Abstract
Purpose
To investigate if the vaginal microbiome influences the IVF outcome.
Methods
Thirty-one patients undergoing assisted reproductive treatment (ART) with own or donated gametes and with cryotransfer of a single euploid blastocyst were recruited for this cohort study. Two vaginal samples were taken during the embryo transfer procedure, just before transferring the embryo. The V3 V4 region of 16S rRNA was used to analyze the vaginal microbiome, and the bioinformatic analysis was performed using QIIME2, Bioconductor Phyloseq, and MicrobiomeAnalyst packages. Alpha diversity was compared between groups according to the result of the pregnancy test.
Results
Fourteen (45.2%) patients did not and seventeen (54.8 %) did achieve pregnancy under ART. A greater index of alpha diversity was found in patients who did not achieve pregnancy comparing to those who did, although this difference was not significant (p = 0.088). In the analysis of beta diversity, no statistically significant differences were observed between groups established as per the pregnancy status. Samples from women who achieved pregnancy showed a greater presence of Lactobacillus spp. The cluster analysis identified two main clusters: the first encompassed the genera Lactobacillus, Gardnerella, Clostridium, Staphylococcus, and Dialister, and the second included all other genera. Women who achieved pregnancy were mainly detected microorganisms from the first cluster.
Conclusions
The vaginal microbiome can influence the results of ART. The profiles dominated by Lactobacillus were associated with the achievement of pregnancy, and there was a relationship between the stability of the vaginal microbiome and the achievement of pregnancy.





References
Peñalver Bernabé B, Cralle L, Gilbert JA. Systems biology of the human microbiome. Curr Opin Biotechnol. 2018;51:146–53.
Witkin SS, Linhares IM, Giraldo P. Bacterial flora of the female genital tract: function and immune regulation. Best Pract Res Clin Obstet Gynaecol. 2007;21(3):347–54.
Mascarenhas MN, Flaxman SR, Boerma T, Vanderpoel S, Stevens GA. National, regional, and global trends in infertility prevalence since 1990: a systematic analysis of 277 health surveys. PLoS Med. 2012;9:e1001356.
Lambert JA, John S, Sobel JD, Akins RA. Longitudinal analysis of vaginal microbiome dynamics in women with recurrent bacterial vaginosis: recognition of the conversion process. PLoS One. 2013;8(12):e82599.
Ralph SG, Rutherford AJ, Wilson JD. Influence of bacterial vaginosis on conception and miscarriage in the first trimester: cohort study. BMJ. 1999;319(7204):220–3.
Haahr T, Zacho J, Bräuner M, Shathmigha K, Skov Jensen J, Humaidan P. Reproductive outcome of patients undergoing in vitro fertilization treatment and diagnosed with bacterial vaginosis or abnormal vaginal microbiota: a systematic PRISMA review and meta-analysis. BJOG. 2018.
van Oostrum N, De Sutter P, Meys J, Verstraelen H. Risks associated with bacterial vaginosis in infertility patients: a systematic review and meta-analysis. Hum Reprod. 2013a;28(7):1809–15.
Romero R, Hassan SS, Gajer P, Tarca AL, Fadrosh DW, Nikita L, et al. The composition and stability of the vaginal microbiota of normal pregnant women is different from that of non-pregnant women. Microbiome. 2014;2(1):4.
Graspeuntner S, Bohlmann MK, Gillmann K, Speer R, Kuenzel S, Mark H, et al. Microbiota-based analysis reveals specific bacterial traits and a novel strategy for the diagnosis of infectious infertility. PLoS One. 2018;13(1):e0191047.
Kyono K, Hashimoto T, Nagai Y, Sakuraba Y. Analysis of endometrial microbiota by 16S ribosomal RNA gene sequencing among infertile patients: a single-center pilot study. Reprod Med Biol. 2018;17:297–306.
Singer M, Borg M, Ouburg S, Morré SA. The relation of the vaginal microbiota to early pregnancy development during in vitro fertilization treatment—a meta-analysis. J Gynecol Obstet Hum Reprod. 2019a;48(4):223–9. https://doi.org/10.1016/j.jogoh.2019.01.007 Review.
Bracewell-Milnes T, Saso S, Nikolaou D, Norman-Taylor J, Johnson M, Thum MY. Investigating the effect of an abnormal cervico-vaginal and endometrial microbiome on assisted reproductive technologies: a systematic review. Am J Reprod Immunol. 2018;80(5):e13037. https://doi.org/10.1111/aji.13037 Review.
Kroon SJ, Ravel J, Huston WM. Cervicovaginal microbiota, women’s health, and reproductive outcomes. Fertil Steril. 2018;110(3):327–36. https://doi.org/10.1016/j.fertnstert.2018.06.036 Review.
Lawley B, Tannock GW. Analysis of 16S rRNA gene amplicon sequences using the QIIME software package. Methods Mol Biol. 2017;1537:153–63.
Kuczynski J, Stombaugh J, Walters WA, González A, Caporaso JG, Knight R. Using QIIME to analyze 16S rRNA gene sequences from microbial communities. Curr Protoc Microbiol. 2012; Chapter 1:Unit 1E.5.
McMurdie PJ, Holmes S. phyloseq: an R package for reproducible interactive analysis and graphics of microbiome census data. PLoS ONE. 2013;8(4):e61217.
Dhariwal A, Chong J, Habib S, King I, Agellon LB, Xia J. MicrobiomeAnalyst - a web-based tool for comprehensive statistical, visual and meta-analysis of microbiome data. Nucleic Acids Res. 2017;45:W180–8.
MacIntyre DA, Chandiramani M, Lee YS, Kindinger L, Smith A, Angelopoulos N, et al. The vaginal microbiome during pregnancy and the postpartum period in a European population. Sci Rep. 2015;5:8988.
Subramaniam A, Kumar R, Cliver SP, Zhi D, Szychowski JM, Abramovici A, et al. Vaginal microbiota in pregnancy: evaluation based on vaginal flora, birth outcome, and race. Am J Perinatol. 2016;33(4):401–8.
Aagaard K, Riehle K, Ma J, Segata N, Mistretta TA, Coarfa C, et al. A metagenomic approach to characterization of the vaginal microbiome signature in pregnancy. PLoS One. 2012;7(6):e36466.
Ravel J, Gajer P, Abdo Z, Schneider GM, Koenig SS, McCulle SL, et al. Vaginal microbiome of reproductive-age women. Proc Natl Acad Sci U S A. 2011;108(Suppl 1):4680–7.
Moreno I, Codoñer FM, Vilella F, Valbuena D, Martinez-Blanch JF, Jimenez-Almazán J, et al. Evidence that the endometrial microbiota has an effect on implantation success or failure. Am J Obstet Gynecol. 2016;215(6):684–703.
Walther-António MR, Jeraldo P, Berg Miller ME, Yeoman CJ, Nelson KE, Wilson BA, et al. Pregnancy's stronghold on the vaginal microbiome. PLoS One. 2014;9(6):e98514.
Miller EA, Beasley DAE, Dunn RR, Archie EA. Lactobacilli dominance and vaginal pH: why is the human vaginal microbiome unique? Front Microbiol. 2016;7:1936.
Kyono K, Hashimoto T, Kikuchi S, Nagai Y, Sakuraba Y. A pilot study and case reports on endometrial microbiota and pregnancy outcome: an analysis using 16S rRNA gene sequencing among IVF patients, and trial therapeutic intervention for dysbiotic endometrium. Reprod Med Biol. 2019;18:72–82.
Maduka RN, Osaikhuwuomwan JA, Aziken ME. The effect of bacterial colonization of the embryo transfer catheter on outcome of in vitro fertilization–embryo transfer treatment. Afr J Med Health Sci. 2018;17(1):7–13.
Selman H, Mariani M, Barnocchi N, Mencacci A, Bistoni F, Arena S, et al. Examination of bacterial contamination at the time of embryo transfer, and its impact on the IVF/pregnancy outcome. J Assist Reprod Genet. 2007;24(9):395–9. https://doi.org/10.1007/s10815-007-9146-5.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest.
Informed consent
Informed consent was obtained from all individual participants included in the study.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Electronic supplementary material
ESM 1
(DOCX 11 kb)
Rights and permissions
About this article
Cite this article
Bernabeu, A., Lledo, B., Díaz, M.C. et al. Effect of the vaginal microbiome on the pregnancy rate in women receiving assisted reproductive treatment. J Assist Reprod Genet 36, 2111–2119 (2019). https://doi.org/10.1007/s10815-019-01564-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10815-019-01564-0