Endometritis is inflammation of the inner lining of the uterus or endometrium.

Endometritis is different from endometriosis, though both conditions affect the lining of the uterus. Another related condition is endomyometritis, where inflammation happens in the middle layer of the uterus, called the myometrium.

This article provides an overview of endometritis, including its causes, symptoms, diagnosis, and possible complications. We also look at the relationship between endometritis and fertility.

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Endometritis does not always cause symptoms, and some people may be unaware they have it. If symptoms do occur, they can include:

Endometritis is also associated with infertility and pregnancy loss.

Anyone who experiences one or more of these symptoms should contact their doctor to find out the cause.

Endometritis occurs as a result of an infection in the lining of the uterus, known as the endometrium. Such infections may develop due to abnormal bacteria, or bacteria usually found in the vagina.

The cervix is the opening to the uterus, and it usually keeps bacteria out of the uterus. However, bacteria can get in when the cervix is open. This may happen for various reasons, such as during childbirth or surgery.

Possible risk factors for endometritis include:

  • Childbirth or pregnancy loss: These are the most common causes of inflammation of the endometrium.
  • Cesarean delivery: Endometritis is more common after a cesarean section than a vaginal delivery and after an unscheduled versus a scheduled cesarean.
  • Sexually transmitted infections (STIs) and other bacteria: People can pass on STIs, including chlamydia and gonorrhea, during sexual activity. An STI can cause an infection in the endometrium, so it is important to practice safe sex.
  • Bacteria in the uterus: Bacteria normally present in the vagina and cervix can cause endometritis if they enter the uterus.
  • Pelvic procedures: Some procedures can let bacteria into the uterus, especially those that involve accessing internal organs and tissues via the cervix or uterus. Examples include:
    • dilation and curettage, which involves removing tissue from the inside of the uterus
    • endometrial biopsy, which involves taking a tissue sample of the endometrium
    • hysteroscopy, which is when a doctor inserts a small telescope into the uterus to look for abnormalities
    • intrauterine device insertion
    • cesarean section
  • Pelvic inflammatory disease (PID): PID is an infection in the pelvis that is often associated with endometritis. Without swift medical treatment, PID can become serious.

Endometritis is different from endometriosis, though both conditions affect the lining of the uterus.

Endometritis is when the lining of the uterus becomes inflamed due to an infection. Endometriosis is where tissue similar to the lining of the uterus grows outside the uterus. An infection does not cause endometriosis.

The symptoms of endometriosis vary from one person to another but typically include:

There is currently no cure for endometriosis, though treatments are available to help alleviate the symptoms.

Polycystic ovarian syndrome (PCOS) is a condition that affects how a person’s ovaries function. The condition relates to hormonal imbalances in the body. Unlike endometritis, PCOS does not occur due to infection.

Experts do not know the exact cause of PCOS. However, the condition likely has a genetic link since it often runs in families.

In order to receive a diagnosis of PCOS, a person must experience two or more of the following:

  • Irregular periods: This indicates that the ovaries are not regularly releasing eggs.
  • Excess androgens: Androgens are male sex hormones. Both males and females have androgens, but some people with PCOS have higher levels than usual. Excess androgens can lead to physical changes, such as excessive facial or body hair.
  • Polycystic ovaries: The ovaries can become enlarged, and ultrasound shows the presence of multiple small follicles or fluid-filled cysts in the ovaries.

PCOS is difficult to diagnose because its symptoms mirror those of other conditions, such as:

There is currently no cure for PCOS, though treatments are available to help alleviate the symptoms.

Endometritis can affect a person’s ability to get pregnant or stay pregnant. Inflammation of the uterus can cause scarring, which prevents an embryo from implanting and developing normally within the uterine wall.

A 2016 review reports that chronic endometritis can affect fertility by stopping the fertilized egg from implanting into the uterus lining and increasing the likelihood of repeated pregnancy loss.

However, the same study reports that antibiotic treatment can lead to a significant improvement in fertility and successful pregnancies.

A study from 2018 worked with 95 females who had fertility issues. They found that over half of the participants had chronic endometritis and that antibiotic therapy improved their symptoms by more than 80%. With successful treatment, they had increased pregnancy and childbirth rates.

Fertility specialists sometimes suggest that people receive testing or treatment for endometritis, especially in cases of repeated pregnancy loss or multiple unsuccessful in vitro fertilization cycles involving embryos of good quality.

When diagnosing endometritis, a doctor will start by taking a medical history and performing a physical exam. The latter will likely involve a pelvic exam to evaluate the internal reproductive organs. The doctor will look for tenderness in the uterus and possible discharge from the cervix.

A doctor may carry out the following tests to rule out other possible causes of the symptoms:

  • Blood testing: A complete blood count can help identify signs of infection or inflammation.
  • Cervical cultures: The doctor may take a swab from the cervix to look for chlamydia, gonorrhea, or other bacteria.
  • Wet mount: The doctor may collect discharge from the cervix and analyze it under a microscope. This can help to identify other causes of infection or inflammation.
  • Endometrial biopsy: This procedure involves dilating the cervix to allow a small instrument or pipelle into the uterus. The instrument takes a small sample of tissue, and a doctor sends the sample off to the lab for analysis. It is a brief procedure that can take place in a doctor’s office.
  • Laparoscopy or hysteroscopy: These procedures involve the use of a scope, which is a tiny camera attached to a thin, flexible tube. This allows a doctor to look directly inside the uterus.

A person should contact a doctor anytime they experience pelvic pain or discomfort or unusual discharge or bleeding. Some pelvic infections can cause serious complications, so it is important to start treatment quickly.

Treatment for endometritis aims to eliminate the infection and resolve inflammation of the uterus. Treatment will also prevent any further complications. This may involve the following:

  • Antibiotics: These medications fight the bacteria causing inflammation of the uterine lining. If the infection is very severe, a person may require intravenous antibiotics in the hospital.
  • Treating sexual partners: If the endometritis is due to an STI, the person’s sexual partner or partners may also require antibiotic treatment.
  • Further tests: A person may require cervical cultures or an endometrial biopsy to ensure that the infection is completely gone after finishing the course of antibiotics. If the infection remains, a doctor may recommend a different antibiotic.
  • Surgery to remove tissue: A surgeon may need to remove any tissue left inside the uterus following childbirth or pregnancy loss.
  • Treating any abscesses: In some cases, the infection may cause an abscess within the abdomen. A person may then require surgery or a needle aspiration to remove infected fluid or pus from the abscess.

People who are at risk of developing endometritis should receive information from their doctor or nurse about the signs and symptoms to look out for. This includes people who have recently given birth and those who have recently undergone a pelvic examination or procedure.

A doctor may prescribe antibiotics to help prevent endometritis in situations where a person is at risk of developing the condition, such as when undergoing a scheduled pelvic procedure or surgery. A doctor may prescribe the antibiotics prior to or immediately following the procedure.

Because STIs can also cause endometritis, it is crucial that people maintain their sexual health, especially with nonmonogamous partners. Behaviors that can help include attending regular screenings for STIs and consistently using barrier contraception, such as condoms.

Without treatment, endometritis may cause the following complications:

  • infertility
  • pelvic peritonitis, which is a general pelvic infection
  • abscess in the pelvis or uterus
  • septicemia, which is bacteria in the bloodstream
  • septic shock, which is severe and potentially life threatening low blood pressure due to septicemia

The outlook for a person with endometritis is very good, especially if they receive antibiotic treatment.

Getting a prompt diagnosis and appropriate treatment significantly reduces the risk of complications.