Asherman's Syndrome: Causes, Symptoms, Diagnosis and Treatment — Overview, Diagnosis & Treatment Options | MyMedicPlus

Asherman's syndrome (intrauterine adhesions, IUA, or uterine synechiae) is a condition characterized by the formation of fibrous scar tissue (adhesions) within the uterine cavity or cervical canal, causing partial or complete obliteration of the endometrial lining and the uterine cavity. It is also called traumatic intrauterine amenorrhea or obliterating endometritis. Asherman's syndrome affects an estimated 1-1.5% of women undergoing intrauterine procedures; the reported prevalence rises to approximately 15-40% when hysteroscopy is performed after pregnancy-related D&C for missed abortion. The condition impairs or eliminates menstruation and represents a significant yet underdiagnosed cause of secondary infertility and recurrent miscarriage — accounting for approximately 2-3% of all infertility evaluations and 5-8% of recurrent pregnancy loss investigations. The severity of disease spans a wide clinical spectrum: from minimal thin, filmy adhesions causing minor menstrual irregularity, to complete uterine cavity obliteration causing permanent amenorrhea and absolute infertility. The condition was first described by Joseph Asherman in 1948. Hysteroscopic adhesiolysis followed by post-operative intrauterine stenting and high-dose exogenous estrogen therapy to promote endometrial regeneration is the accepted treatment — but outcomes are limited by the degree of endometrial gland destruction underlying the adhesions, which cannot be fully assessed preoperatively.

Asherman's syndrome results from endometrial injury that disrupts the endometrial basal layer, triggering collagen-producing fibroblast activation and pathological adhesion formation during the healing process, rather than normal endometrial regeneration. Uterine curettage (D&C) accounts for over 90% of all cases — the single most important causative factor. The risk of adhesion formation following D&C is strongly influenced by the reproductive state of the uterus: D&C performed on a recently pregnant uterus (within 1-4 weeks of delivery or abortion, when the basalis layer is most vulnerable) carries substantially higher risk than D&C performed on a non-pregnant uterus — rates of adhesion formation after evacuation of retained products of conception (ERPC) range from 14-40% in prospective hysteroscopic studies. The combination of uterine infection and trauma dramatically amplifies risk — curettage performed on an infected uterus (endometritis, septic abortion) carries approximately 2-3 times higher adhesion formation risk than curettage on a non-infected uterus. Specific high-risk D&C scenarios: postpartum curettage for retained placenta (highest risk — up to 50% adhesion formation rates in some studies), curettage for missed abortion at 9-13 weeks gestation, repeat D&C for incomplete abortion, and aggressive curettage technique. Hysteroscopic surgical procedures: myomectomy (removal of intracavitary or intramural fibroids), hysteroscopic resection of uterine septum, endometrial polyp removal, and intrauterine synechiolysis — adhesion re-formation risk is highest after treatment of extensive synechiae. Uterine tuberculosis: the second most common cause globally (particularly in developing countries) — Mycobacterium tuberculosis genital tract infection causes endometritis with granulomatous destruction of the endometrium, producing dense adhesions not amenable to standard hysteroscopic treatment. Cesarean section scar dehiscence, uterine artery embolization for fibroids, and endometrial ablation are recognized but less common causes.

Asherman's syndrome presents primarily with menstrual abnormalities and reproductive dysfunction. Menstrual irregularities are the hallmark: hypomenorrhea (significantly reduced menstrual flow — most common symptom, present in approximately 75% of women with IUA); amenorrhea (complete absence of menstrual periods) in severe cases with extensive uterine cavity obliteration; cyclical pelvic pain or dysmenorrhea without external menstrual bleeding — this pattern, particularly alarming, indicates hematometra (blood trapped in the uterine cavity by adhesions blocking cervical or lower uterine drainage). Hematometra is diagnosed by ultrasound as a fluid-filled expanded uterine cavity and causes progressively severe cyclical pain mimicking acute abdomen. Reproductive failure: secondary infertility (inability to conceive despite regular unprotected intercourse in a patient who has previously been pregnant) attributable to reduced functional endometrial surface area for embryo implantation; recurrent miscarriage (two or more consecutive pregnancy losses) from impaired embryo implantation, reduced endometrial vascularity, and restricted uterine cavity expansion; repeated IVF implantation failure despite transfer of good-quality embryos; and placenta praevia, placenta accreta, or abnormal placentation in subsequent pregnancies (if conception is achieved) due to disrupted endometrial architecture. Paradoxically, patients with Asherman's syndrome may have apparently normal hormonal cycling (normal FSH, LH, estrogen, and progesterone levels) — the dysfunction is structural rather than hormonal. This distinguishes Asherman's from hypothalamic amenorrhea, POI, and PCOS as a cause of absent periods.

