The Embryo-endometrium Multifaceted Interface: Endometrial Cavity Molecular Microbiobial and Transcriptomic Signatures in Predictinf Pregnancy Outcome in Infertile Patients Undergoing Assisted Reproduction Technology Procedures

In reproductive medicine, a fundamental challenge is to evaluate the endometrial health status during the embryo implantation window as a limiting step in predicting the success of treatments of assisted reproduction technology (ART). Some highthroughput tools, recently developed by private genomics companies, are available in the market even if they have not been independently validated and have different limitations. We propose a prospective cohort study with the aim of validating the reliability and increasing efficacy of these tools. Endometrial fluid samples will be collected non-invasively from women undergoing ART cycles and isolated genetic materials will be subjected to 16S rRNA gene sequencing for microbiota profiling and to RNAseq analysis of RNA content of extracellular vesicles previously recognized as a tissue proxy in predicting endometrial receptivity. Clinical pregnancy rate/first cycle will be the target outcome used to assess the resulting predictive models. Ultrasonographic features of the endometrium will also be collected and accounted for in the predictive model.

Study Overview

• Status: Active, not recruiting
• Conditions: Infertility (IVF Patients)

• Study Type: Observational
• Enrollment (Estimated): 322

Contacts and Locations

Study Locations

• Italy
  • Milano, Italy, 20133
    • OSR Innate Immunity and tissue remodeling Unit and Centro Scienze Natalità OS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population is composed of women undergoing assisted reproduction treatments, specifically in vitro fertilization (IVF). These patients are followed in an outpatient setting at two specialized infertility centers in Italy: San Raffaele Hospital and Fondazione Cà Granda Policlinico. They are women who have been referred to IVF due to infertility, and are starting their first IVF cycle. All participants meet specific inclusion criteria, such as being between 18 and 39 years of age, having normal uterine anatomy, and no evidence of hydrosalpinx on ultrasound examination.

The outpatient nature of the study allows for non-invasive sampling procedures and routine follow-up without the need for hospitalization. This setting reflects real-world clinical practice in reproductive medicine, ensuring that the findings will be directly applicable to standard IVF care. Additionally, the study includes a group of fertile women, also managed on an outpatient basis, who serve as a reference.

Description

IVF Patients inclusion Criteria:

• Indication to ART
• Age 18-39 years
• First ART cycle
• Normal uterine morphology and no hydrosalpinx at ultrasound

IVF Patients exclusion Criteria:

• Poor responders according to Bologna criteria
• Indications to ART for severe male infertility

Fertile Patients inclusion Criteria:

• Subjects will be cycling women with proven fertility undergoing laparoscopy for tubal ligation
• BMI < 30
• Aged 20 to 40 years

Fertile Patients exclusion Criteria:

• Smokers
• Not taking any medication

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
fertile women; Reference group
infertile women undergoing ART cycles; Cases group

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Identification of endometrial microbiome diversity	Evaluation of the endometrial microbiome composition and diversity using 16S rRNA sequencing to assess the functional impact of the endometrial microbial community in predicting the clinical pregnancy rate in women undergoing ART cycles.	through study completion, an average of 1 year
Extracellular Vesicle (EV) RNA Profiles	Quantification of extracellular vesicle (EV) RNA expression profiles from uterine fluid samples using RNA sequencing (expressed in CPM). Confirmation of the good correlation between expression of genes in tissue samples and in endometrial-derived EVs.	through study completion, an average of 1 year
Integrated Predictive Model for Clinical Pregnancy	Development of a multivariable predictive model combining endometrial microbiome diversity, EV RNA profiles, and ultrasound-AI analysis to predict clinical pregnancy rates in ART cycles.	through study completion, an average of 1 year

Collaborators and Investigators

• Sponsor: IRCCS San Raffaele
• Collaborators: Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico

Study record dates

Study Major Dates

• Study Start (Actual): January 24, 2021
• Primary Completion (Estimated): October 31, 2025
• Study Completion (Estimated): November 30, 2025

Study Registration Dates

• First Submitted: June 13, 2025
• First Submitted That Met QC Criteria: July 24, 2025
• First Posted (Actual): July 25, 2025

Study Record Updates

• Last Update Posted (Actual): July 25, 2025
• Last Update Submitted That Met QC Criteria: July 24, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Extracellular Vesicles; RNA-Seq; endometrial microbiome
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Infertility
• Other Study ID Numbers: RF-2019-12369460 (Other Grant/Funding Number: Ministry of Health (Italy))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No