IVF/ICSI Success Rates and the Infectious Factor: Is There a Connection?

This is perhaps one of the most widely discussed and debated questions in reproductive medicine. Seeking to move closer to an answer based on the results of their own research, physicians from leading Austrian clinics specializing in assisted reproductive technologies (ART), together with specialists from DNA-Technology, undertook a dedicated study. Follicular fluid samples from 24 women undergoing IVF/ICSI procedures were selected for analysis, and the microbial spectrum was assessed using the FEMOFLOR®16 and ANDROFLOR®. It was found that the absence of bacterial DNA correlates with a high probability of successful fertilization. The key role in predicting ART outcomes appears to belong to the overall microbial impact leading to disruption of the dynamic balance of the microbiota.

This study focuses on investigating the role of the microbial component of ovarian follicular fluid in the effectiveness of assisted reproductive technology (ART) programs. Microbiological analysis was performed using the commercial FEMOFLOR®16 and ANDROFLOR® real-time PCR assays on the DTprime 5M1 real-time PCR instrument, manufactured by DNA-Technology.The relevance of this research lies in the persistent limitations of ART success rates despite significant technological progress in embryology. In a substantial number of cases, the causes of failed fertilization remain unclear even when morphological, clinical, and laboratory parameters are normal. Studying the follicular microenvironment, including its microbial component, represents a promising direction in the search for new biomarkers of oocyte quality and factors influencing reproductive outcomes.

The authors examine the hypothesis that local microbial contamination of the follicle may affect the functional competence of the oocyte and its capacity for fertilization. Unlike previous studies, this research analyzed two follicles from each patient, making it possible to minimize inter-patient variability and identify local effects within a specific follicle.

The key finding was the identification of a strong correlation between the presence of bacterial DNA in the follicle (increased total bacterial load, TBL) and failure of in vitro fertilization. Conversely, the absence of bacterial DNA was associated with a high likelihood of successful fertilization (classification accuracy approximately 85%). No specific microorganisms were identified as directly influencing the outcome. Most likely, the decisive factor is the total microbial load or a dysbiotic state.

The study also demonstrates pronounced microbiome heterogeneity even between follicles of the same patient, indicating the local (microecological) nature of microbial influence. Proposed mechanisms include inflammatory changes, impaired granulosa cell function, and disruption of the hormonal regulation of oocyte maturation.

This work supports the concept that the follicular fluid microbiome is involved in the regulation of fertility and raises the possibility of its future use as a biomarker of ART effectiveness. At the same time, it underscores the need for further studies to identify specific molecular mechanisms.

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