Ovarian Torsion
Obstetrics & Gynecology
Illness script · Obstetrics & Gynecology
Ovarian Torsion
Twisting of the ovary (and often fallopian tube) on its ligamentous supports, compromising blood flow and causing ischemia.
This illness script for Ovarian Torsion covers predisposing factors, classic presentation, mechanism, workup, management, and the clinical pivots that separate it from look-alikes—written for USMLE Step 1 and clerkship reasoning.
01
Predisposing factors
- Peak reproductive age (20s–30s); rare prepubertally but ovarian mass increases risk at any age
- Ovarian mass/cyst >5 cm is the #1 risk factor (stretches suspensory ligament)
- Right side more common (sigmoid limits left-side mobility)
- Ovarian hyperstimulation syndrome (ART/IVF patients)
- Pregnancy (corpus luteum cysts displace ovary)
- Long utero-ovarian ligament in premenarchal girls
02
Presentation
- Sudden-onset severe unilateral lower abdominal/pelvic pain (most common)
- Nausea and vomiting in ~70% (high-yield associated symptom)
- Pain may be colicky or intermittent if incomplete/recurrent torsion
- Low-grade fever and peritoneal signs if necrosis develops
- Adnexal tenderness + palpable adnexal mass on bimanual exam
- No pathognomonic sign — diagnosis is clinical + imaging
03
Pathophysiology
- Ovary rotates on infundibulopelvic and utero-ovarian ligaments
- Venous/lymphatic outflow obstructed first → edema and engorgement
- Arterial inflow eventually compromised → ischemia, necrosis
- Intermittent torsion possible, explaining waxing/waning pain
04
Diagnostics
- Transvaginal ultrasound with Doppler: first-line; absent or reduced ovarian blood flow
- Enlarged, edematous ovary with peripherally displaced follicles ('string of pearls')
- PEARL: normal Doppler flow does NOT exclude torsion (intermittent or partial)
- Urine hCG to rule out ectopic pregnancy immediately
- Definitive diagnosis made intraoperatively (surgical gold standard)
05
Management
- Emergent gynecologic consultation — time-sensitive to preserve ovarian viability
- Diagnostic and therapeutic laparoscopy: detorsion + assess viability
- Ovarian cystectomy/oophoropexy at same operation if mass present
- Oophorectomy only if clearly necrotic (attempt detorsion first even if discolored)
- IV fluids, antiemetics, analgesia while awaiting OR; do NOT delay for serial exams
06
Clinical pivots
How to separate this script from the look-alikes that show up on exams and on the wards.
Ectopic Pregnancy
Positive β-hCG + free fluid/adnexal ring on US; torsion has negative hCG
Ovarian Cyst Rupture
Free fluid in pelvis, sudden pain relief after rupture; ovary is normal size without edema on US
Appendicitis
RLQ pain migrates from periumbilical, anorexia predominates, no adnexal mass; WBC higher; normal ovary on US
Pelvic Inflammatory Disease / Tubo-ovarian Abscess
Bilateral pain, cervical motion tenderness, purulent discharge, fever; gradual onset, sexually active history
Keep reading
Full library- OsteomyelitisInfection of bone, most commonly bacterial, causing bone destruction and marrow inflammation; classified as hematogenous, contiguous, or vascular insufficiency.
- Pelvic Inflammatory DiseaseAscending polymicrobial infection of the upper female genital tract (uterus, tubes, ovaries), most often sexually transmitted.
Educational use only. This illness script is a study framework, not medical advice. Confirm decisions with current guidelines and your clinical supervisors.