The endometrium of the human uterus is the site of embryo implantation and further growth and development. If adhesions occur, the lining will be damaged and the embryo will not be able to implant or grow further, resulting in infertility or miscarriage.
With the increased use of curettage, the incidence of cavity adhesions has increased. As a result, the rate of infertility due to uterine adhesions is also increasing. At present, domestic and international data show that any surgery in the uterus can increase the incidence of uterine adhesions and become one of the common major causes of infertility.
I. Common causes
1. Caused by scraping damage to the uterus. For example, after abortion, midterm induction of labor, full-term delivery, cesarean section, diagnostic scraping and other surgeries.
2, caused by infection. Such as: bacteria, viruses, tuberculosis and other infections.
3, caused by gynecological surgery injury. Such as: after surgery such as myomectomy, cervical surgery, deformed uterus correction, endometrial resection, etc.
4, cauterization, freezing, drug corrosion, radiation therapy of the cervix can cause cervical adhesions atresia.
Second, the mechanism of causing uterine adhesions
1, endometrial repair disorder. There are two mechanisms of endometrial trauma repair: regeneration and repair of endometrium and corresponding small blood vessels; proliferation of fibrous tissue and formation of scar tissue to cover the trauma. If the fibroblast lysozyme activity in the endometrium decreases after endometrial trauma, temporary overproliferation of collagen fibers occurs, while endometrial proliferation is inhibited, resulting in scar formation and adhesions occur.
2, Injury and infection destroy the integrity of the endometrium, resulting in scarring and adhesion healing of the uterine wall tissues, while causing atresia of the uterine cavity, making the uterine cavity smaller or even disappearing.
3.Histological changes of endometrium. The endometrial histology showed secretory phase with 80%, hyperplasia phase with 12%, atrophy phase with 5% and hyperplasia phase with 3%; the scrapings were endometrium with 65%, fibrous tissue with 25%, endocervical lining with 12.5%, endometrial basal layer with 6% and uterine smooth muscle tissue with 4%. Endometrial histological changes are not conducive to egg implantation, placental implantation and embryonic development.
Pathological features
The endocervical adhesions may occur at the endocervix or in the uterine cavity or both. The endocervical adhesions may occasionally have a small amount of intrauterine blood, which is dark red. Endocervical adhesions are defined as filling defects or fibrous tissue at the endocervix on hysteroscopy. Hysteroscopically, connective tissue is seen floating like flocculent in the filling pontine fluid, or connective tissue hardens the uterine cavity like pale scarring distributed in islands between the normal endometrium, and in severe cases the adherent tissue forms bundles of varying thickness. The endometrium commonly has fibrous tissue, smooth muscle, degeneration, mechanized villi tissue and fibrous calcification phenomenon.
Fourth, the classification of uterine adhesions
According to the location of adhesions, they can be classified as complete, partial and marginal; according to the integrity of endometrial cavity and tissue phase, they can be classified as endometrial adhesions, scar connective tissue adhesions and smooth muscle tissue adhesions, and their histological changes are related to clinical symptoms.
V. Grading of uterine adhesions
Hysteroscopy is the most reliable diagnostic method for the diagnosis of uterine adhesions. According to the degree of occlusion of the uterine cavity, especially the adhesions between the opening of the fallopian tubes and the uterine fundus on both sides, it can be divided into three degrees.
1, mild: less than 1/4 of the uterine cavity with dense adhesions and only a few adhesions or no waves at the fundus and the opening of the fallopian tubes.
2. moderate: about 3/4 of the uterine cavity with adhesions, but the uterine wall is not adherent and the fundus, i.e. the bilateral tubal openings, is partially atretic.
3. Severe: thick adhesions in more than 3/4 of the uterine cavity, adhesions in the uterine wall, adhesions in the opening of the fallopian tubes and the uterine fundus.
VI. Clinical manifestations
1. Menstrual irregularities. Amenorrhea accounted for 37%, sporadic menstruation and scanty menstruation accounted for 33%, dysmenorrhea accounted for 2.5%, excessive menstruation accounted for 1%, and normal menstruation accounted for 6%.
2.Primary or secondary infertility accounted for 43%.
3. Post-pregnancy complications: such as recurrent (habitual) miscarriage, placental abruption, premature birth, etc.
4. Combined cervical canal adhesions may cause: retention of menstrual blood, accumulation of blood, fluid or pus in the uterine cavity.
5. Most of the endocervical adhesions are both amenorrhea after abortion surgery.
VII. Diagnosis
1, medical history, symptoms and signs, history of curettage, gynecological surgery, history of gynecological infection, infertility, miscarriage and menstrual disorders.
2.Imaging examination: ultrasound, HSG, etc.
3.Hysteroscopy: It is the most reliable means of diagnosis.
4. Repeated failure of embryo transfer.
VIII. Treatment
1.Uterine adhesion separation surgery: For those who have fertility requirements, hysteroscopic separation surgery is used. After surgery, a birth control ring is placed to prevent re-adhesion and antibiotic treatment is given to prevent infection. Remove the birth control ring 3 months after its insertion and give antibiotic treatment to prevent infection. In severe cases, repeated treatment is needed to achieve results.
2. Stimulate the growth of endometrium: give high-dose estrogen and progestin cycle treatment.
IX. Prevention
1. Gynecological examination or cervical uterine treatment to avoid violent injury or infection.
2.Avoid gynecological infections.
3.Minimize or avoid abortion.
4.Pay attention to menstrual hygiene.
5.Prohibit unclean sexual life.
X. Prognosis
After hysteroscopic separation of uterine adhesions + IUD removal in most patients, after a few cycles of estrogen and progestin replacement therapy, the endometrium of some patients recovers its function and continues pregnancy. If the uterine adhesions are found to continue to exist after IUD removal, treatment can be continued according to the above protocol until the uterine adhesions disappear.