Experts warn of risks of vaginal 'seeding' after C-section births

Feb 25, 2016 at 8:13 a.m. ET
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Have you heard of vaginal "seeding?" Also known as "micro birthing," it's the latest C-section delivery trend and it's becoming increasingly popular on U.K. maternity wards.

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The practice involves using a swab to cover a newborn baby's mouth, face and body in vaginal fluid immediately after a caesarean birth.

Babies born vaginally are exposed to a range of beneficial bacteria known as microbiota when they travel down the birth canal but babies born by C-section don’t have the same exposure.

The idea behind vaginal seeding is that the immune system of C-section babies is boosted through exposure to this bacteria reducing the risk of infection, disease and allergies later in life.

However experts have said there are no proven benefits of the practice and, worryingly, have warned that "seeded" babies could be at risk of serious infection.

In an article for the British Medical Journal, Dr. Aubrey Cunnington, a clinical senior lecturer from Imperial College London; Aniko Deierl, a consultant neonatologist at St Mary's hospital, London; and Eimear Brannigan, a consultant in infectious diseases and infection prevention and control at Charing Cross hospital, London, said demand for vaginal seeding in the U.K. "has outstripped both professional awareness and professional guidance on this practice."

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The experts warned that new mums could be putting their babies' health at risk, for example from group B strep (GBS), a serious infection that can be fatal. Around a quarter of pregnant women carry GBS at any one time, with a small number of babies becoming infected during birth.

"There is now quite a lot of evidence that differences in the microbiome [the collection of bacteria living in the gut] are associated with risk of developing conditions such as allergies and obesity," said Dr. Cunnington. "However people have made a leap of logic that gut bacteria must be the link between caesarean section and risk of these diseases. But we just don't know this for sure — or whether we can even influence this by transferring bacteria on a swab from mum to baby."

Because pregnant women are not tested for GBS in the U.K. a caesarean birth would actually protect a baby from the infection.

"There are also other conditions that cause no symptoms in the mother, such as chlamydia, gonorrhoea and herpes simplex virus, that could be transferred on the swab," said Dr. Cunnington. "One colleague had to intervene when a mother with genital herpes, who had undergone a caesarean section, was about to undertake this process. Swabbing would have potentially transferred the herpes virus to the baby."

Dr. Patrick O'Brien, spokesman for the Royal College of Obstetricians and Gynaecologists, told The Guardian: "There is increasing evidence to suggest that there are differences in the gut bacteria found in babies born naturally or via caesarean section before labour. Those born through caesarean section appear to be at increased risk of asthma, allergies and food intolerances in later life due to a lack of 'protective' bacteria.

"[However] we would […] not recommend [vaginal seeding] until there is evidence that it is not harmful and can in fact improve a child's digestive and/or immune system. It is also important to note that some vaginal bacteria can be passed on to the baby, occasionally causing illness. Ultimately, it is a woman's decision, but as healthcare professionals we must advise our patients about the balance of unproven benefit and the small possible risks involved."

Ultimately much more research needs to be carried out into vaginal seeding to show whether it is safe and, if so, how much of a positive impact it has on the newborn's health.

Breastfeeding and antibiotic use are also known to alter the microbiota so any mums who are concerned about their baby having a healthy microbiota may do better to focus on breastfeeding and avoiding unnecessary antibiotic exposure during pregnancy.

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