Clinical trial NCT06920797: New Strategies to Evaluate the Reproductive Tract Microbiome
Official title: Evaluation of New Strategies in the Analysis of the Reproductive Tract Microbiome: A Descriptive Pilot Study
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Fertility
Infertility
Reproductive Health
Microbiome Analysis
Keywords: endometrial microbiome
Microbiome
Reproductive tract
Pathogenic bacteria
Dysbiosis
Lead sponsor: Igenomix
Sponsor class: INDUSTRY
First posted: 2025-04-10
Enrollment: 50
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Women, between 18 and 50 years, coming form the donor program and/or patients from the General Gynaecology Unit who attend to routine gynaecological controls to the clinic, and whose samples will be taken during the secretory phase of the natural menstrual cycle.

Brief summary: The goal of this observational study is to evaluate alternative less invasive sampling methods for the analysis of the endometrial microbiome. For that, vaginal swab and endometrial fluid samples will be assessed in comparison with the standard sampling method (an endometrial biopsy), in women aged 18-50 years on an oocyte donation program and/or who attend the clinic for routine gynecological controls, and whose samples will be collected during the secretory phase of a natural menstrual cycle. The study aims to:

* Evaluate the pontential of the less invasive techniques to assess the endometrial microbiome, compared to the endometrial biopsy, as well as their safety.
* Evaluate the microbiome's stability in a period of 1 to 3 months.

Participants will undergo a sampling round (of the 3 sampling methods), and then a second round 1, 2 or 3 months later, as assigned by the investigator.

Detailed description: The endometrium plays a pivotal role in reproductive health, influencing processes such as implantation and pregnancy. Although the endometrium has generally been considered a tissue free of bacteria, numerous studies have documented the presence of an endometrial microbiome mainly composed of different species from the Lactobacillus genus. The presence of pathogenic bacteria has been shown to disrupt the uterine environment, affecting implantation rates and pregnancy success.

Traditional and emerging sampling methods allow for the study of the microbial profile of the endometrium, but the efficiency and representativeness of these techniques vary. Therefore, this study aims to compare the effectiveness, accuracy, and usefulness of three different sampling methods for microbiome analysis: endometrial biopsy, endometrial fluid, and vaginal swab. Additionally, it seeks to compare the endometrial microbial profiles with the vaginal microbiome to assess whether it may provide indirect information about the upper reproductive tract.

Endometrial biopsy is a gynecological procedure routinely performed in the clinical practice to provide the patient with an analysis of their microbiome before embryo transfer, ensuring that it is carried out in a non-pathological endometrium, especially in patients with previous implantation failures. It is considered the standard for uterine lining sampling but is an invasive technique that, due to the discomfort associated with the procedure itself, may not always be feasible. Endometrial fluid is a less invasive method that offers a potential alternative by collecting cells from the endometrial surface. On the other hand, studying the vaginal microbiome, although it may provide insight into reproductive outcomes, may not accurately reflect the microbiome of the uterine cavity, a key location where implantation and pregnancy occur. By using comprehensive microbiome analysis techniques, this study will assess the microbial populations collected by each method and determine the efficiency and usefulness of each sampling technique.

Through direct comparison, this research aims to establish a clearer understanding of how sampling techniques can impact microbiome analysis in the context of reproductive health. The results obtained could have significant implications for clinical practice, potentially offering less invasive and more accurate methods to evaluate the endometrial microbiome. This study aims not only to redirect our approach to sampling the endometrial microbiome but also to improve our understanding of its role in female reproductive health. Furthermore, it would facilitate the assessment of potential correlations between the endometrial and vaginal microbiomes.

Eligibility criteria: Inclusion Criteria:

* Women, between 18 and 50 years, coming form the donor program and/or patients from the General Gynaecology Unit who attend to routine gynaecological controls to the clinic and who voluntarily accept to participate and sign the corresponding informed consent approved by the Ethics Committee, once they have been dully informed of the study's nature and knoe the potential risks, benefits and discomforts.

Exclusion Criteria:

* Ongoing pregnancy.
* Samples not obtained during the secretory phase of a natural cycle.
* Intake of any antibiotic, probiotic and/or antifungal in the 7 days prior to the sample collection of the first cycle.

Primary outcomes:
measure: Evaluation of minimally invasive techniques for the analysis of the endometrial microbiome
timeFrame: From enrollment to the second sampling round (1 to 3 months, depending on the study assigned group))
Secondary outcomes:
measure: Evaluation of the inter-cycle consistency of the microbial profile in a period of 1 to 3 months
timeFrame: From enrollment to the second sampling round (1 to 3 months, depending on the study assigned group))
measure: Safety evaluation of the sampling techniques (EB, EF and VS)
timeFrame: From enrollment to the end of the study (from 1 to 3 months, depending on the assigned group)
Other outcomes:
measure: Correlation of the VS's and EF's pH with the microbiome
timeFrame: From enrollment to the second sampling round (1 to 3 months, depending on the study assigned group))
Locations:
city: Seville
country: Spain
facility: Vida Recoletas Sevilla
Study officials:
References: