Overview
Ovarian Torsion
Topic Overview
Summary
Ovarian torsion is twisting of the ovary on its vascular pedicle, causing venous and then arterial occlusion. It presents with sudden severe unilateral pelvic pain with nausea and vomiting. Risk factors include ovarian cysts/masses and assisted conception. Diagnosis is clinical with ultrasound support; however, normal blood flow on Doppler does NOT exclude torsion. Treatment is urgent surgical detorsion ± cystectomy — time to surgery determines ovarian salvage.
Key Facts
- Peak age: Reproductive age (20-40), but can occur at any age
- Presentation: Sudden severe unilateral pelvic pain + nausea/vomiting
- Risk factors: Ovarian cyst/mass (especially over 5cm), pregnancy, IVF hyperstimulation
- Diagnosis: Clinical suspicion + ultrasound (enlarged ovary, whirlpool sign, absent/reduced flow)
- Treatment: Urgent laparoscopy — detorsion ± cystectomy
- Outcome: Ovarian salvage in 90% if detorsion within 24 hours
Clinical Pearls
Normal Doppler blood flow does NOT exclude torsion — intermittent torsion/detorsion occurs
Right-sided pain is more common and often confused with appendicitis
Nausea and vomiting are universal — their presence supports the diagnosis
Why This Matters Clinically
Ovarian torsion is a gynaecological emergency. Delayed diagnosis leads to ovarian necrosis and loss. It is frequently misdiagnosed as appendicitis, renal colic, or ruptured cyst. High index of suspicion in any woman with sudden-onset unilateral pelvic pain is essential.
Visual Summary
Visual assets to be added:
- Ultrasound showing enlarged ovary with whirlpool sign
- Laparoscopic view of torsed ovary
- Clinical algorithm for acute pelvic pain
- Anatomical diagram of ovarian pedicle
Epidemiology
Incidence
- 5th most common gynaecological emergency
- Accounts for ~3% of acute gynaecological admissions
- Peak in reproductive age (20-40 years)
- Can occur in any age, including paediatrics
Demographics
- Age: Bimodal — reproductive age and post-menopausal
- Side: Right more common than left (may be due to sigmoid colon limiting mobility on left)
Risk Factors
| Factor | Mechanism |
|---|---|
| Ovarian cyst/mass (over 5cm) | Added weight increases torsion risk |
| Ovarian hyperstimulation (IVF) | Enlarged, mobile ovaries |
| Pregnancy | Corpus luteum cyst; relaxed ligaments |
| Previous torsion | Recurrence risk |
| Long utero-ovarian ligament | Increased mobility |
| Dermoid cyst | Heavy; anterior position |
Pathophysiology
Mechanism
- Ovary twists on its pedicle (containing ovarian vessels)
- Venous outflow obstructed first → ovarian congestion
- Arterial inflow obstructed → ischaemia
- If untreated → necrosis and loss of ovary
Intermittent Torsion
- Ovary may twist and partially detorse spontaneously
- Explains variable symptoms and preserved Doppler flow
- Still an emergency — complete torsion can occur suddenly
Timing and Salvage
- Ovarian viability preserved in 90%+ if detorsion within 24 hours
- After 24-48 hours, necrosis risk increases significantly
Clinical Presentation
Symptoms
| Symptom | Frequency |
|---|---|
| Sudden severe unilateral pelvic pain | >0% |
| Nausea and vomiting | 70-80% (almost universal) |
| Colicky or constant pain | Variable |
| Pain radiating to back or thigh | Common |
| Prior episodes (intermittent torsion) | Variable |
Intermittent vs Complete Torsion
Red Flags
| Feature | Significance |
|---|---|
| Sudden-onset severe pain | Vascular event |
| Nausea and vomiting | Almost always present |
| Known ovarian cyst | Increases torsion risk |
| Pregnancy or recent IVF | High-risk population |
| Previous torsion | Recurrence risk |
Intermittent
Episodes of severe pain that resolve spontaneously
Complete
Constant severe pain
Clinical Examination
Vital Signs
- Tachycardia (pain, nausea)
- Usually afebrile (fever suggests necrosis or alternative diagnosis)
Abdominal Examination
- Unilateral lower quadrant tenderness
- Guarding (may mimic appendicitis)
- Palpable adnexal mass (30-50%)
Pelvic Examination
- Unilateral adnexal tenderness
- Adnexal mass
- Cervical motion tenderness (non-specific)
Differential Diagnosis
| Condition | Distinguishing Features |
