Germ-wise, the common belief and understanding is that the uterus is a mostly clean and sterile space. However, a recent study by a group of Australian researchers from Edith Cowan University and the University of Western Australia has proven otherwise.
The research studied placentas, amniotic fluid, and babies' first poop in order to reach their conclusions.
The trickiest part of the study was ensuring that microbes isolated in those cases were not simply contaminants. The researchers took extra care when running tests in order to ensure the microflora they discovered could only have appeared from one specific place.
Reproductive Biologist, Lisa Stinson said "Over the last decade, numerous studies have detected bacterial DNA in amniotic fluid and first-pass meconium (baby's first poop), challenging the long-held assumption that the womb is sterile."
Stinson continued, "However, some argue that the results are false positives – contaminants in the reagents used in DNA analysis."
Clean as a whistle
Stinson and her team ensured no stray bacteria could muddy their samples prior to extraction.
To keep the risk of any extra contaminents to a minumum, the team took samples from 43 different women who gave birth via C-section, or caesarian section. Ten millilitres of amniotic fluid were collected straight after the incision and placed into sterilized tubes.
The next day they collected 50 specimens of meconium from the babies. An enzyme was then used on any stray bacterial DNA.
Even with these specific precautions, bacterial DNA was still found in "almost all samples," Stinson states.
Healthy dose of microbes from birth canal could be a myth
As the story goes, it's been long believed that newborns get their dose of first microbes from the birth canal, right as they squeeze through. Those born by caesarian section are even given a swab with a 'seed' of vaginal fluids to set them on their healthy way into life on earth.
Recent research may disprove this, however, as there is no sound evidence to be found.
From this study, it is slowly becoming clearer that babies may already have some of these microbes before being born - as these microbes have been discovered on newborns' skin and in their guts prior to birth.
The research is not finished yet, as Stinson points out:
"Here we've proven that bacterial DNA is present in the womb, but the next step will be to show whether these are alive and constitute a true microbiome."
If this is true, microbes could well be shaping the path of our development from our very first moments in life.