Asherman syndrome (ORPHA:137686)
A rare, acquired uterine disease characterized by intrauterine adhesions associated with a history of curettage or intrauterine surgery and gynecological symptoms (secondary amenorrhea, hypomenorrhea, pelvic pain, infertility or pregnancy loss).
Epidemiology
The prevalence in the general population is unknown. In infertile populations the prevalence varies from 2.8% to 46% depending on the subpopulation. The greatest risk factor for the disease is iatrogenic trauma to the endometrium.
Clinical description
The severity of intrauterine adhesions (IUA) in Asherman's syndrome can vary between complete obliteration of the cavity to minimal, marginal adhesions. Frequently, the uterine cavity is decreased in size. The adhesions are composed of fibromuscular connective tissue bands, with or without surrounding superficial epithelium or glandular tissue. Adhesions vary markedly in their density and size and can be accompanied by areas of endometrial sclerosis. The gravid uterus appears highly predisposed to adhesions, but IUA may develop in non-gravid uterus following intrauterine trauma. Clinical manifestations include infertility, menstrual irregularities, and recurrent pregnancy losses. Amenorrhea or hypomenorrhea are the most frequent symptoms and may be accompanied by dysmenorrhea during the anticipated menstrual period; some patients continue to have normal periods. When the adhesions are exclusively located in the lower uterine tract and functioning endometrium persists, this syndrome can cause severe pelvic pain and retrograde menstruation. Recurrence of UIA post-surgery is high.
Etiology
The intrauterine adhesions result from uterine trauma including curettage, hysteroscopic myomectomy or endometrial ablation. Adhesions may also be diagnosed in women with genital tuberculosis.
Diagnostic methods
A history of uterine trauma (typically curettage) associated with menstrual abnormalities/inability to conceive are suggestive of Asherman's syndrome. Hysteroscopy provides definitive diagnosis, and can characterize the site and extent of adhesions as well as assess the endometrium. Magnetic resonance imaging (MRI) can be helpful as a supplementary diagnostic tool, especially when the adhesions involve the endocervix. IUAs are visualized as low signal intensity on T2 weighed-image inside the uterus. Transvaginal ultrasound and hysterosalpingography may be used but have lower diagnostic accuracy.
Differential diagnosis
Differential diagnosis on unenhanced ultrasound is normal intrauterine longitudinal folds, on hysterosalpingography or saline infusion ultrasonography it includes polyps and minor fibroids.
Management and treatment
For prevention of intrauterine adherences, a gentle emptying of the uterine cavity after delivery or abortion is mandatory preferably under ultrasound guidance. Intrauterine adhesions are ideally treated with hysteroscopy. Filmy adhesions may be separated by the tip of the hysteroscope. Dense adhesions are treated with hysteroscopic adhesiolysis with either mechanical, electrical or thermal energy techniques. Treatment in severe cases is difficult, and counselling should be offered regarding the lower rate of success and the higher risk of complications. Prevention of re-adhesion is important, and good results have been achieved with intrauterine devices, uterine balloon stent, Foley's catheter, and anti-adhesion barriers. In severe cases, several approaches may be required. Hormonal treatment (oestradiol, combined oestradiol/progesterone) is used to restore the normal endometrium; however, there is no consensus on timing of the administration or the type of regimen. Patients should be assessed one-two months post-operatively as complete resolution of the adhesions is not always possible with a single procedure. Ultrasound, HSG and hysteroscopy are the most common follow-up methods.
Prognosis
Whilst some women achieve pregnancy, the burden of infertility post-treatment is significant. The prognosis is worse for patients with a sclerotic, atrophic endometrium.

                            Last update: 
                            May 2020


                            - Expert reviewer(s): 
                            Dr Eva DREISLER