Exploring Insights Into Vaginal Microbiome Profiles in Relation to Intrauterine Insemination Success Rates

Background: The vaginal microbiome has an essential role in female reproduction, especially during assisted reproduction treatments. The objective of the study was to examine vaginal microbiome profiles of women following intrauterine insemination (IUI) procedures and determine how they relate to clinical pregnancy outcomes. Materials and methods: A prospective observational study was conducted on 100 women with IUI treatment. Before the procedure, vaginal swabs were taken and sequenced using the 16S rRNA gene to determine microbial community types. Based on microbiome profiles, patients were divided into Lactobacillus-dominant (n = 68) and non-Lactobacillus-dominant (n = 32) groups. Clinical pregnancy rates were compared between the two groups. SPSS Statistics version 26.0 (IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp.) was used, with p < 0.05 considered statistically significant. Results: Overall, 68% of the participants had Lactobacillus-dominant vaginal microbiomes, whereas 32% had varied non-Lactobacillus profiles. The rate of clinical pregnancy was significantly improved in the Lactobacillus-dominant group compared to the non-dominant group, 26 (38.2%) vs. 4 (12.5%), p = 0.008. Logistic regression analysis revealed that the Lactobacillus-dominant profile was independently associated with the success of IUI (adjusted OR 3.85; 95% CI 1.28-11.58; p = 0.016). There were no significant differences in age, body mass index, and infertility duration between the two groups. Conclusions: The success rates of IUI were significantly associated with vaginal microbiome composition, particularly the predominance of Lactobacillus. These results support that microbiome profiling may become a helpful technique to predict and enhance the success rates in fertility treatment.