The dynamics of the vaginal microbiome during infertility therapy with in vitro fertilization-embryo transfer

J Assist Reprod Genet. 2012 Feb;29(2):105-15. doi: 10.1007/s10815-011-9694-6. Epub 2012 Jan 6.


Purpose: To determine the vaginal microbiome in women undergoing IVF-ET and investigate correlations with clinical outcomes.

Methods: Thirty patients had blood drawn for estradiol (E(2)) and progesterone (P(4)) at four time points during the IVF-ET cycle and at 4-6 weeks of gestation, if pregnant. Vaginal swabs were obtained in different hormonal milieu, and the vaginal microbiome determined by deep sequencing of the 16S ribosomal RNA gene.

Results: The vaginal microbiome underwent a transition during therapy in some but not all patients. Novel bacteria were found in 33% of women tested during the treatment cycle, but not at 6-8 weeks of gestation. Diversity of species varied across different hormonal milieu, and on the day of embryo transfer correlated with outcome (live birth/no live birth). The species diversity index distinguished women who had a live birth from those who did not.

Conclusions: This metagenomics approach has enabled discovery of novel, previously unidentified bacterial species in the human vagina in different hormonal milieu and supports a shift in the vaginal microbiome during IVF-ET therapy using standard protocols. Furthermore, the data suggest that the vaginal microbiome on the day of embryo transfer affects pregnancy outcome.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Bacteria / classification*
  • Embryo Transfer
  • Estradiol / blood
  • Female
  • Fertilization in Vitro*
  • Humans
  • Metagenome*
  • Middle Aged
  • Pregnancy
  • Pregnancy Outcome
  • Progesterone / blood
  • RNA, Ribosomal, 16S / genetics*
  • Vagina / microbiology*


  • RNA, Ribosomal, 16S
  • Progesterone
  • Estradiol