Impact of bacterial vaginosis on the reproductive outcomes of IVF: meta-analysis

Abstract

History: Bacterial vaginosis has been seen to have a negative impact on the reproductive outcomes of in vitro fertilization (IVF). Aim: To determine its impact on the rates of biochemical pregnancy, clinical pregnancy, early spontaneous miscarriage and live newborns. Data source: Bibliographic search according to PRISMA guidelines in the MEDLINE, EMBASE, CINAHL and Cochrane Library databases. Eligibility criteria for the studies: The process for identifying and selecting studies is shown in the PRISMA flowchart. Evidence was evaluated according to the GRADE method. Subjects and interventions: Infertile women with IVF. Diagnosis of bacterial vaginosis according to Nugent or qPCR criteria. Evaluation of studies and summary methods: Forest plot, sensitivity analysis, funnel plots and evaluation of evidence according to GRADE. Results: A total of seven studies were included. We detected an overall statistically significant association with the rate of biochemical pregnancy (OR 0.55; 95%CI: 0.36-0.85; P=0.004) and rate of clinical pregnancy 0.43; 95%CI: 0.22-0.87; P=0.018). This was not the case for early spontaneous miscarriage (OR 1.13; 95%CI: 0.46-2.82; P=0.78) and rate of live newborns (OR 1.63; 95%CI: 0.61- 4.32; P=0.33). Limitations: Observational studies with a small sample and significant heterogeneity between them. Conclusions: Bacterial vaginosis appears to have some impact on the rate of clinical and biochemical pregnancy achieved with IVF.