Chronic Endometritis, Pregnancy, and Fibroids: What to Know

If you are trying to conceive or navigating recurrent miscarriage, you may see the terms chronic endometritis (CE) and uterine fibroids come up in evaluations. Both conditions affect the uterus, can share symptoms like abnormal bleeding, and may influence fertility and pregnancy outcomes. Here’s a clear, evidence-informed guide to how they relate, how they’re diagnosed and treated, and what steps to take if you’re planning a pregnancy.

What is chronic endometritis?

Chronic endometritis is persistent, low-grade inflammation of the uterine lining (endometrium). Unlike acute endometritis—which typically follows childbirth, miscarriage, or a pelvic infection and causes fever and significant pain—chronic endometritis often produces subtle or no symptoms. It’s commonly linked to a polymicrobial, low-level infection or biofilm and may follow uterine instrumentation (such as dilation and curettage), retained tissue after miscarriage or delivery, or sexually transmitted infections. In many women, no single cause is identified.

Trusted overviews from the National Institutes of Health’s NCBI Bookshelf describe endometritis as inflammation of the endometrium with acute and chronic forms and outline risk factors such as postpartum or post-procedure states and pelvic infections (NIH/NCBI Bookshelf, StatPearls: Endometritis).

Symptoms and who is at risk

Many people with chronic endometritis feel well. When symptoms occur, they may include:

• Abnormal uterine bleeding (spotting between periods, prolonged or heavy periods)
• Mild pelvic discomfort or lower abdominal pain
• Unusual vaginal discharge
• Pain with intercourse

Risk may be higher after pregnancy loss or delivery, after uterine procedures, with retained intrauterine tissue, or in the setting of untreated sexually transmitted infections. The U.S. Centers for Disease Control and Prevention (CDC) notes that sexually transmitted infections and pelvic inflammatory disease can involve the upper reproductive tract, including the endometrium (CDC: PID Treatment Guidelines).

How chronic endometritis can affect fertility and pregnancy

Chronic inflammation can disrupt the endometrium’s receptivity to an embryo, potentially contributing to infertility, recurrent implantation failure (especially in IVF), or recurrent pregnancy loss in some patients. Observational studies have found that treating CE is associated with improved implantation and live birth rates in certain infertility populations. While research is ongoing, many fertility specialists screen for CE in the workup of recurrent implantation failure or unexplained recurrent miscarriage.

In pregnancy, poorly controlled or unrecognized chronic inflammation is theoretically linked to complications such as miscarriage or preterm birth; however, high-quality data remain limited. The key insight: if CE is suspected, diagnosing and treating it before conception or embryo transfer is prudent.

Diagnosis: getting a clear answer

Because symptoms are often nonspecific, diagnosis relies on targeted testing:

• Endometrial biopsy: A thin catheter samples the lining in the office. Pathology identifies plasma cells—the hallmark of chronic inflammation—often highlighted by a CD138 stain. This is considered a gold-standard diagnostic approach in reproductive medicine.
• Hysteroscopy: A tiny camera visualizes the uterine cavity. Findings suggestive of CE include micropolyps, focal redness (hyperemia), and stromal edema. Hysteroscopy can be combined with biopsy and treatment of other issues, such as removal of a small polyp.
• Microbiology: Some clinicians add cultures or molecular testing to identify organisms, especially if symptoms persist after empiric therapy.

Evaluation for coexisting uterine conditions—such as polyps, adhesions, or fibroids that distort the uterine cavity—is also important because these can independently affect fertility and bleeding.

Treatment: what to expect and timeline

Most CE is treated with antibiotics directed at likely bacteria. A commonly used empiric regimen in reproductive medicine involves a course of doxycycline; clinicians may tailor therapy or add coverage based on local patterns, biopsy results, or persistent symptoms. If an STI is identified, CDC-recommended regimens and partner management apply (CDC: STI Treatment Guidelines).

