Understanding Endometrioma

What Is an Endometrioma?

An endometrioma is a benign ovarian cyst associated with endometriosis. It develops when tissue similar to the lining of the uterus grows on or within an ovary, leading to the gradual accumulation of old blood inside the cyst.

Because the fluid inside often appears dark brown, endometriomas are sometimes called “chocolate cysts.” Although they are closely associated with endometriosis, not every person with endometriosis develops an endometrioma.

Endometriomas vary in size and may affect one or both ovaries. Some remain stable for years, while others enlarge over time or contribute to pelvic pain, inflammation, or fertility concerns.

Common Endometrioma Symptoms

Symptoms of an endometrioma vary considerably. Some patients experience significant pelvic pain or menstrual symptoms, while others have no symptoms at all and first learn they have an endometrioma during a fertility evaluation or routine pelvic ultrasound.

Common symptoms may include:

• Pelvic pain
• Painful menstrual periods
• Chronic pelvic discomfort
• Pain during intercourse
• Pain during bowel movements or urination, particularly during menstruation
• Difficulty becoming pregnant
• An ovarian cyst identified during imaging

The severity of symptoms does not necessarily reflect the size of the endometrioma or the extent of endometriosis. Some patients with relatively small cysts experience significant discomfort, while others with larger endometriomas may have few or no symptoms.

What Causes Endometriomas?

Endometriomas develop as a result of endometriosis, a condition in which tissue similar to the lining of the uterus grows outside the uterus. When this tissue involves the ovary, repeated menstrual bleeding and inflammation may gradually lead to the formation of a cyst filled with old blood.

Researchers continue to study the exact causes of endometriosis. Current evidence suggests the condition likely develops through a combination of genetic, hormonal, inflammatory, immune, and environmental factors rather than a single cause.

Not every person with endometriosis develops an endometrioma. Likewise, the presence of an endometrioma does not necessarily indicate severe symptoms, although it does confirm ovarian involvement by endometriosis.

Endometriomas & Fertility

Because endometriomas directly involve the ovaries, they often raise questions about fertility, ovarian reserve, and future family-building plans. While many people with endometriomas conceive naturally, ovarian involvement may influence reproductive health in several ways.

Depending on the individual situation, endometriomas may be associated with:

• Inflammation affecting the reproductive environment
• Reduced ovarian reserve in some patients
• Distortion of normal ovarian anatomy
• Changes that may affect ovarian response during IVF
• Scar tissue involving nearby pelvic structures
• Endometriosis affecting additional reproductive organs

The presence of an endometrioma alone does not determine whether pregnancy is possible. Fertility specialists evaluate ovarian reserve, age, sperm health, fallopian tube function, reproductive history, and the overall extent of endometriosis before making individualized treatment recommendations.

Many patients with endometriomas successfully conceive naturally or through fertility treatment.

How Endometriomas Are Diagnosed

Diagnosis typically begins with a review of symptoms, reproductive history, and pelvic imaging. Because endometriomas often have characteristic features on ultrasound, many can be identified without surgery.

Evaluation may include:

• Medical and menstrual history
• Pelvic examination when appropriate
• Transvaginal ultrasound
• Pelvic MRI in selected situations
• Ovarian reserve testing, including AMH and antral follicle count
• Additional fertility testing when pregnancy is desired

Although imaging can strongly suggest the diagnosis, surgery may occasionally be recommended to confirm the diagnosis, relieve symptoms, or address other concerns. Surgery is not required for every patient with an endometrioma.

Treatment Options for Endometriomas

Treatment depends on several factors, including symptoms, cyst size, patient age, ovarian reserve, fertility goals, and whether pregnancy is currently desired.

Potential management options include:

• Observation with periodic monitoring
• Pain management medications
• Hormonal therapy for symptom control when pregnancy is not being pursued
• Laparoscopic surgery to remove the endometrioma in selected cases
• Fertility treatment when difficulty conceiving is present

When future fertility is important, treatment decisions should carefully balance symptom relief with preservation of healthy ovarian tissue. Surgical removal of an endometrioma may improve symptoms for some patients but can also reduce ovarian reserve because healthy ovarian tissue may be removed along with the cyst.

For this reason, surgery is not automatically recommended simply because an endometrioma is present. Fertility specialists and gynecologic surgeons consider the potential benefits and risks based on each patient’s individual circumstances.

Endometriomas & IVF

Many patients with endometriomas wonder whether surgery should be performed before IVF. The answer depends on several clinical factors, and there is no single recommendation that applies to every patient.

Factors that may influence treatment planning include:

• The size and location of the endometrioma
• Whether one or both ovaries are involved
• Ovarian reserve testing results
• Symptoms such as pelvic pain
• Access to the follicles during egg retrieval
• Previous ovarian surgery
• Overall reproductive goals

Some patients proceed directly to IVF without surgical treatment, while others may benefit from surgery before fertility treatment. Decisions are individualized because surgery may relieve symptoms or improve access to the ovary but also has the potential to reduce ovarian reserve.

