Diagnosis of Chronic Endometritis in Endometrial Fluid Using Molecular Techniques to Improve the Outcomes of Assisted Reproductive Treatments

Study Overview
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Brief Summary
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Chronic endometritis (CE) is a persistent inflammation of the endometrial lining caused by the infection of the uterine cavity mainly by bacterial pathogens. It is known that CE can produce implantation failure, recurrent abortion and preterm labor. The study hypothesis is that patients who have repeated implantation failures (RIF) despite transferring good quality and normal embryos, diagnosed by preimplantation Genetic Diagnosis (PGD), into a receptive endometrium, diagnosed by Endometrial Receptivity Analysis (ERA), may present asymptomatic CE, being the altered endometrium the main cause of these implantation failures. The current diagnosis of CE is the microbiological culture of endometrial biopsy samples. Alternatively, examination of the uterine cavity by hysteroscopy is effective at 93.4%. However, both methods have limitations, such as the time needed to obtain the diagnosis, the economic cost of the tests, the possibility of detecting microorganisms in culture etc. For these reasons, the developing of a simple, fast, cheap and minimally invasive diagnostic tool for CE patients subjected to IVF treatments is expected. It would be very useful in order to establish a specific treatment and improve pregnancy rates in infertile patients. For this reason, the bacterial DNA present in the endometrial fluid samples will be obtained and the identification of the causative pathogens of CE will be done by sequencing (NGS) and/or quantitative PCR with specific oligonucleotides for the most common bacteria causing CE. The validation of this new method will be performed by comparison with the microbiological diagnosis of those same patients.

Detailed Description
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On day 5 of the Hormonal Replacement Therapy (after 5 days of progesterone administration), coinciding with the day of hysteroscopy indicated by the physician according to the routine clinical practice, samples of endometrial fluid (EF) and endometrial biopsy (EB) of patients with RIF will be obtained. These samples will be used for the diagnosis of CE by both classic and molecular methods. Specifically, EF sample will be analyzed by molecular techniques using Next Generation Sequencing (NGS) for the detection of infectious agents. EB sample will be divided into three parts, one of them will be used for molecular analysis (as control of the bacterial content present in the EF), another part will be subjected to microbiological analysis and the third part will be analyzed using histological techniques. In this way, comparisons will be made between the different diagnostic methods of CE in the two sample types (EF and EB) and the efficacy values of the new diagnostic test (sensitivity, specificity, positive and negative predictive values and Receiving Operating Characteristic curves) will be obtained using the microbiological diagnosis as a reference (gold standard method). Patients with a negative outcome for CE (approximately 40%) will continue with the expected assisted reproduction treatment (ART) according to the clinic's standard protocol and patients with a positive outcome for CE (approx. 60%) will receive antibiotic treatment according to usual clinical practice (time and type of antibiotic will be different according to the microbiological diagnosis). Once this treatment is completed, the improvement of these patients will be confirmed obtaining a second sample of EF and EB. The Assisted Reproductive Treatment (ART) will be performed once the specialist considers it appropriated. Finally, reproductive rates will be correlated with the diagnosis of CE. Therefore, an observational analytical study, in which a comparison of the ART results before and after its diagnosis of CE, will be carried out. The reproductive impact of an altered endometrial microbiota will be assessed analyzing the implantation rates, pregnancy and ongoing pregnancy.

Official Title
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Diagnosis of Chronic Endometritis in Endometrial Fluid Using Molecular Techniques to Improve the Outcomes of Assisted Reproductive Treatments

Conditions
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Chronic Endometritis

Intervention / Treatment
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* Procedure: Endometrial Biopsy and endometrial fluid collection


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients who provide their written informed consent after having been informed of the all study aspects. IVF or ICSI cycles with own oocytes, with blastocyst transfer (day 5 or 6 of stage development). Women with age comprised between 18 and 38 years (both included). Body mass index: 18.5 - 30 km/m2 (both included) Adequate ovarian reserve > 8 antral follicles (RFA) and/or Antimüllerian hormone (HAM)> 1 ng / mL. Concentration of spermatozoa > 2 million sperm/ml. Exclusion Criteria: Congenital or acquired uterine pathologies. Endometriosis. Patients with IUDs in the last 3 months. Patients who have taken prescribed antibiotic treatment in the last 3 months. Any disease or medical condition that could be unstable or could endanger the security of the patient and her compliance in the study.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 38 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with RIF<br>Patients with repeated implantation failure (RIF) with indication of hysteroscopy within normal clinical practice, who will undergo FIV or ICSI and embryo transfer within their assisted reproduction treatment (ART). | Procedure: Endometrial Biopsy and endometrial fluid collection<br>* On day 5 of the Hormonal Replacement Therapy (after 5 days of progesterone administration), the doctor will perform endometrial fluid aspiration (EF) followed by an endometrial biopsy (EB) the same day of hysteroscopy that is performed as usual clinical practice. EF sample will be analyzed by molecular techniques (Next Generation Sequencing) for the detection of infectious agents and the EB sample will be divided into three parts, one of them will be used for molecular analysis (as control of the bacterial content present in the EF) and the others will be used for microbiological analysis and histological techniques respectively. The Assisted Reproductive Treatment (ART) will be performed once the specialist considers it appropriated according to the clinical standard practice and the reproductive rates will be correlated with the diagnosis of CE comparing the results of ART before and after its diagnosis of CE.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Developing of a new non invasive diagnosis test by Next Generation Sequencing (NGS) analysis for patients diagnosed with chronic endometritis (CE). | DNA analysis by NGS using endometrial fluid for the CE diagnose. | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To compare the diagnose of CE, determined by classical and molecular methods measured by NGS, in both types of samples analyzed (endometrial fluid and endometrial biopsy). | Endometrial fluid will be used for the DNA analysis by NGS and endometrial biopsy will be used for the classical diagnosis ((microbial culture, histology and hysteroscopy). | 24 months | 
| Qualitative study of the endometrial microbiome by classical and molecular methods in order to determine their influence in the CE diagnose. | To determine the identity of pathogenic bacteria measured by NGS that could establish endometrial infection. | 24 months | 
| Quantitative study of the endometrial microbiome by classical and molecular methods in order to determine their influence in the CE diagnose. | To determine the minimal amount of pathogenic bacteria measured by NGS that could establish endometrial infection. | 24 months | 
| Relationship between the implantation rate and the diagnosis of CE, by molecular and classical methods, in patients undergoing assisted reproduction treatments (ART). | Implantation rate is defined as the number of gestational sacs observed by vaginal ultrasound per number of transferred embryos in the 6th gestational week. | 6 weeks | 
| Relationship between the ongoing pregnancy rate per embryo transfer and the diagnosis of CE, by molecular and classical methods, in patients undergoing assisted reproduction treatments (ART). | Ongoing pregnancy rate is defined as the number of ongoing pregnancies after the 20th gestational week per total number of embryo transfers performed. | 5 months | 
| Relationship between the live birth rate and the diagnosis of CE, by molecular and classical methods, in patients undergoing assisted reproduction treatments (ART). | Live birth rate is defined as the number of the total live births per total number of embryo transfers performed. | 9 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic Endometritis, Endometrial pathogens, Microbiological diagnosis, Next Generation Sequencing, Metagenomics, Endometrial receptivity