The Association between Vaginal Dysbiosis and Reproductive Outcomes in Sub-Fertile Women Undergoing IVF-Treatment: A Systematic PRISMA Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of clinical observational studies
PubMed 33806442 · doi:10.3390/pathogens10030295
What was done
A systematic review and meta-analysis following PRISMA guidelines included 17 studies comprising 3,543 sub-fertile women undergoing IVF treatment. The authors investigated the association between vaginal dysbiosis, defined by either microscopy or molecular methods (qPCR and NGS), and reproductive outcomes in women undergoing IVF.
What was found
Vaginal dysbiosis had an overall prevalence of 18% (95% CI 17-19). Across all diagnostic methods, vaginal dysbiosis was a significant risk factor for early pregnancy loss (RR = 1.71, 95% CI 1.29-2.27). A predefined sub-analysis of studies using molecular methods showed a significant reduction in clinical pregnancy rate compared to normal vaginal microbiota (RR = 0.55, 95% CI 0.32-0.93). Across all diagnostic methodologies, vaginal dysbiosis did not significantly influence live birth rate.
Why it matters
This review shows that molecular tools can detect subtle vaginal dysbiosis linked to early pregnancy failure in IVF patients, though live birth rates remain unaffected.
Limits
The quality of evidence across all reproductive outcomes was rated very low by GRADE criteria. The included studies relied on observational cohorts with varying diagnostic criteria, and no effect on live birth rates was demonstrated.
Cited by
- partial A healthy, Lactobacillus-dominated vaginal microbiome without dysbiosis is associated with a shorter time to conceive, successful embryo implantation, and improved IVF success rates.