Diagnostic workup begins with clinical suspicion based on history of prior intrauterine procedure combined with new-onset menstrual irregularity or reproductive failure. Saline infusion sonohysterography (SIS): first-line non-invasive investigation — sterile saline is instilled into the uterine cavity via a catheter to provide acoustic contrast; adhesions appear as hyperechoic or hypoechoic linear or bridging filling defects traversing the uterine cavity; sensitivity approximately 75-85% for significant adhesions but may underestimate mild adhesions; also provides an indirect assessment of endometrial thickness and cavity shape. Three-dimensional ultrasound: improves accuracy for adhesion characterization and endometrial volume measurement. Diagnostic hysteroscopy: the gold standard for diagnosis, staging, and immediate treatment of IUA — performed under general anaesthesia, conscious sedation, or local anaesthesia (office hysteroscopy); allows direct visualization of adhesion extent, density, and distribution; identifies the presence of normal-appearing endometrium in areas free of adhesions. Two validated staging systems are used: the American Fertility Society (AFS) 1988 classification (grades I-III based on adhesion extent and menstrual pattern); and the European Society of Gynaecological Endoscopy (ESGE) 2016 classification (Grade I: thin, filmy adhesions easily lysed; Grade II: fibromuscular adhesions with endometrium covering them; Grade III: fibromuscular adhesions with few endometrium remnants; Grade IV: dense fibrous adhesions with absent endometrium requiring vigorous sharp dissection; Grade V: complete obliteration). MRI of the uterus: provides detailed assessment of endometrial thickness, presence of endometrial gland remnants (T2 signal), and myometrial integrity — particularly useful for planning surgery in severe cases and detecting associated conditions (uterine anomaly, fibroids, adenomyosis). Hormonal assessment (FSH, LH, AMH, estradiol) is performed to exclude coexisting ovarian failure as a contributing cause of amenorrhea.

Hysteroscopic adhesiolysis (lysis or cutting of intrauterine adhesions under direct endoscopic visualization) is the definitive treatment for all grades of Asherman's syndrome. Operative hysteroscopy technique: performed under general anaesthesia with a continuous-flow operative hysteroscope; adhesions are divided using sharp scissors (cold scissors preferred for minimal thermal damage to the surrounding endometrium) or 5-French bipolar or monopolar electrodes (for dense or vascular adhesions); the objective is to restore a normal uterine cavity shape, maximum dimensions, and ostial visibility; intraoperative ultrasound guidance is used in complex or severe cases to avoid uterine perforation. Post-operative adhesion prevention and endometrial regeneration: intrauterine device (IUD) or balloon stent (Cook balloon, Foley catheter) placed at the end of hysteroscopy to maintain cavity patency during healing (typically left in situ for 4-8 weeks); high-dose conjugated estrogen or estradiol valerate (4-8 mg/day orally) administered for 4-8 weeks to stimulate endometrial proliferation and regeneration of the basal glandular layer, followed by a progestogen challenge to provoke withdrawal bleed (confirming functional endometrium). Novel regenerative adjuncts under investigation: granulocyte colony-stimulating factor (G-CSF) infusion into the uterine cavity; stem cell therapy (autologous bone marrow-derived stem cells or adipose-derived stem cells) for severe cases with markedly thin endometrium (below 6 mm despite standard therapy) — limited Phase 2 data showing some endometrial thickness restoration. Severe or recurrent Asherman's syndrome: multiple staged hysteroscopic procedures (repeat at 6-8 week intervals) are often required — approaching complete adhesion-free cavity in approximately 60-80% of mild-moderate cases, but fewer than 30% of severe/complete obliteration cases. Surrogate pregnancy (gestational surrogacy): an option for women with persistent severe adhesions where repeated surgery and hormonal treatment has failed to restore adequate endometrium (below 6-7 mm during ovulatory phase with normal vascularity). Expected outcomes post-adhesiolysis: live birth rates approximately 60-70% for mild, 40-50% for moderate, and 20-30% for severe Asherman's syndrome; placental abnormalities (accreta, praevia) risk remains elevated in all post-adhesiolysis pregnancies.

