The birthing trend for babies born by C-section has some experts concerned about health risks.

vaginal seeding
Credit: Phattana Stock/Shutterstock

Many birthing trends that aim to be more "natural" have advantages for mom and Baby. But Ob-Gyns are now warning pregnant women against one known as "vaginal seeding," the process of swabbing a baby born via C-section with its mom's vaginal secretions. Some say this exposure to the bacteria in vaginal fluid can help strengthen the immune system, but doctors say it could put newborns at risk of infection. Are the real risks worth the unproven benefits?

What is Vaginal Seeding?

It sounds kind of gross, but when you think about how babies are born, you realize they are exposed to mom's vaginal secretions as they travel the birth canal. C-section babies miss out on this process, so vaginal seeding seeks to rectify it by swabbing the baby's mouth, nose, and skin with vaginal fluids. "The theory is that exposing the infant to beneficial bacteria naturally present in the birth canal decreases the risk of allergies, asthma, and autoimmune diseases when the baby is delivered by cesarean instead of vaginally," Clara Ward, M.D., a maternal-fetal medicine specialist at McGovern Medical School at UTHealth and Children's Memorial Hermann Hospital in Houston, tells "These disorders are less common in women who deliver vaginally, possibly due to exposure to organisms in the birth canal during delivery."

It's all about the gut microbiome, the collection of "good" bacteria that live in the intestines and help regulate our immune response to bad bacteria. Some research has suggested that vaginal secretions lead to a different (and possibly healthier) gut microbiome for babies than those born by C-section. But although there is a link between allergies, asthma, autoimmune disease, obesity, and C-sections, cause and effect has not actually been proven.

In addition, "there are very few studies so far examining vaginal seeding with too few infants to say that it is effective," Dr. Ward says. "At this point there is not enough data to say that it is beneficial or harmful."

OK, but if it's natural it can't be bad, right? Not exactly. "While the practice seems to make sense biologically, it is also theoretically possible to transfer harmful bacteria, which could lead to serious infections, particularly in preterm babies," Dr. Ward says.

The Risks of Vaginal Seeding

Following this cautionary approach, the American College of Obstetricians and Gynecologists (ACOG) issued a November 2017 statement advising against vaginal seeding until more data becomes available. "When a procedure has no proven benefit, care must be taken to make sure harm is not caused," Dr. Ward says. "At this point, more research needs to be done to confirm that the practice is safe and beneficial."

Infections that could be passed along include Group B strep and sexually transmitted diseases like herpes, gonorrhea and chlamydia. Although women may be screened for some of these infections prior to giving birth, it would be difficult to catch all cases. It's true that babies born vaginally are also exposed to these risks, but doctors still don't want to raise the chance of infection for C-section babies without a proven benefit. Plus, vaginal seeding might not exactly replicate nature, in which there would be other substances, like blood and amniotic fluid, to dilute the vaginal secretions.

Even if you don't think you have any infections, vaginal seeding may be too risky to try—especially without your doctor's okay. Instead, if you want your C-section baby to receive gut health benefits, Dr. Ward has other recommendations: "Early establishment of breastfeeding and skin-to-skin contact is a great way to give your baby many beneficial substances, including antibody protection and beneficial bacteria."