Vaginal Dysbiosis in Infertility: A Comparative Analysis Between Women with Primary and Secondary Infertility

Infertility, both primary and secondary, is strongly influenced by microbiological factors, with the vaginal microbiota playing a key role in reproductive health.

The aim of this study was to characterize the vaginal microbiota of 136 Mexican women diagnosed with infertility-primary (n = 58) and secondary (n = 78)-by evaluating the presence of pathogenic bacterial species and their associations with infertility conditions.

Samples were obtained through cervical swabs, and microorganism identification was performed using qPCR techniques.

Analysis revealed a positive correlation between increased age and the likelihood of primary infertility, as well as a negative correlation with secondary infertility. Significant differences in microbial composition were also observed between the two infertility groups. Lactobacillus crispatus and Lactobacillus gasseri were dominant in women with primary infertility, in addition to a high prevalence of Gardnerella vaginalis and Fannyhessea vaginae. Additionally, correlations were found between the presence of human papillomavirus (HPV) and sexually transmitted bacteria, as well as Gardnerella vaginalis.

Our findings suggest that the composition of the vaginal microbiota may play a decisive role in infertility, highlighting the need for personalized therapeutic strategies based on microbial profiles.