Is a foetus developing in a sterile environment?

Lett Appl Microbiol. 2014 Dec;59(6):572-9. doi: 10.1111/lam.12334. Epub 2014 Oct 27.


Novel findings in microbiology question the long-standing paradigm that a healthy pregnancy implies a sterile uterus. It now seems that the placenta is frequently colonized with bacteria, and a placental microbiome has been identified. Recent literature findings are summarized here, and an attempt is made to separate pathological bacterial presence from a naturally occurring microbiome.

Keywords: amniotic fluid; breast milk; neonatal sepsis; newborn colonization; placenta microbiome; placental microbiome; preterm birth.

Publication types

  • Review

MeSH terms

  • Amniotic Fluid / microbiology
  • Bacteria / growth & development*
  • Bacteria / isolation & purification*
  • Bacterial Infections / microbiology*
  • Female
  • Fetal Development
  • Fetus / microbiology*
  • Humans
  • Infant
  • Microbiota*
  • Placenta / microbiology*
  • Pregnancy
  • Pregnancy Complications, Infectious / microbiology
  • Premature Birth / etiology