A 28-year-old woman with secondary infertility presents with a history of recurrent pregnancy loss and thrombotic episodes. Hysterosalpingography shows a filling defect in the uterine cavity. Which finding best distinguishes Asherman syndrome from uterine septum as the cause of her infertility and recurrent miscarriage?

Explanation

## Asherman Syndrome vs. Uterine Septum: Discriminating Features ### Key Discriminating Feature **Key Point:** Asherman syndrome is characterized by intrauterine adhesions (synechiae) with reduced endometrial thickness, whereas a uterine septum is a congenital Müllerian anomaly with a normal, intact endometrium. These are fundamentally different pathologies requiring different management. ### Comparative Table | Feature | Asherman Syndrome | Uterine Septum | | --- | --- | --- | | **Pathology** | Acquired adhesions (synechiae) | Congenital Müllerian anomaly | | **Endometrial thickness** | Reduced/atrophic | Normal | | **Hysteroscopic appearance** | Adhesions, scarring, reduced cavity | Septate cavity, normal endometrium | | **3D ultrasound** | Cavity distorted by adhesions | Septate uterus, normal wall thickness | | **Etiology** | D&C, infection, curettage, TB | Incomplete Müllerian fusion | | **Reversibility** | Potentially reversible with lysis | Requires surgical metroplasty | | **Miscarriage mechanism** | Poor endometrial receptivity | Inadequate vascularization of septum | | **Prevalence in infertility** | 1–2% of infertile women | 3–4% of infertile women | ### Clinical Pearls **Clinical Pearl:** Asherman syndrome results from destruction of the basalis layer of endometrium, leading to permanent loss of endometrial tissue and adhesion formation. Common causes include aggressive D&C (especially post-abortion or post-miscarriage), intrauterine infection (TB, schistosomiasis), and uterine artery embolization. **Clinical Pearl:** A uterine septum is the most common congenital Müllerian anomaly and is associated with recurrent miscarriage due to poor vascularization of the septum (not adhesions). The endometrium is normal but the septum itself is avascular. **High-Yield:** Hysteroscopy is diagnostic for Asherman syndrome (direct visualization of adhesions and scarring). 3D ultrasound or MRI is superior for diagnosing uterine septum (shows the septate cavity with normal wall thickness and normal endometrium). **Mnemonic: ASHERMAN** — **A**dhesions, **S**carring, **H**istory of curettage, **E**ndometrial atrophy, **R**educed cavity, **M**anagement by lysis, **A**cquired condition, **N**ot congenital. ### Why Intrauterine Adhesions Distinguish 1. **Asherman syndrome** = adhesions + reduced endometrial thickness (acquired) 2. **Uterine septum** = normal endometrium + septate cavity (congenital) 3. Adhesions are pathognomonic for Asherman; a septum is pathognomonic for Müllerian anomaly 4. Management differs: Asherman requires hysteroscopic lysis; septum requires metroplasty