Many specialists repeat an endometrial biopsy or perform hysteroscopy after treatment to confirm resolution before proceeding with fertility treatments. If CE persists, a second course of antibiotics or alternative regimens may be used. When retained tissue, a polyp, or a cavity-distorting fibroid is present, surgical management may be needed to restore a healthy uterine environment.

Authoritative summaries on endometritis management and distinctions between acute and chronic forms are available via the NIH’s NCBI Bookshelf (StatPearls) (NIH/NCBI Bookshelf: Endometritis).

Where fibroids fit in

Uterine fibroids (leiomyomas) are noncancerous growths of the uterine muscle. They are very common and often asymptomatic. Whether fibroids affect fertility depends on their size and location:

• Submucosal fibroids (bulging into the uterine cavity) and some intramural fibroids that distort the cavity are associated with reduced fertility, higher miscarriage rates, or pregnancy complications.
• Subserosal fibroids (on the outside of the uterus) rarely affect fertility.

Trusted resources such as MedlinePlus (NIH) and the American College of Obstetricians and Gynecologists (ACOG) offer accessible overviews of symptoms, diagnosis, and treatment options (MedlinePlus: Uterine Fibroids; ACOG: Uterine Fibroids FAQ).

Do fibroids cause chronic endometritis? Research is evolving. Some studies suggest CE may be more common in women with submucosal fibroids—possibly due to mechanical irritation or changes in the local uterine environment—but definitive cause-and-effect data are limited. What’s clear is that both conditions can coexist and compound fertility challenges if the uterine cavity is distorted or the lining is inflamed.

Planning for pregnancy: a practical pathway

• Get a uterine cavity assessment: A saline infusion sonogram, hysterosalpingogram, or hysteroscopy can identify cavity-distorting fibroids, polyps, or adhesions.
• Ask about CE screening: If you have recurrent implantation failure, recurrent miscarriage, or unexplained abnormal bleeding, discuss endometrial biopsy (with CD138 staining) or hysteroscopy.
• Treat what is found—first: Clear CE with antibiotics and address cavity-distorting fibroids (myomectomy or hysteroscopic resection when appropriate) before trying to conceive or proceeding with embryo transfer.
• Optimize overall health: Screen and treat STIs per CDC guidance, manage iron deficiency if heavy bleeding is present, and maintain a healthy weight and balanced nutrition to support fertility.
• Coordinate timing: After myomectomy, your clinician will advise when it’s safe to try for pregnancy. A repeat biopsy or imaging may be recommended to confirm a receptive uterine lining.

When to seek care

Contact a gynecologist or reproductive endocrinologist if you have:

• More than 6–12 months of infertility (earlier if over 35)
• Recurrent implantation failure or two or more pregnancy losses
• Abnormal uterine bleeding, pelvic pain, or unusual discharge
• Known fibroids with difficulty conceiving or miscarriages

Early diagnosis and a targeted plan can meaningfully improve outcomes.

Bottom line

Chronic endometritis and fibroids sometimes travel together and can each affect fertility and pregnancy. The good news: both are diagnosable and, in many cases, treatable. A stepwise approach—evaluate the uterine cavity, test for and treat CE, and address cavity-distorting fibroids—can restore a healthier environment for implantation and pregnancy.

Sources and further reading

• NIH/NCBI Bookshelf (StatPearls): Endometritis overview – https://www.ncbi.nlm.nih.gov/books/
• CDC: Pelvic Inflammatory Disease (PID) Treatment Guidelines – https://www.cdc.gov/std/treatment-guidelines/pid.htm
• CDC: STI Treatment Guidelines – https://www.cdc.gov/std/treatment-guidelines/default.htm
• NIH MedlinePlus: Uterine Fibroids – https://medlineplus.gov/uterinefibroids.html
• ACOG: Uterine Fibroids FAQ – https://www.acog.org/womens-health/faqs/uterine-fibroids

This article is for educational purposes and does not replace personalized medical advice. Always consult your clinician for diagnosis and treatment options tailored to you.