The Overlooked Link: Allen-Masters Syndrome and Endometriosis

How a Little-Known Condition Can Complicate Diagnosis and Treatment for Women in Pain

The Overlooked Link: Allen-Masters Syndrome and Endometriosis

How a Little-Known Condition Can Complicate Diagnosis and Treatment for Women in Pain

What Is Allen-Masters Syndrome?


Allen-Masters Syndrome (AMS) refers to a condition where the ligaments that support the uterus become torn or stretched, often due to trauma or childbirth. The damage causes the uterus to become hypermobile, or “floppy,” which can lead to chronic pelvic pain, abnormal uterine positioning, and a range of gynecological symptoms.

First described in the 1950s by gynecologists Allen and Masters, the syndrome was initially observed in women who experienced difficult or forceful deliveries. However, it's now known that other pelvic trauma—such as surgeries, repeated inflammation, or even invasive endometriosis—can also play a role.

How It Feels: The Symptoms

The symptoms of AMS often overlap with other pelvic disorders, including endometriosis, which makes it incredibly hard to diagnose:


• Chronic pelvic pain, especially on one side
• Pain during intercourse (dyspareunia)
• A feeling of “heaviness” or dragging in the pelvis
• Irregular bleeding or spotting
• Referred pain to the lower back or legs
• Pain made worse by certain movements or positions

These symptoms can persist even after surgery for endometriosis or fibroids, leaving women frustrated and wondering why their treatments didn’t work.

The Complication with Endometriosis

Endometriosis and Allen-Masters Syndrome can coexist—and when they do, they complicate each other.

Endometriosis and Allen-Masters Syndrome can coexist—and when they do, they complicate each other.

Here’s how:

1. Mimicking or Masking Each Other

AMS pain can feel nearly identical to endometriosis. In laparoscopic surgery, torn ligaments or peritoneal defects might be mistaken for endometriosis—or missed entirely.

2. Worsening Each Other

The uterine instability caused by AMS may increase friction and inflammation in the pelvis, potentially exacerbating endometriosis symptoms. Likewise, the invasive nature of endometriosis can weaken uterine ligaments, creating a cycle of worsening pain.

3. Delaying Diagnosis

Because AMS isn’t well known, many surgeons focus only on excising visible endometriosis lesions. If ligament tears or pelvic instability aren’t also addressed, pain may persist despite "successful" surgery.

4. Influencing Fertility

While endometriosis is a known contributor to infertility, AMS can add to the challenge by altering the position of the uterus, interfering with sperm transport, or making embryo implantation more difficult.

Diagnosis: Why It’s Often Missed

AMS is best diagnosed through clinical examination and often requires a high index of suspicion from an experienced gynecologic surgeon. Imaging like MRI or ultrasound may not show ligament damage clearly. In some cases, laparoscopic exploration is the only way to confirm it, by observing a hypermobile uterus or peritoneal defects (like dimples or windows in the pelvic lining).

Unfortunately, many OB/GYNs are not trained to look for Allen-Masters Syndrome, which means it’s often overlooked—especially in patients already diagnosed with endometriosis

What Can Be Done?

If AMS is suspected, the treatment may include:

• Pelvic physical therapy to support surrounding muscles and reduce pain

• Surgical repair or suspension of the damaged ligaments, often during laparoscopy

• Pain management strategies including nerve blocks or hormonal regulation if endometriosis is also present

• Lifestyle modifications to reduce strain on the pelvis (avoiding certain exercises, managing constipation, etc.)

The Takeaway

Allen-Masters Syndrome may not be as well-known as endometriosis, but its impact is very real—especially for women who feel like they've tried everything and still have no answers.

If you’ve had surgery for endometriosis and your pain persists, or if your symptoms don’t quite fit the typical endo profile, it might be worth asking your doctor about Allen-Masters Syndrome.

Women deserve full answers—not partial relief.

Sources & Further Reading

• Howard FM. (2003). Chronic Pelvic Pain. Obstetrics and Gynecology

• Vercellini P et al. (2006). Chronic pelvic pain: pathogenesis and therapy. Best Practice & Research Clinical Obstetrics and Gynaecology

• Tu FF et al. (2017). Beyond Endometriosis: Recognizing and Treating Comorbid Pelvic Pain Disorders. Clinical Obstetrics and Gynecology

What Is Allen-Masters Syndrome?