The prognosis for Asherman's syndrome depends critically on the severity of intrauterine adhesions, the extent of underlying endometrial gland destruction, and the number of prior surgical procedures. Mild-to-moderate Asherman's syndrome (ESGE grade I-II) treated with hysteroscopic adhesiolysis achieves cavity restoration in approximately 80-90% of patients; subsequent live birth rates are approximately 60-80%, often approaching those of the general population for mild disease. Moderate-to-severe Asherman's syndrome (ESGE grade III-IV) requires multiple staged surgical procedures in many patients; cavity restoration is achieved in approximately 50-70% after repeat hysteroscopic treatment, with live birth rates of approximately 30-50%. Severe or complete obliteration (ESGE grade V) represents the most challenging prognostic scenario — despite optimal surgical management, live birth rates remain below 25-30%, and persistent thin endometrium (below 6-7 mm on ultrasound) is associated with implantation failure and high miscarriage rates even when the cavity is anatomically restored. Uterine tuberculosis-related Asherman's syndrome carries the worst reproductive prognosis due to irreversible destruction of endometrial glandular elements — pregnancy is often not achievable. Without treatment, amenorrhea and infertility persist, and monthly cyclic pelvic pain from cryptomenorrhea may worsen progressively. Factors predicting better outcomes include younger age at diagnosis, mild adhesion grade on AFS/ESGE scoring, presence of residual endometrium on MRI, adequate endometrial thickness post-surgery, and absence of concurrent uterine infection. Even when natural conception is not achievable, IVF using autologous embryos with a gestational carrier provides an alternative path to parenthood. Placental complications (accreta, praevia) remain elevated in all post-adhesiolysis pregnancies and require specialist obstetric surveillance throughout the pregnancy.

The most important prevention strategy is minimising unnecessary or traumatic intrauterine procedures. When D&C is clinically required after pregnancy complications (missed abortion, postpartum haemorrhage), gentle technique with the lowest effective curettage, combined with prophylactic antibiotics for infected cases, reduces adhesion formation risk. Medical management of early pregnancy failure with misoprostol, when clinically appropriate, avoids surgical uterine trauma. Hysteroscopic management of intrauterine pathology (myomectomy, septum resection) by experienced operators using atraumatic techniques reduces post-surgical adhesion formation. Women undergoing multiple D&C procedures should be counselled about Asherman's risk and monitored with hysteroscopy or SIS if menstrual changes occur. Uterine tuberculosis — a significant cause in endemic regions — requires complete anti-tuberculous therapy to prevent adhesion formation.

Any woman who experiences absent or significantly reduced menstrual flow — particularly following a uterine procedure such as D&C, hysteroscopic surgery, or caesarean section — should be evaluated for Asherman's syndrome. Cyclical pelvic pain without external bleeding (suggesting haematometra) following uterine instrumentation requires prompt evaluation. Women with unexplained infertility or recurrent miscarriage — especially following any prior uterine procedure — should have the uterine cavity assessed with saline infusion sonohysterography or hysteroscopy. Repeated IVF implantation failure, despite good quality embryos, should prompt investigation of the uterine cavity including exclusion of intrauterine adhesions. Early diagnosis and treatment significantly improves fertility outcomes, as long-standing severe adhesions with very thin endometrium are much more difficult to treat successfully.