Effect of Anticoagulant Therapy on Endometrial Receptivity and Pregnancy Outcomes in Infertility

March 20, 2026 updated by: zhangli, Tang-Du Hospital

Evaluation of the Effect of Anticoagulant Therapy on Endometrial Receptivity and Pregnancy Outcomes in Patients With Infertility Using an Ultrasound Multimodal System

The purpose of this prospective observational cohort study is to evaluate the effect of routine clinical anticoagulant therapy on endometrial receptivity and subsequent pregnancy outcomes in women with infertility. Researchers will utilize an ultrasound multimodal system to systematically assess endometrial parameters, including thickness, morphology, peristalsis, and blood flow indices. The study aims to enroll approximately 300 infertile women aged 20 to 45 years. Participants will be observed and grouped based on whether they receive anticoagulant medications, such as aspirin or heparin sodium, as part of their standard clinical care. The study will track ultrasound-based receptivity indicators and follow up on pregnancy status and outcomes at 45 and 90 days of gestation. This study is purely observational, and all clinical treatment decisions are made independently of the study protocol.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Background and Rationale:

Endometrial receptivity plays a pivotal role in the success of embryo implantation for patients with infertility. Impaired endometrial perfusion is considered a significant contributing factor to implantation failure. In routine clinical practice, anticoagulant therapies, such as low-dose aspirin and low molecular weight heparin (e.g., heparin sodium), are frequently utilized to improve local hemodynamics and endometrial receptivity. However, a systematic, non-invasive, and quantitative evaluation of these therapeutic effects on the endometrium is still required.

Multimodal ultrasound provides a comprehensive, real-time, and non-invasive approach to assessing endometrial dynamics. By integrating conventional 2D ultrasound, 3D ultrasound, and Doppler imaging, this technology can meticulously quantify endometrial parameters, offering valuable predictive insights for clinical pregnancy outcomes.

Study Design and Methodology:

This is a single-center, prospective, observational cohort study. The objective is to evaluate the impact of routine anticoagulant therapy on endometrial receptivity and subsequent pregnancy outcomes in infertile women using an ultrasound multimodal system.

The study plans to enroll approximately 300 eligible infertile women aged 20 to 45 years. Participants will be categorized into two observational cohorts based solely on their routine clinical care plans:

Observation Group: Patients receiving anticoagulant therapy (e.g., aspirin, heparin sodium) in addition to conventional treatment.

Control/Comparison Group: Patients receiving conventional treatment only. Note: The decision to administer anticoagulant therapy is entirely at the discretion of the attending physicians based on clinical indications, independent of this study protocol. This study is strictly observational and involves no protocol-driven interventions.

Data Collection and Assessments:

During the clinically defined window of implantation, all participants will undergo comprehensive multimodal ultrasound examinations. The primary ultrasonographic parameters to be recorded include:

Endometrial thickness and morphological patterns.

Endometrial peristalsis characteristics.

Endometrial and subendometrial blood flow indices, including Vascularization Index (VI), Flow Index (FI), and Vascularization Flow Index (VFI) via 3D power Doppler.

Follow-up and Endpoints:

Following the ultrasound assessments and embryo transfer/conception, participants will be longitudinally followed. The clinical endpoints, specifically the pregnancy status and outcomes, will be rigorously tracked and documented at 45 days and 90 days of gestation. The collected data will be analyzed to determine the correlation between the multimodal ultrasound parameters of endometrial receptivity under anticoagulant therapy and the ultimate pregnancy success rates.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • China
    • Shaanxi
      • Xi'an, Shaanxi, China, 710038

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population consists of adult female patients, aged 20 to 45 years, who have been clinically diagnosed with infertility. These patients are seeking routine infertility treatments, such as in vitro fertilization (IVF) and embryo transfer or monitored conception cycles, at Tangdu Hospital. The population includes patients who receive standard conventional treatment as well as those who are prescribed adjunctive anticoagulant therapy based on their routine clinical care indications.

Description

Inclusion Criteria:

  • Female patients aged 20 to 45 years.

Clinically diagnosed with infertility and planning to undergo embryo transfer or monitored conception cycles.