Allen-Masters Syndrome (AMS) refers to a condition where the ligaments that support the uterus become torn or stretched, often due to trauma or childbirth. The damage causes the uterus to become hypermobile, or “floppy,” which can lead to chronic pelvic pain, abnormal uterine positioning, and a range of gynecological symptoms.

First described in the 1950s by gynecologists Allen and Masters, the syndrome was initially observed in women who experienced difficult or forceful deliveries. However, it's now known that other pelvic trauma—such as surgeries, repeated inflammation, or even invasive endometriosis—can also play a role.

How It Feels: The Symptoms

The symptoms of AMS often overlap with other pelvic disorders, including endometriosis, which makes it incredibly hard to diagnose:


• Chronic pelvic pain, especially on one side
• Pain during intercourse (dyspareunia)
• A feeling of “heaviness” or dragging in the pelvis
• Irregular bleeding or spotting
• Referred pain to the lower back or legs
• Pain made worse by certain movements or positions

These symptoms can persist even after surgery for endometriosis or fibroids, leaving women frustrated and wondering why their treatments didn’t work.

The Complication with Endometriosis

Endometriosis and Allen-Masters Syndrome can coexist—and when they do, they complicate each other.

Endometriosis and Allen-Masters Syndrome can coexist—and when they do, they complicate each other.

Here’s how:

1. Mimicking or Masking Each Other

AMS pain can feel nearly identical to endometriosis. In laparoscopic surgery, torn ligaments or peritoneal defects might be mistaken for endometriosis—or missed entirely.

2. Worsening Each Other

The uterine instability caused by AMS may increase friction and inflammation in the pelvis, potentially exacerbating endometriosis symptoms. Likewise, the invasive nature of endometriosis can weaken uterine ligaments, creating a cycle of worsening pain.

3. Delaying Diagnosis

Because AMS isn’t well known, many surgeons focus only on excising visible endometriosis lesions. If ligament tears or pelvic instability aren’t also addressed, pain may persist despite "successful" surgery.

4. Influencing Fertility

While endometriosis is a known contributor to infertility, AMS can add to the challenge by altering the position of the uterus, interfering with sperm transport, or making embryo implantation more difficult.

Diagnosis: Why It’s Often Missed

AMS is best diagnosed through clinical examination and often requires a high index of suspicion from an experienced gynecologic surgeon. Imaging like MRI or ultrasound may not show ligament damage clearly. In some cases, laparoscopic exploration is the only way to confirm it, by observing a hypermobile uterus or peritoneal defects (like dimples or windows in the pelvic lining).

Unfortunately, many OB/GYNs are not trained to look for Allen-Masters Syndrome, which means it’s often overlooked—especially in patients already diagnosed with endometriosis

What Can Be Done?

If AMS is suspected, the treatment may include:

• Pelvic physical therapy to support surrounding muscles and reduce pain

• Surgical repair or suspension of the damaged ligaments, often during laparoscopy

• Pain management strategies including nerve blocks or hormonal regulation if endometriosis is also present

• Lifestyle modifications to reduce strain on the pelvis (avoiding certain exercises, managing constipation, etc.)

The Takeaway

Allen-Masters Syndrome may not be as well-known as endometriosis, but its impact is very real—especially for women who feel like they've tried everything and still have no answers.

If you’ve had surgery for endometriosis and your pain persists, or if your symptoms don’t quite fit the typical endo profile, it might be worth asking your doctor about Allen-Masters Syndrome.

Women deserve full answers—not partial relief.

Sources & Further Reading

• Howard FM. (2003). Chronic Pelvic Pain. Obstetrics and Gynecology

• Vercellini P et al. (2006). Chronic pelvic pain: pathogenesis and therapy. Best Practice & Research Clinical Obstetrics and Gynaecology

• Tu FF et al. (2017). Beyond Endometriosis: Recognizing and Treating Comorbid Pelvic Pain Disorders. Clinical Obstetrics and Gynecology

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Join Us: Make a Difference Today

Your support can transform lives. Every donation helps us fund research, advocate for better care, and provide essential grants to women facing debilitating conditions.

© Our Daughters Foundation - All Rights Reserved

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Endometriosis, Adenomyosis, and PCOS Autoimmune Conditions

July 17, 20253 min read

The Immune Connection: Are Endometriosis, Adenomyosis, and PCOS Autoimmune Conditions?

By Our Daughters Foundation

More and more women are asking an important question: Could my hormone-related illness also be connected to my immune system?

