Inflammation of the uterus: Causes and Impact on Fertility

The Latin term for the inflammation of the uterus is endometritis.

Endometritis is an inflammatory disease of the lining of the uterus caused by infection. 

The uterus is a hollow organ, located between the rectum and the bladder in the small pelvis of women. It consists of the body and the cervix. 

The uterus is the most important organ of the female reproductive system, essential in pregnancy for the growth and development of the fetus. 

The wall of the uterus consists of three layers:

Peritoneum – a thin layer of tissue surrounding the uterus that protects the surface of the uterus.

Myometrium – the middle muscle layer. During pregnancy, it expands. After birth, it returns to its original size during the 6th-8th week.

Endometrium - the inner layer formed by the lining of the uterus. The endometrium is made up of two layers, the outer and inner. The outer is renewed every month after menstruation, and the inner layer, which does not change and remains the same, unchanged. 

Inflammation of the uterus means inflammation of one of its parts.

Depending on the location where the infection takes place, it can be an inflammation inside the uterus, throat or cervix, which is most commonly caused by bacteria: staphylococci, streptococci, enterococci, or sexually transmitted diseases.

Inflammation of the uterus often occurs in women after miscarriage, childbirth, but also for other reasons. 

Categorisation of uterine inflammation by layers

Inflammation of the inner lining of the uterus may occur, which most often arises when an infection from the cervix or vagina of the uterus, or arises from dead tissue left behind after scrapings, or sporadically by blood-borne transmission. 

If the inflammation spreads further from the mucosa, inflammation of the musculature of the body of the uterus occurs, and this progression occurs most often after an abortion and can even cause peritonitis, i.e. inflammation of the lining of the inner wall of the abdomen.

Inflammation of the uterus is one of the causes of infertility, or fetal prematurity and miscarriage. 

Endometritis can affect all layers of the endometrium of the uterus.

Decidua refers to the lining of the uterus at the end of the secretory phase of the menstrual cycle and in pregnancy. The infection of the decidua is called deciduitis.

As long as the woman has sufficient immunity, usually the infected decidua will slough off on its own within a few days. A foul-smelling vaginal discharge clearly speaks of an infection in the uterus. 

An infection that affects the muscles of the uterus is called myometritis. 

Inflammation of the uterus can take place as an acute or chronic form

Acute inflammation is a short-term form of inflammation that is transient and often occurs after miscarriages and fetal remains left in the uterus, after childbirth, in pelvic inflammatory diseases, or infections of bacterial or viral origin. 

Chronic inflammation most often appears after the acute stage, but it can proceed in a weaker form, even without the initial acute inflammation. If it progresses to a chronic form, it can threaten a woman's fertility. 

The inflammation of the uterus can have various causes.

It most commonly occurs after miscarriage or childbirth. 

Inflammation can occur directly in the uterus, or it can be transferred to the uterus from the surrounding area. 

Infection occurs when bacteria normally found in the vagina or on the cervix are transferred to the inside of the uterus and cause inflammation there. For example, when the cervix is open, during menstruation, after miscarriages, childbirth or intrauterine procedures. 

Another possible cause of infection is surgery performed during caesarean section or uterine surgery, when the uterine tissue is disrupted by the incision. 

Transmission via the blood route and from the top down is very rare, for example in respiratory tract infections or tuberculosis. 

The most common causative agents of common infection are streptococci, staphylococci, enterococci, echerichia coli , but also chlamydia trachomatis, mycoplasma, and other bacteria. 

Inflammation related to childbirth or miscarriage 

Most cases of uterine inflammation are related to childbirth. It is the most common postpartum infection. 

After spontaneous delivery, the incidence is 1-2%.

Some factors can increase this risk to 5-6% after vaginal delivery.

The uterus is sterile. It becomes non-sterile only after the amniotic sac ruptures during labour. This is how bacteria can move into the inner part of the uterus, or also during a caesarean section when the uterine tissue is disrupted. 

The condition can develop when the cervix is open after childbirth or surgery, when bacteria get into the uterus. 

Uterine infection is up to a 25-fold greater after a caesarean section.

Risk factors:  

• Infection of the amniotic sacs or amniotic fluid. 
• Low hygiene habits.
• Prolonged labor.
• Multiple cervical examinations.
• Young age of the mother.
• Obesity
• Amniotic fluid stained with meconium, the first stool of the fetus.
• Colonization of the vagina by bacteria such as streptococci, chlamydia trachomatis and others.

