Endometrial fibrosis is a condition involving the formation of scar tissue, also known as intrauterine adhesions, inside the uterus. This scarring can alter the normal structure and function of the uterine lining, the endometrium. The presence of this fibrotic tissue can interfere with regular menstrual cycles and present challenges to fertility. For individuals experiencing symptoms, understanding the nature of this condition is a first step toward seeking appropriate medical evaluation and care.
Understanding the Uterine Lining and Fibrosis
The uterus is lined with a dynamic tissue called the endometrium. This lining is composed of two main layers: a deep basal layer that is always present and a functional layer that responds to monthly hormonal cycles. Hormones cause the functional layer to thicken and develop a rich blood supply in preparation for a potential pregnancy. If pregnancy does not occur, hormonal shifts trigger the shedding of this functional layer, resulting in menstruation, after which the basal layer regenerates a new lining.
Endometrial fibrosis occurs when this regenerative process is disrupted, and functional endometrial tissue is replaced by inelastic, fibrous scar tissue. These scars, or adhesions, are bands of tissue that can bind the walls of the uterus to each other. This scarring can range from a few thin bands to dense adhesions that significantly reduce the volume of the uterine cavity, interfering with the normal thickening and shedding of the uterine lining.
When intrauterine adhesions are extensive enough to cause symptoms, the condition is clinically identified as Asherman’s syndrome. This syndrome represents a more severe manifestation of endometrial fibrosis, where the scarring can partially or even completely obliterate the uterine cavity. This state prevents the endometrium from supporting implantation or undergoing the normal changes of the menstrual cycle. The extent of the scarring directly correlates with the severity of the symptoms.
Causes and Triggers of Scar Formation
The development of endometrial fibrosis is most often initiated by trauma to the basal layer of the endometrium, the foundation from which the uterine lining regenerates. When this deep layer is damaged, the normal healing process can be replaced by the formation of scar tissue, leading to adhesions. The risk of developing this condition is heightened when the uterus has been recently pregnant, as the uterine lining is in a more vulnerable state.
The most common trigger for this uterine injury is a surgical procedure known as dilation and curettage (D&C). A D&C is frequently performed to remove tissue from the uterus after a miscarriage, childbirth, or an elective termination. The instrumentation used can inadvertently scrape too deeply, damaging the basal endometrium and setting the stage for fibrosis. Other uterine surgeries, such as the removal of fibroids (myomectomy) or a cesarean section, can also lead to adhesions.
Beyond surgical trauma, severe inflammation or infection of the uterine lining, a condition known as endometritis, can also provoke scar formation. Infections, such as those associated with pelvic inflammatory disease or genital tuberculosis, can cause significant damage to the endometrium. Another cause is the retention of placental tissue after delivery or a miscarriage. This retained tissue can act as a focal point for inflammation and subsequent scarring.
Recognizing the Signs and Effects
The signs of endometrial fibrosis are related to the amount of functional uterine lining replaced by scar tissue. One of the most common indicators involves changes to the menstrual cycle. Women may notice their periods become significantly lighter (hypomenorrhea) or cease altogether (amenorrhea). This occurs because there is little healthy endometrial tissue left to shed during menstruation.
Some may also experience pelvic pain or severe cramping without substantial blood flow. This can happen if the scar tissue obstructs the exit of what little menstrual blood is produced.
The impact on fertility is a primary concern for many with this condition. The scar tissue creates an altered environment within the uterus, which can prevent a fertilized egg from successfully implanting. The adhesions can cover the surface where implantation would occur or reduce blood flow to the endometrium, depriving a potential embryo of necessary nutrients.
For those who do conceive, endometrial fibrosis can increase the risk of pregnancy complications. The presence of scar tissue can lead to recurrent pregnancy loss, as the embryo may not establish a secure attachment to the uterine wall. Scarring can also affect the development of the placenta, potentially leading to issues like placenta accreta or preterm delivery.
Diagnostic Procedures
Diagnosing endometrial fibrosis often begins when a patient presents with suggestive symptoms, like changes in menstrual patterns or infertility, following a uterine procedure. A healthcare provider will take a detailed medical history, noting any past surgeries like a D&C or infections as risk factors. This history provides clues that point toward the possibility of intrauterine adhesions.
The first imaging step is often a transvaginal ultrasound. While this test can measure the thickness of the endometrial lining, its ability to visualize fine adhesions is limited. A more accurate ultrasound technique is saline infusion sonohysterography (SIS). During an SIS, sterile saline is introduced into the uterine cavity, which separates the uterine walls and allows for a clearer view of any scar tissue.
The definitive method for diagnosing endometrial fibrosis is a hysteroscopy. This procedure involves inserting a hysteroscope—a thin, lighted tube with a camera—through the cervix and directly into the uterus. This allows the physician to see the inside of the uterine cavity in real-time, directly visualizing the extent, location, and severity of any adhesions. Hysteroscopy provides the most accurate assessment for planning treatment.
Management and Therapeutic Strategies
The primary treatment for endometrial fibrosis is a surgical procedure called hysteroscopic adhesiolysis. This minimally invasive surgery is performed using a hysteroscope, the same instrument often used for diagnosis. The surgeon uses specialized micro-instruments, such as tiny scissors or laser fibers, to carefully cut and remove the bands of scar tissue. The objective is to dissect the adhesions and restore the uterine cavity to its normal size and shape.
A challenge after the removal of adhesions is preventing them from reforming during the healing process. Surgeons employ several strategies, including the temporary placement of a physical barrier inside the uterus. This might be a small, inflated balloon catheter or an intrauterine device (IUD), which is left in place for several weeks to keep the walls separated as they heal.
To encourage the regrowth of a healthy endometrium, post-operative hormone therapy is frequently prescribed. This regimen involves a course of estrogen to stimulate the proliferation of the endometrial lining, followed by progesterone to mature the newly grown tissue. The prognosis and chance of successful pregnancy depend on the initial severity of the fibrosis and the quality of the endometrial lining that can be regenerated.