During IVF, physicians develop ovarian stimulation protocols based on the patient’s age, ovarian reserve, prior treatment response, and overall reproductive health rather than the presence of an endometrioma alone.

Common Endometrioma Questions

What is an endometrioma?

An endometrioma is a type of ovarian cyst associated with endometriosis. It develops when endometriosis affects an ovary and a cyst containing old blood and endometrial-like tissue forms within or on the ovary.

Because the fluid inside an endometrioma often appears dark brown, it is sometimes referred to as a “chocolate cyst.” Endometriomas may affect one or both ovaries and can vary considerably in size.

Is an endometrioma the same as endometriosis?

An endometrioma is not the same as endometriosis, but the two conditions are directly related. Endometriosis is a chronic condition in which tissue similar to the lining of the uterus grows outside the uterus. An endometrioma develops when endometriosis involves an ovary.

A patient with an endometrioma may also have endometriosis elsewhere in the pelvis, including around the fallopian tubes, uterus, pelvic lining, bladder, bowel, or supporting ligaments. However, the location and extent of endometriosis differ from patient to patient.

What symptoms can an endometrioma cause?

Some endometriomas cause no noticeable symptoms and are discovered during pelvic imaging or fertility testing. Others may be associated with symptoms such as:

• Painful menstrual periods
• Chronic pelvic pain
• Pain during or after intercourse
• Pain during bowel movements or urination, particularly during menstruation
• Abdominal pressure or bloating
• Difficulty becoming pregnant

The intensity of a patient’s symptoms does not necessarily correspond with the size of the endometrioma or the overall extent of endometriosis.

Can an endometrioma cause infertility?

An endometrioma may contribute to fertility challenges, but its presence does not mean pregnancy is impossible. Many patients with endometriomas conceive naturally or with fertility treatment.

Endometriomas may be associated with ovarian inflammation, changes in ovarian anatomy, scar tissue, reduced ovarian reserve, or endometriosis involving other reproductive structures. Fertility may also be influenced by age, egg quality, fallopian tube function, sperm health, reproductive history, and additional medical factors.

A fertility specialist can evaluate the endometrioma as one part of the patient’s complete reproductive health picture.

Does an endometrioma affect ovarian reserve?

Endometriomas may be associated with lower ovarian reserve in some patients, particularly when both ovaries are affected, the cysts are large, or a patient has previously undergone ovarian surgery.

Ovarian reserve may be evaluated using tests such as anti-Müllerian hormone (AMH) and antral follicle count (AFC). These tests provide information about the estimated number of eggs remaining and the expected ovarian response to fertility medications, but they do not directly measure egg quality or determine whether pregnancy is possible.

Because ovarian reserve is also affected by age and individual biology, test results should be interpreted alongside the patient’s medical history, ultrasound findings, prior treatment response, and reproductive goals.

Does an endometrioma affect egg quality?

The relationship between endometriomas and egg quality is complex. Endometriomas may create an inflammatory environment within the ovary and may affect ovarian function, but egg quality is influenced most strongly by age.

An endometrioma does not mean that every egg from the affected ovary will be abnormal or unable to produce a healthy embryo. Fertility specialists generally evaluate age, ovarian reserve, prior IVF outcomes, embryo development, and other clinical factors rather than assuming that an endometrioma alone determines egg quality.

Can you become pregnant naturally with an endometrioma?

Yes. Some patients with endometriomas become pregnant without fertility treatment. The likelihood of natural conception depends on several factors, including age, ovarian reserve, whether ovulation is occurring, fallopian tube function, sperm health, the extent of endometriosis, and how long pregnancy has been attempted.

Patients younger than 35 are generally encouraged to seek a fertility evaluation after 12 months of trying to conceive, while patients 35 or older are generally encouraged to seek evaluation after six months. Earlier evaluation may be appropriate when an endometrioma, known endometriosis, irregular cycles, significant pelvic pain, prior ovarian surgery, or another fertility concern is present.

Does every endometrioma need to be removed?

No. Not every endometrioma requires surgery. Some can be monitored with periodic imaging, particularly when they are not causing significant symptoms, do not have concerning imaging features, and are not interfering with fertility treatment.

Surgery may be considered when an endometrioma causes substantial pain, continues to grow, has unusual imaging characteristics, interferes with access to the ovary during egg retrieval, or presents another clinical concern.

The decision should account for both the possible benefits of surgery and the possibility that removing an ovarian cyst may reduce ovarian reserve by affecting healthy ovarian tissue.

Can surgery for an endometrioma reduce ovarian reserve?

Yes. Surgery involving an ovary may reduce ovarian reserve, particularly when an endometrioma is large, affects both ovaries, has been operated on previously, or is difficult to separate from healthy ovarian tissue.

During surgery, the goal is generally to remove or treat the endometrioma while preserving as much healthy ovarian tissue as possible. However, some loss of follicles or healthy tissue may occur.

Patients who may want children in the future may benefit from discussing ovarian reserve testing, fertility preservation, and the timing of treatment with a reproductive endocrinologist before undergoing ovarian surgery.

Should an endometrioma be removed before IVF?

