A 28-year-old married woman from Delhi presents with primary infertility of 3 years duration. She reports regular menstrual cycles (28–30 days) with normal flow and no dysmenorrhea. Her husband's semen analysis is normal. On examination, she is of normal build (BMI 22 kg/m²), with no hirsutism or acne. Pelvic examination reveals a fixed, retroverted uterus with restricted mobility. Transvaginal ultrasound shows a normal endometrial thickness, patent fallopian tubes on hysterosalpingography, and multiple small cysts in both ovaries. What is the most likely diagnosis?

Explanation

## Clinical Diagnosis: Endometriosis ### Key Clinical Features **Key Point:** The combination of primary infertility, regular ovulatory cycles, normal semen analysis, and a **fixed, retroverted uterus with restricted mobility** on pelvic examination is highly suggestive of endometriosis. ### Why Endometriosis? 1. **Fixed uterus** — ectopic endometrial tissue causes adhesions and fibrosis, restricting uterine mobility 2. **Normal ovulation** — endometriosis does not prevent ovulation; it causes infertility through: - Pelvic adhesions (mechanical obstruction) - Altered peritoneal fluid (toxic to sperm and embryo) - Impaired implantation (altered endometrial receptivity) 3. **Normal HSG** — patent tubes rule out tubal obstruction, though endometriosis can cause subtle tubal dysfunction 4. **Normal ovarian morphology** — the "multiple small cysts" are likely corpus luteum or follicles, not PCOS-pattern polycystic ovaries ### Diagnostic Confirmation - **Gold standard:** Diagnostic laparoscopy with histological confirmation - **Imaging:** Transvaginal ultrasound may show endometriomas (chocolate cysts), but absence does not exclude disease - **Clinical examination:** Fixed uterus and adnexal nodularity are classic signs ### Pathophysiology of Infertility in Endometriosis | Mechanism | Effect | | --- | --- | | Pelvic adhesions | Mechanical distortion of tubes and ovaries | | Peritoneal inflammation | Increased prostaglandins, altered cytokines | | Impaired ovulation | Luteinized unruptured follicle (LUF) syndrome | | Endometrial dysfunction | Reduced integrin expression, impaired implantation | | Sperm dysfunction | Phagocytosis by activated macrophages | **High-Yield:** Endometriosis is present in 20–50% of infertile women and is a leading cause of secondary infertility, but can present with primary infertility if disease is severe. **Clinical Pearl:** The absence of dysmenorrhea does NOT exclude endometriosis; up to 20% of women with endometriosis are asymptomatic. [cite:Berek's Gynecology 16e Ch 12]