Conditions like endometriosis, adenomyosis, and polycystic ovary syndrome (PCOS) are often discussed in the context of reproductive health or hormonal imbalance. But researchers are beginning to explore deeper connections—specifically, whether autoimmunity plays a role in these diseases.

Let’s break down what the science says—and what questions remain unanswered.

What Is Autoimmunity?

autoimmunity

The immune system is designed to protect the body from threats like viruses and bacteria. But in autoimmune diseases, the immune system becomes misguided and starts attacking the body’s own cells and tissues.

Common autoimmune conditions include:

• Lupus

• Rheumatoid arthritis

• Hashimoto’s thyroiditis

• Multiple sclerosis

Symptoms vary widely, but many autoimmune conditions involve chronic inflammation, pain, fatigue, and a pattern of flare-ups.

The Immune System and Endometriosis

Endometriosis occurs when tissue similar to the uterine lining grows outside the uterus—causing pain, inflammation, and sometimes infertility. While its exact cause is still debated, many researchers believe that the immune system fails to clear out these rogue cells effectively.

Several studies have found:

• Women with endometriosis often have higher levels of inflammatory markers, like cytokines and prostaglandins.

• Natural killer (NK) cell activity is lower in women with endometriosis, impairing the immune system’s ability to destroy misplaced cells.

• There are elevated autoantibodies in some patients, suggesting an autoimmune component.

Some scientists now consider endometriosis to be a non-classical autoimmune disease—showing many features of one without meeting all diagnostic criteria.

Further reading:

• NIH - Immune dysfunction in endometriosis: https://pubmed.ncbi.nlm.nih.gov/30664929/

• Cleveland Clinic - Endometriosis and the Immune System: https://health.clevelandclinic.org/endometriosis-and-the-immune-system/

What About Adenomyosis?

Adenomyosis is sometimes called the "sister disease" of endometriosis. It occurs when endometrial tissue grows into the muscular wall of the uterus. It's less studied, but immune abnormalities have also been observed.

adenomyosis

Research is still emerging, but here’s what we know:

• Women with adenomyosis show immune cell changes and chronic inflammation within the uterus.

• Some studies report increased macrophage and mast cell activity—cells involved in both immune defense and inflammation

• The condition often coexists with endometriosis, raising questions about shared immune pathways.

While it’s too early to label adenomyosis an autoimmune disorder, it may involve an immune imbalance that contributes to symptoms.

Further reading:

• Frontiers in Immunology - Immunopathogenesis of Adenomyosis: https://www.frontiersin.org/articles/10.3389/fimmu.2021.796273/full

PCOS and Autoimmune Overlap

pcos-and-autoimmune-overlap

Polycystic ovary syndrome (PCOS) is primarily known as a hormonal disorder involving androgen excess and insulin resistance. However, there’s growing interest in its immune connections, especially in women with chronic inflammation or thyroid issues.

Emerging links include:

• Hashimoto’s thyroiditis (an autoimmune thyroid disorder) is more common in women with PCOS.

• Inflammatory markers like C-reactive protein (CRP) are often elevated in PCOS patients.

• Some PCOS patients have anti-ovarian antibodies, suggesting potential autoimmunity.

Still, the autoimmune theory is more speculative in PCOS than in endometriosis.

Further reading:

• Journal of Clinical Endocrinology & Metabolism - PCOS and Autoimmune Disease: https://academic.oup.com/jcem/article/106/9/e3536/6280755

Why Does This Matter?

If immune dysfunction is part of the puzzle, treatment strategies may need to shift. Many women with endometriosis, adenomyosis, or PCOS are treated solely with hormone suppression—but if autoimmunity is involved, we may also need to address inflammation, gut health, and immune regulation.

There’s also hope that newer treatments—like immunomodulatory therapies or even personalized nutrition and lifestyle interventions—could improve outcomes when tailored to the immune system’s role.

Bottom Line

We don’t yet have all the answers, but the research is evolving. Endometriosis, adenomyosis, and PCOS may not be traditional autoimmune diseases—but they often coexist with immune dysfunction, and the overlap deserves attention. At Our Daughters Foundation, we believe in honoring women’s voices, advocating for deeper research, and pursuing whole-body solutions.

If you’ve experienced overlapping conditions like endo, thyroid disease, or unexplained inflammation—you’re not alone.

EndometriosisAdenomyosisPCOSAutoimmune
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