Not necessarily. Surgery before IVF is not routinely recommended for every patient with an endometrioma. Many patients proceed directly to ovarian stimulation and egg retrieval without first having the cyst removed.

Surgery may be considered when the endometrioma causes significant pain, has concerning features, limits access to follicles during egg retrieval, or creates another medical or technical concern. In other situations, proceeding directly to IVF may help avoid a potential reduction in ovarian reserve associated with ovarian surgery.

The most appropriate sequence depends on the size and location of the endometrioma, whether one or both ovaries are affected, ovarian reserve, age, symptoms, previous surgery, treatment history, and family-building goals.

Can IVF be successful with an endometrioma?

Yes. Many patients with endometriomas successfully undergo IVF. An endometrioma may affect ovarian response or make accessing follicles more technically complex, but it does not automatically prevent eggs from being retrieved, embryos from developing, or pregnancy from occurring.

Fertility specialists consider age, ovarian reserve, the number and location of endometriomas, sperm health, previous treatment response, embryo development, and other reproductive factors when planning IVF treatment.

Can an endometrioma affect egg retrieval?

An endometrioma may sometimes make certain follicles more difficult to reach during an egg retrieval, depending on the cyst’s size and location. Fertility specialists use ultrasound imaging to assess the ovaries and plan a safe approach before the procedure.

Physicians generally try to avoid puncturing an endometrioma during egg retrieval when possible. The presence of a cyst does not necessarily prevent retrieval from the affected ovary or the other ovary.

Should I freeze my eggs if I have an endometrioma?

Egg freezing may be considered when an endometrioma, endometriosis, anticipated ovarian surgery, age, declining ovarian reserve, or future family-building timeline raises concern about reproductive potential. However, egg freezing is not automatically necessary for every patient with an endometrioma.

A fertility specialist can evaluate ovarian reserve, age, whether one or both ovaries are affected, previous surgery, desired family size, and treatment timing to help determine whether fertility preservation may be appropriate.

When ovarian surgery is being considered, discussing fertility preservation before the procedure may be especially important because surgery can sometimes affect ovarian reserve.

Can an endometrioma go away on its own?

Unlike many functional ovarian cysts that develop as part of the menstrual cycle, endometriomas generally do not resolve spontaneously in the same way. Some remain stable in size, while others may grow or cause increasing symptoms over time.

Management may involve observation, medication for symptom control, fertility treatment, or surgery depending on the patient’s symptoms, imaging findings, fertility goals, and overall clinical circumstances.

Can medication eliminate an endometrioma?

Hormonal medications may reduce endometriosis-related pain and suppress disease activity, but they generally do not permanently eliminate an established endometrioma. Symptoms may return after medication is discontinued.

Hormonal suppression also prevents or delays attempts to conceive while it is being used, so it is not considered a fertility treatment for patients actively trying to become pregnant.

Can an endometrioma return after surgery?

Yes. Endometriosis is a chronic condition, and an endometrioma may recur after surgical removal. The likelihood of recurrence varies according to age, disease severity, whether both ovaries are affected, the surgical approach, and treatment following surgery.

Patients who are not immediately trying to conceive may sometimes be offered hormonal treatment after surgery to help manage symptoms or reduce recurrence risk. Recommendations should be individualized based on reproductive plans and medical history.

Is an endometrioma cancerous?

Most endometriomas are benign and are not cancer. However, an ovarian mass should be appropriately evaluated, particularly when it has unusual imaging features, grows rapidly, develops after menopause, or causes new or worsening symptoms.

Additional imaging, blood testing, consultation with a gynecologic specialist, or surgery may be recommended when the diagnosis is uncertain or a cyst has concerning characteristics.

Can an endometrioma rupture?

An endometrioma can rupture, although this is uncommon. Rupture may cause sudden or severe pelvic or abdominal pain and may require urgent medical evaluation.

Sudden intense pain can also be caused by ovarian torsion, bleeding, ectopic pregnancy, or other urgent conditions. Patients experiencing severe pain, dizziness, fainting, fever, vomiting, heavy bleeding, or other concerning symptoms should seek prompt medical attention.

How is an endometrioma monitored?

When observation is recommended, monitoring may include periodic pelvic ultrasound, review of symptoms, and reassessment of the cyst’s size and appearance. Patients pursuing pregnancy may also undergo ovarian reserve testing and a broader fertility evaluation.

The appropriate monitoring schedule depends on the size and appearance of the endometrioma, symptoms, age, fertility plans, and whether any changes are identified over time.

When should I see a fertility specialist about an endometrioma?

Consulting a fertility specialist may be helpful when:

• You are trying to conceive and have been diagnosed with an endometrioma
• You have known or suspected endometriosis
• You have undergone or are considering ovarian surgery
• One or both ovaries are affected
• You have concerns about ovarian reserve
• You are considering egg or embryo freezing
• You have experienced difficulty conceiving or unsuccessful fertility treatment
• You want to understand how treatment may affect future family-building options

A reproductive endocrinologist can evaluate the endometrioma alongside age, ovarian reserve, reproductive anatomy, sperm health, treatment history, and family-building goals to recommend an individualized plan.