants born by C-section have an elevated risk of obesity, diabetes and immune systems problems like allergy and asthma. One possible explanation for this is that C-section infants are missing something. By skipping the trip through the birth canal, they miss being dosed with health-stimulating good bacteria that reside there — their mother's "vaginal microbiome." So many mothers have been taking matters into their own hands with plans to seed their babies if they're going to deliver via a C-section.

There's a reason why babies come out of the birth canal and pick up you know all that amazing bacteria to start their microbiome in their gut. It just made sense to me. So why wouldn't I help my C-section baby get that, if I could?- Katie Sorensen

Katie Sorenson from just outside of Edmonton is one such mother. She had what she called a "messy" C-section with her first son, and she vowed when she got pregnant again that things would be different her second time around. For this birth, she wanted to have as natural a birth as possible. "So I had that birth plan, but this time my husband and I decided that we also needed a birth Plan B. That's what I titled it, if things weren't going to go as planned this time."

Sorenson wanted to feel like she had some control over her C-section.

After doing some research online, Sorenson resolved to seed her baby with her bacteria from her vagina if she had to have a C-section. That literally means swabbing the mother's vaginal microbiome and smearing it over her baby.

"It just made sense to me," Sorenson said. "There's a reason why babies come out of the birth canal and pick up, you know, all that amazing bacteria to start their microbiome in their gut. It just made sense to me. So why wouldn't I help my C-section baby get that, if I could?"

This is a trend that started in England and has spread throughout the Western world. In response, the American College of Obstetricians and Gynecologists just released new guidelines saying they don't think doctors should help their patients do that. We don't have any such guidelines here in Canada.

When the big delivery day came for Sorensen, at first, she was progressing well. She thought her chances were good to have a natural delivery, but that didn't happen. Sorenson had to have another C-section. That's when she pulled out her Plan B. After talking with her doctor about vaginally seeding her baby, her doctor agreed to help her.

"They brought in some sterile gauze that had been soaked in saline, I think. And I was able to insert that."

Baby boy swabbed

Then came time for Sorenson's C-section. She had a boy.

"In the recovery room for surgery, I believe, was when they took out the gauze," Sorenson says of when it came time to vaginally seed her C-section baby. "Once I was ready to go up to my hospital room they just put the bag [with the gauze] on the bed with me [and] wheeled me to the hospital room. I just waited until he woke up and I was in the privacy of my own room. I was by myself. I unswaddled him and just proceeded to wipe. I swabbed his face around his nose and his mouth and his body as much as I could with the gauze that had been inside of me."

But why go through all this trouble? 

Increased weight gain

Dr. Maria Dominguez-Bello, a microbiologist from the New York University School of Medicine, has been researching how C-sections can alter the microbiome of the baby upon birth and what that might mean. "We decided to take mice and do a C-section to a group of mothers and compare the baby's development with those babies born vaginally. To my surprise, in the first generation the babies when the babies were separated from the mothers because they were already capable of eating solids, we found that the C-section animals had gained substantially more weight than they vaginally born — especially females that gain up to 70 per cent more weight than the vaginally delivered female babies." 

C-section animals gained substantially more weight than those that were vaginally born, Maria Dominguez-Bello found. (Adam Watt/NYU Langone Medical Center)

Does this mean that seeding your baby will reverse C-section related problems? The science isn't there yet, which is a big part of why the American College of Obstetricians and Gynecologists are warning against the practise. Dr. Kurt Wharton, an obstetrician gynecologist from Lafayette, Calif., was on the committee that came up with the recommendations. "We recommend the procedure only be performed under the process of internal review board investigation where the outcomes could be closely monitored and that people can be thoroughly counselled on the risks."

Don't know if harmful

The biggest risk is passing along an infection to the baby, which might sound counterintuitive. Why advise against a procedure that could expose a baby to an infection it could have been exposed to in the birth canal, in the first place? The reason is that doctors can't advise you to do something that hasn't been thoroughly studied.

Dr. Radha Chari, a professor of Obstetrics and Gynaecology from the University of Alberta, agrees with the U.S. recommendations. "We also don't have enough knowledge I think at this stage to apply this theory into practice. Because we don't know if it could be harmful in terms of infectious transmission. So from my perspective it's still an area for research and it's an important area for research. And until we have that strong evidence and it translates into guidelines I would say that what the American College opinion is saying is something that we would support here in Canada as well."

'It is your baby and it's your body'

But not all Canadian doctors agree. Dr. Jon Barrett, the head of the maternal-fetal medicine program at Toronto's Sunnybrook Research Institute says he wouldn't hinder nor help any patient who says they'd like to seed their baby with their vaginal microbiome. "Patients have a free choice to do what they feel is best based on their understanding of what they want to do for the baby. So I would say, 'OK I know you want to do this. It is your baby and it's your body.' It just can't be sanctioned."

Sorenson considers herself lucky that her doctor was willing to help her vaginally seed her baby. "I think at the end of the day it's up to the mom. I mean we're all just trying to do what's best for our babies. And I understand where the doctors are coming from. They need to cover their butts too."

While there isn't enough scientific evidence yet that vaginal seeding works, studies are underway. Dr. Dominguez-Bello says, "We are finishing the analysis of pilot study with 84 babies only, which is not enough to study any health outcome, but it's enough to study the microbes."

The 84 babies were either born vaginally, by C-section without any intervention, or born by C-section, but were swabbed with their mother's microbiome. "We are analyzing big one-year followup data. We published a pilot paper after one month because we observed that … for first babies that were exposed, [they] looked more like if they were born vaginally from the microbial standpoint. What we cannot tell is whether these microbial restorations lead to protection of the C-section associated disease risks."

Until the science comes in on the best way to treat the microbiome of caesarean born babies, be it vaginal seeding, pro or prebiotics, there is one thing a mother can do to help a C-section baby build up that microbiome they missed out on — and that is to breastfeed.

This is something Dr. Anita Kozyrskyj from University of Alberta's department of pediatrics studied. She discovered the group of microbes that showed a reduction after a caesarian section was replenished after one year of being breastfed. "So one could possibly recommend, and it'd be a good thing, that breastfeeding could help with some of the changes induced by caesarean section."