What is the cause of abnormal uterine bleeding (AUB) with passage of large clots?

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Last updated: March 29, 2025View editorial policy

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From the Guidelines

Abnormal uterine bleeding (AUB) with large clots requires prompt medical attention, and the most effective treatment approach is often a combination of medical and surgical interventions, with uterine artery embolization (UAE) being a viable option for patients with bulk symptoms and heavy menstrual bleeding, as it has been shown to cause persistent decreases in pain and heavy menstrual bleeding, with an average decrease in uterine fibroid size of >50% at 5 years 1.

Initial Assessment and Treatment

When experiencing AUB with large clots, it is crucial to seek immediate medical attention, especially if soaking through pads hourly or feeling dizzy. Initial treatment may include:

  • Tranexamic acid (1000-1300 mg three times daily during bleeding) to reduce heavy menstrual bleeding
  • High-dose hormonal therapy like combined oral contraceptives (one pill three times daily for 7 days, then once daily) to stabilize the endometrium and reduce bleeding
  • IV estrogen in a hospital setting for acute heavy bleeding

Long-term Management

After stabilization, ongoing hormonal treatments such as:

  • Birth control pills
  • An IUD like Mirena
  • Non-hormonal options like NSAIDs during menstruation may be recommended. A thorough evaluation with ultrasound and possibly endometrial biopsy is essential to determine the underlying cause and guide appropriate long-term management.

Underlying Causes and Treatment Options

The passage of large clots typically indicates heavy menstrual flow where blood pools in the uterus long enough to form clots before being expelled. This can result from various causes, including:

  • Fibroids
  • Polyps
  • Adenomyosis
  • Hormonal imbalances
  • Bleeding disorders UAE has been shown to be effective in reducing heavy menstrual bleeding and improving quality of life, with lower reintervention rates compared to myomectomy 1. However, patients with no desire for future fertility should be counseled that pregnancy is possible after UAE. The choice of treatment should be individualized, taking into account the patient's symptoms, medical history, and desire for future fertility, with the goal of improving morbidity, mortality, and quality of life 1.

From the Research

Aub and Passing Large Clots

  • There are no research papers directly related to "Aub and passing large clots" in the provided evidence.
  • However, some studies discuss hemorrhage, coagulopathy, and transfusion, which may be indirectly related to the topic:
    • A study on hemostatic defects in massive transfusion 2 discusses the importance of early recognition and treatment of hemorrhage and hemostatic defects.
    • A review on tranexamic acid 3 highlights its use in reducing blood loss, transfusion rates, and bleeding-associated mortality in various clinical settings.
    • A study on management of acute upper gastrointestinal bleeding 4 recommends endoscopy, proton pump inhibitors, and transfusion as needed for resuscitation.
    • A review on massive transfusion in trauma 5 discusses the importance of early hemorrhage control, correction of metabolic derangements, and substitution of substantiated deficiencies.
  • These studies may provide some insight into the management of bleeding and coagulopathy, but they do not directly address the topic of "Aub and passing large clots".
  • A study on abdominal pain 6 discusses the challenges of diagnosing intra-abdominal pathologies, but it does not provide relevant information on the topic.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Tranexamic acid: current use in obstetrics, major orthopedic, and trauma surgery.

Canadian journal of anaesthesia = Journal canadien d'anesthesie, 2021

Research

Management of acute upper gastrointestinal bleeding.

BMJ (Clinical research ed.), 2019

Research

Massive transfusion in trauma.

Current opinion in anaesthesiology, 2024

Research

Abdominal pain: an approach to a challenging diagnosis.

AACN advanced critical care, 2014

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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