Patients who have complete baseline clinical data and are willing to undergo multimodal ultrasound evaluation of endometrial receptivity during the window of implantation.

Voluntarily agreed to participate in this observational study and signed the informed consent form for data collection.

Exclusion Criteria:

  • Presence of congenital uterine malformations (e.g., septate uterus, bicornuate uterus, unicornuate uterus) that significantly alter the endometrial cavity.

Presence of untreated severe intrauterine lesions, such as submucosal fibroids, severe intrauterine adhesions, or endometrial polyps that may mechanically interfere with implantation.

Severe underlying systemic diseases, including but not limited to severe liver or kidney dysfunction, or malignant tumors.

Known severe bleeding disorders or strict contraindications to anticoagulant medications (for patients in the routine clinical care setting).

Patients who are unable to cooperate with the transvaginal multimodal ultrasound examination or complete the required follow-up for pregnancy outcomes.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Anticoagulant Therapy Cohort
Patients in this cohort receive routine clinical anticoagulant therapies (such as low-dose aspirin or low molecular weight heparin) in addition to their conventional infertility treatment. The use of anticoagulants is determined by the attending physician based on standard clinical indications, strictly independent of this observational study protocol.
Drug: Routine Anticoagulant Therapy (Aspirin or Heparin Sodium)
Patients receive low-dose aspirin or low molecular weight heparin (e.g., heparin sodium) purely as part of their standard clinical care. The decision to initiate, adjust, or terminate this therapy is made entirely by the attending physician based on clinical indications, strictly independent of this observational study protocol. This is tracked solely as an observational exposure.
Conventional Treatment Cohort
Patients in this cohort receive conventional infertility treatment only, without the addition of anticoagulant therapies, as per standard clinical practice.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Clinical Pregnancy Rate
Time Frame: Up to 90 days of gestation
The clinical pregnancy rate is defined as the proportion of patients with the presence of at least one intrauterine gestational sac with a visible fetal heartbeat, confirmed by transvaginal ultrasound.
Up to 90 days of gestation

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Endometrial Thickness
Time Frame: During the window of implantation (prior to embryo transfer)
The maximum anteroposterior diameter of the endometrium measured in millimeters (mm) in the midsagittal plane using 2D transvaginal ultrasound.
During the window of implantation (prior to embryo transfer)
Endometrial Morphological Pattern
Time Frame: During the window of implantation (prior to embryo transfer)
Evaluated via 2D transvaginal ultrasound and classified into three typical patterns: Type A (triple-line pattern), Type B (intermediate isoechogenic pattern), and Type C (homogeneous hyperechogenic pattern) to assess morphological receptivity.
During the window of implantation (prior to embryo transfer)
Endometrial and Subendometrial Blood Flow Indices
Time Frame: During the window of implantation (prior to embryo transfer)
Quantitative assessment of local tissue perfusion using 3D power Doppler ultrasound. The parameters measured include Vascularization Index (VI, reflecting vessel density), Flow Index (FI, reflecting blood flow intensity), and Vascularization Flow Index (VFI, a combination of vascularity and flow intensity).
During the window of implantation (prior to embryo transfer)
Endometrial Peristalsis Frequency
Time Frame: During the window of implantation (prior to embryo transfer)
The frequency of endometrial wave-like activity (contractions per minute) observed via continuous transvaginal ultrasound scanning for a duration of 3 to 5 minutes.
During the window of implantation (prior to embryo transfer)
Early Miscarriage Rate
Time Frame: Up to 90 days of gestation
The proportion of patients who experience a spontaneous pregnancy loss after the initial ultrasound confirmation of an intrauterine clinical pregnancy, prior to 90 days of gestation.
Up to 90 days of gestation

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tang-Du Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Li Zhang, MD, Tang-Du Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 30, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 20, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 20, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 27, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
March 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 20, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • K202508-28

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data (IPD) underlying the results reported in the published article will be shared. Data will be available to researchers who provide a methodologically sound proposal, purely for the purpose of achieving the aims in the approved proposal.

IPD Sharing Time Frame

Data will be available beginning 6 months and ending 36 months following article publication.

IPD Sharing Access Criteria

To gain access, data requestors will need to contact the corresponding author and sign a formal data access agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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