Olha Romanova
chief medical officer, reproductologist, gynecologist, endocrinologist, MD, PhD. ; main specialty: obstetrics and gynecology.

What is endometritis? How does chronic endometritis affect embryo implantation?

What is endometritis?
How does chronic endometritis affect embryo implantation?

Endometritis is an inflammation of the inner lining of the uterine cavity (of endometrium), to which the embryo implants.

What are the symptoms of endometritis?

Acute endometritis is a rather rare emergency condition that usually develops against the background of retention of placental fragments after childbirth or termination of pregnancy or exposure to a pathogen (usually sexually transmitted). In such a situation, a number of symptoms typical of an infection appear (fever, purulent exudation, severe pain in the lower abdomen, general discomfort). In the absence of timely treatment of acute endometritis, infection may spread.

Chronic endometritis is a persistent inflammation of the endometrial mucosa caused by infection of the uterine cavity mainly by bacterial pathogens, usually asymptomatic or having non-specific symptoms, such as abnormal uterine bleeding (“spotting” blood exudation in the middle of the cycle or before / after menstruation), periodic pulling pains in the lower abdomen or exudation with an unpleasant odor.


What is chronic endometritis?

Chronic endometritis is determined in 10% of women of reproductive age, however, this figure is significantly higher in patients with failed embryo implantation – recurrent implantation failure (RIF) and in women with recurrent pregnancy loss – recurrent pregnancy loss (RPL) (10-66%).

Often the consequence of acute and chronic endometritis is the formation of adhesions in the endometrium – synechia, which disrupt the process of implantation and early development of the embryo.

One of the important consequences of endometritis is a lesion, insufficient growth of the endometrium (endometrial hypoplasia) or uneven growth of the endometrium (focal hyperplasia, polyps).

The presence of inflammation in the uterine cavity can disrupt the balance of immune system cells in the endometrium, which can affect the receptivity to the embryo, influence on implantation and proper development of the embryo. (Bashiri et al. 2018).

How can we diagnose chronic endometritis?

Diagnosis of chronic endometritis is carried out using a pipel biopsy of the endometrium or during hysteroscopy.

The diagnosis is confirmed on the basis of histological examination and immunohistochemistry (presence of CD 138) – plasma cells – specific cells of the immune system that respond to inflammation. It is known that the presence of microorganisms that produce inflammation, and the reaction of the immune system that is produced in response, can reduce the receptivity (susceptibility) of the endometrium.

When conducting ultrasound of the pelvic organs, you can often see signs of chronic endometritis in the uneven structure of the endometrium. During hysteroscopy, endometritis often manifests itself in the form of micropolyps, foci of redness and uneven growth.

How to treat chronic endometritis?

It has been established that chronic inflammation of the enometrium causes – a reaction of the immune system and thus affects the possibility of the necessary changes in the endometrium for implantation (impairs the sensitivity of receptors to sex hormones and susceptibility to the embryo). After treatment of chronic endometritis, the prognosis for a successful pregnancy improves.

Treatment of endometritis is carried out with antibacterial drugs for 14 days, with an efficiency of more than 90% of cases after the first course of treatment. Efficacy is monitored three weeks after the completion of the antibiotic by endometrial biopsy.

Considering the importance that chronic endometritis has on the effectiveness of infertility treatment programs, the exclusion of chronic endometritis should be carried out in women with repeated implantation failures, miscarriage, or when receiving data from the anamnesis (inflammatory processes in the past, recurrence of endometrial polyps, impaired placental separation, remnants of placental tissue in the past).