Inflammation unrelated to miscarriage and childbirth 

In women who have never goven birth, the causes include an early onset of sexual activities, multiple sexual partners, poor hygiene habits, promiscuity. 

Sexually transmitted infections, chlamydia, gonorrhoea, or bacteria can be the causative agent of uterine inflammation.   

It can also occur during surgical procedures such as uterine tissue sampling for biopsy, cervical dilation, or curettage. 

After investigations such as hysteroscopy, where a probe with a camera is inserted into the uterus to look for abnormalities. 

It can occur after insertion of a pessary or an intrauterine device (IUD), but the risk is very low at 0.1%. 

Being treated by a person who is not  a professional helathacre worker. In the past, they were common after illegal abortions that caused a great number of deaths in women. 

Symptoms may vary.

The intensity and occurrence of symptoms are individual for each woman, which depends on which layer of the uterus the inflammation is located in, what bacteria caused the infection, and also on the body's defences.

Women with weakened immunity or after exhausting childbirth or miscarriage may tolerate infection and inflammation of the uterus worse and so the clinical manifestations are more intense. 

Symptoms of uterine inflammation

• The typical and initial symptoms begin with an elevated temperature, a fever with chills.
• Sensations of tension in the lower abdomen, followed by severe pain. 
• Pain in the lower abdomen, pelvis or around the rectum.
• Vaginal bleeding occurring outside the menstrual cycle.
• Unusual vaginal discharge, which is characteristic according to the causative agent of the infection. At first, the discharge tends to be watery, with the presence of pus, up to with an admixture of blood. In gonorrhoeal infection, the discharge is fishy smelling.
• Fatigue, nausea, which is related to the disease.
• Constipation, flatulence during defecation, there may be a feeling of discomfort when defecating, up to pain in the small pelvis.

In the initial acute stage, dysmenorrhea, severe painful menstruation, occurs. 

In the transition to the chronic form, on the contrary, the person may experience very mild period or amenorrhoea, i.e. complete absence of a period, even total sterility. 

Symptoms after childbirth: 

• Temperature rise to 39 - 40° C.
• Accelerated pulse 100 - 140/minute.
• Lack of appetite
• Weight loss
• Blood test shows slightly elevated leukocytes
• Pain in the area below the stomach.
• Smelly and purulent lochia (vaginal discharge after giving birth), vaginal discharge in the postpartum period. 

Symptoms of the chronic form:

The chronic form is often asymptomatic, or there are only minimal symptoms.

• Abnormal uterine bleeding.
• Dysmenorrhoea – painful menstrual period with cramps.
• Dyspareunia – painful intercourse.
• Smelly purulent discharge with frequent urination, similar to cystitis.
• From a slightly elevated temperature to fever.

At the appearance of the first symptoms, every person should visit their gynaecologist, because early and rapid diagnosis is important, especially for women who are planning a pregnancy. 

The doctor must distinguish inflammation of the uterus from inflammation of the urinary tract, ovaries, fallopian tubes, or inflammation of the surrounding tissues. 

To determine the diagnosis, the person undergoes a few examinations. 

During a gynecological (pelvic) examination with palpation, the doctor examines the pelvis, notices a softer uterus, which is painful to the touch. Pain may appear throughout the entire small pelvic area. The gynecologist checks for uterine spasming and vaginal discharge. 

A blood sample will be taken to be tested, which will point to elevated inflammatory parameters.

Also, a vaginal swab for culture, to check for chlamydia, gonorrhea and other bacteria.

Sonography, transvaginal sonography - during the examination, a change in the mucous membrane of the mastitis, signs of hemorrhage and increased thickness of the mucosa are visible. 

An endometrial biopsy in which a small amount of the lining of the uterus is taken for examination. 

Laparoscopy, a hysteroscopy that allows you to look directly at the uterus. 

During hysteroscopy, bright red spots with white dots are visible on the lining of the uterus, or small white spots that bleed easily are visible. Swelling and the appearance of micropolyps are visible. 

During a weak infection of the lining of the uterus, the inflammation during menstruation peters off and the uterus heals spontaneously. When it penetrates into the deeper layers of the uterus, endomyometritis develops, which also affects the uterine musculature.

Untreated inflammation can spread further into the cervix; with inflammation of the upper tissue surrounding the uterus, the inflammation can spread to the fallopian tubes. 

Untreated infection leads to reproductive complications and fertility problems.