Vaginal seeding is a procedure that involves applying vaginal fluids to a newborn child delivered via cesarean section. The intention is to mimic the transfer of vaginal bacteria that would have occurred during vaginal birth. According to some researchers, this may enhance the infant’s immunity.

Doctors developed the notion of vaginal seeding following a 2016 pilot study, which found that the procedure could help to restore a healthy microbiome in infants born via cesarean section instead of vaginal delivery.

Following media reports, parents-to-be have increasingly requested the procedure. However, medical professionals remain unclear as to its potential benefits and risks.

This article describes what vaginal seeding is, why people may opt for the procedure, and its prevalence. We also outline what the research says about vaginal seeding and whether professional bodies recommend the procedure.

Finally, we discuss the potential short- and long-term benefits of vaginal seeding and how parents-to-be generally feel about the procedure.

Newborn baby holding an adult finger.Share on Pinterest
Guido Mieth/Getty Images

Vaginal seeding is a procedure that involves applying vaginal fluids to a newborn child delivered by cesarean section or “C-section.” The aim of this procedure is to recreate the natural transfer of bacteria that the newborn would have acquired from their mother during vaginal birth.

The notion of vaginal seeding followed research that suggested that babies delivered via cesarean section may lack the natural immunity of babies born vaginally. Some researchers have proposed that this may be due to the cesarean-delivery babies lacking exposure to their mother’s vaginal bacteria at birth.

A 2016 pilot study found that exposing C-section newborns to their mother’s vaginal fluids appeared to provide the infants with a microbiome similar to that of newborns delivered vaginally.

In the original 2016 vaginal seeding study, doctors placed a piece of sterile gauze inside the mother’s vagina for an hour before carrying out the C-section. The doctors then wiped the gauze over the newborn’s mouth and face and then over the rest of the skin.

Importantly, the mothers-to-be had previously received screening to ensure they were not carrying harmful pathogens that they could transfer to the infant. Each had tested negative for Group B streptococcus and bacterial vaginosis and had a normal vaginal pH of 4.5.

Cesarian sections have been rising in popularity over the past couple of decades. In the United States, approximately 1 in 3 people have their first baby by C-section. Around 80% of females who had their first baby by C-section will have their subsequent babies the same way.

However, there are no current statistics on the number of people requesting vaginal seeding as part of their birth plan.

Some researchers suggest vaginal seeding as a way of ensuring that babies born via C-section receive exposure to the microbes they would have come into contact with during vaginal delivery.

A 2019 study compared gut bacteria in both vaginal-birth and cesarian-delivery babies and found that some elements of gut flora were missing in the babies born via C-section. The researchers noted that the absence of these gut flora might be associated with the development of autoimmune diseases later in life.

Another 2019 study was one of several to suggest that babies born via C-section could have a higher risk of obesity within the first year of life.

At present, there is not enough evidence for health professionals and professional medical bodies to recommend vaginal seeding.

The American College of Obstetricians and Gynecologists (ACOG) does not recommend vaginal seeding unless people have enrolled in a research study. It believes there is insufficient data to determine whether the procedure is safe.

It is possible that parents-to-be may decide to carry out their own vaginal seeding. However, this may carry risks to the newborn.

According to the ACOG, proponents of vaginal seeding claim that the procedure helps to reduce the risk of newborns developing autoimmune disorders in later life.

Some research has identified links between the gut microbiome of babies born via C-section and excess weight or obesity in later life.

However, the ACOG highlights that there is a lack of evidence supporting the use of vaginal seeding as a way to reduce the risk of these conditions. It suggests that more robust studies are necessary to establish whether this is the case.

The ACOG also reminds healthcare professionals that both breastfeeding and early skin-to-skin contact between the mother and her newborn enables bacterial transfer between the two. The transferred bacteria can help to:

  • stimulate the newborn’s immune system
  • reduce the growth of potentially harmful bacteria
  • develop the gut microbiome
  • enable the production of certain vitamins

The main concern with vaginal seeding is the risk of transferring potentially harmful pathogens from the mother to her newborn.

It is important that people do not try vaginal seeding without assistance from a doctor, midwife, or another medical professional.

It is also important that the mother-to-be undergoes screening to ensure that she is not carrying any harmful bacteria or viruses that she may transmit to the newborn during vaginal seeding. Examples of such pathogens include:

Scientists have not sufficiently studied the effects of vaginal seeding on newborns beyond the first 30 days of life.

A 2019 study notes that medical professionals have been hesitant to promote the possibility of vaginal seeding to parents-to-be. It claims that in doing so, they have also failed to educate people about the potential risks and benefits of the procedure.

The study analyzed the quality of evidence underpinning the UK’s Royal College of Obstetricians and Gynaecologists’ guidelines on vaginal seeding. It found that only one-third of the information in the guidelines had the backing of the highest-quality scientific evidence.

As such, the researchers suggest that medical professionals should discuss the possibility of vaginal seeding with parents-to-be who enquire about the procedure.

The study also warns against medical professionals adopting a paternalistic attitude to females’ healthcare, which may not take into account the person’s wishes or concerns.

A 2021 study in New Zealand aimed to investigate pregnant females’ views on vaginal seeding. It found that 2 in 3 of the participants had never heard of the procedure. Of those who then learned about vaginal seeding through the study, most had a positive or neutral reaction to the subject.

The 2021 study also highlighted the importance of maternity healthcare professionals updating their knowledge on vaginal seeding based on the latest evidence.

Vaginal seeding is a procedure that involves applying vaginal fluids onto a newborn child delivered by cesarian section. The procedure aims to expose the newborn to the vaginal bacteria that they would have acquired during vaginal delivery.

Scientists proposed the notion of vaginal seeding after research suggested that babies born via C-section lacked the immunity of babies born vaginally. It remains unclear whether the process helps to promote immunity in later life.

Researchers also note that the procedure has the potential to transfer harmful pathogens from the mother to the child. Screening for such pathogens helps to reduce this risk.

Professional bodies do not yet advocate vaginal seeding, and research suggests there is a lack of high-quality evidence to support the current guidelines. As such, further research is necessary to help parents-to-be make informed decisions about vaginal seeding.

Parents-to-be who wish to know more about the benefits and risks of vaginal seeding should talk to their maternity healthcare professional.