|---|---|
| Ruptured ovarian cyst | Sudden pain, may have free fluid; less nausea |
| Ectopic pregnancy | Positive pregnancy test; haemoperitoneum |
| Appendicitis | Fever, periumbilical-to-RIF migration, anorexia |
| Renal colic | Haematuria, flank pain, ureterovesicular symptoms |
| PID | Bilateral pain, discharge, fever |
Investigations
Pregnancy Test
- Essential — rule out ectopic pregnancy, identifies pregnancy-related torsion
Ultrasound (Transvaginal Preferred)
| Finding | Sensitivity |
|---|---|
| Enlarged ovary (>cm) | High |
| Absent/reduced Doppler flow | Variable (50-75%) — does NOT exclude torsion |
| Whirlpool sign (twisted pedicle) | Pathognomonic if seen |
| Free fluid | Non-specific |
| Ovarian cyst/mass | Common antecedent |
Blood Tests
- FBC: WCC may be mildly elevated
- CRP: Usually normal or mildly elevated
- Lactate: Not specific
IMPORTANT
- Normal ultrasound does NOT exclude torsion
- If clinical suspicion is high, proceed to diagnostic laparoscopy
Classification & Staging
By Degree of Torsion
- Partial (intermittent detorsion)
- Complete
By Ovarian Status
- Viable (can be salvaged)
- Necrotic (needs oophorectomy)
Management
Immediate
- Analgesia (opioids)
- NPO (in preparation for surgery)
- Urgent gynaecology referral
Definitive Treatment — Urgent Laparoscopy
1. Detorsion:
- Untwist the ovary
- Assess viability (colour change, reperfusion)
- Even dusky-appearing ovaries often recover
2. Cystectomy (if cyst present):
- Remove cyst to reduce recurrence risk
- Preserve ovarian tissue
3. Oophorectomy:
- Only if ovary clearly necrotic and non-viable
- Previously done too frequently — current approach favours detorsion
Oophoropexy
- Suturing ovary to pelvic sidewall to prevent recurrence
- Consider if recurrent torsion or high-risk anatomy
Conservative Management
- NOT recommended — surgical exploration required
- Delay increases risk of ovarian loss
Complications
From Torsion
- Ovarian necrosis and loss
- Infertility (if bilateral or recurrent)
- Peritonitis (if necrotic ovary ruptures)
- Thromboembolic events (rare)
From Surgery
- Standard laparoscopic risks (bleeding, infection, injury)
- Recurrence (10-20%)
Prognosis & Outcomes
Ovarian Salvage
- Over 90% salvage if detorsion within 24 hours
- Decreases significantly after 24-48 hours
- Dark/dusky ovaries often recover after detorsion
Fertility
- Preserved if ovarian salvage achieved
- Recurrence risk: 10-20%
Prognosis by Duration
| Time to Surgery | Ovarian Salvage |
|---|---|
| Under 6 hours | >5% |
| 6-24 hours | 80-90% |
| Over 24 hours | Variable; decreasing |
Evidence & Guidelines
Key Guidelines
- RCOG Green-top Guideline on Management of Adnexal Torsion
- ACOG Practice Bulletin: Adnexal Torsion
Key Evidence
- Detorsion preferred over oophorectomy — even necrotic-appearing ovaries often recover
- Doppler ultrasound has limited sensitivity — clinical judgement paramount
Patient & Family Information
What is Ovarian Torsion?
Ovarian torsion is when the ovary twists on itself, cutting off its blood supply. It causes sudden, severe pain and is an emergency that needs surgery.
Symptoms
- Sudden severe pain on one side of your lower tummy
- Feeling sick or vomiting
- Pain that comes and goes (if the ovary twists and untwists)
Treatment
- Keyhole surgery (laparoscopy) to untwist the ovary
- The ovary can usually be saved if treated quickly
What Happens Next
- Most women recover fully with no impact on fertility
- There is a small risk of it happening again
When to Seek Help
Go to A&E immediately if you have sudden severe pelvic pain, especially if you:
- Feel sick or are vomiting
- Are pregnant or have recently had fertility treatment
- Have a known ovarian cyst
Resources
References
Primary Guidelines
- RCOG. Management of Adnexal Torsion (Green-top Guideline). rcog.org.uk
- ACOG. Practice Bulletin No. 174: Evaluation and Management of Adnexal Masses. Obstet Gynecol. 2016;128(5):e210-e226. PMID: 27776072
Key Studies
- Oelsner G, Shashar D. Adnexal torsion. Clin Obstet Gynecol. 2006;49(3):459-463. PMID: 16885654
- Houry D, Abbott JT. Ovarian torsion: a fifteen-year review. Ann Emerg Med. 2001;38(2):156-159. PMID: 11468611