Ovarian torsion is the twisting of an ovary around the adnexal ligaments. It most commonly occurs in women of childbearing age. Risk factors include ovarian enlargement (e.g., ovarian cysts, tumors, or hyperstimulation syndrome), laxity of pelvic ligaments, a history of pelvic inflammatory disease, and previous pelvic surgery. Torsion can lead to venous congestion and edema, which cuts off the blood supply to the ovary. Patients present with sudden onset unilateral lower abdominal or pelvic pain, and there may be a palpable adnexal mass and adnexal tenderness. In partial ovarian torsion, the pain may be intermittent or resolve spontaneously. Diagnosis is made using pelvic ultrasound. Torsion is a surgical emergency and exploratory laparoscopy is indicated in all patients with suspected ovarian torsion. Delays in treatment may result in ovarian necrosis and infertility.
- Partial or complete twisting of the ovary and the fallopian tube around their supporting ligaments
- Also known as adnexal torsion or tubo-ovarian torsion
Ovarian enlargement is the most important risk factor; common causes include:
Ovarian cysts, especially: 
- Cysts > 5 cm
- Dermoid cysts (teratoma)
- Ovarian tumors
- Ovarian hyperstimulation syndrome
- Pregnancy: especially following assisted reproductive technology 
- Ovarian cysts, especially: 
- Long ovarian ligaments and laxity of pelvic ligaments (e.g., suspensory ligament) may be predisposing factors, especially in adolescents. 
- Strenuous physical activity 
- History of pelvic inflammatory disease
- Previous pelvic surgery, e.g., tubal ligation or hysterectomy 
- Twisting of the ovary and the fallopian tube around the infundibulopelvic ligament and ovarian ligament → compression of the ovarian veins and lymphatics → ↓ venous and lymphatic outflow → edema of the fallopian tube and ovary
- Worsening edema of the fallopian tube → compression of the ovarian artery → ovarian ischemia and necrosis
- Friable necrotic ovarian tissue → hemorrhage
- Most common during reproductive years but can occur at any age 
- Sudden-onset unilateral lower abdominal and/or pelvic pain
- Nausea and vomiting
- Adnexal mass may be palpable
- Adnexal tenderness
- In partial ovarian torsion, abdominal pain may be intermittent or resolve spontaneously.
Pain due to ovarian torsion may resolve intermittently as a result of spontaneous detorsion.
- Urine or serum β-hCG: to rule out pregnancy
- Emergency preoperative diagnostics: CBC, coagulation panel, type and screen
A positive pregnancy test does not rule out torsion; an enlarged corpus luteum is a risk factor for torsion during pregnancy. 
Pelvic ultrasound with Doppler: imaging modality of choice 
- Approach: transvaginal (preferred) and/or transabdominal
- Indication: all patients with suspected ovarian torsion
- Supportive findings
- Enlarged, edematous ovary with decreased blood flow 
- Thickened fallopian tube
- Twisted vascular pedicle
MRI abdomen and pelvis with contrast 
- Indication: inconclusive findings on ultrasound
- Supportive findings
- Enlarged ovary with thickening of the ipsilateral fallopian tube
- Deviation of the uterus to the ipsilateral side
- Decreased contrast enhancement of the affected ovary
- Twisted vascular pedicle (whirlpool sign)
- Ascites (usually minimal)
CT abdomen and pelvis with IV contrast: not routinely recommended 
- Indication: inconclusive ultrasound findings and MRI is not available
- Contraindication: pregnancy
- Findings: similar to MRI
Consult gynecology immediately if ovarian torsion is clinically suspected, even if ultrasound findings are normal. 
Ovarian torsion is a frequently missed diagnosis; a delay in treatment may affect fertility and pose a medicolegal risk. 
- Ruptured or bleeding ectopic pregnancy
- Ruptured ovarian cyst
- Tuboovarian abscess
- Acute appendicitis
- See also: “Differential diagnosis of lower abdominal pain in young women”
The differential diagnoses listed here are not exhaustive.
Surgery with adnexal detorsion and preservation of ovaries is the mainstay of treatment.
Emergency exploratory laparoscopy: indicated in all patients with suspected ovarian torsion
Premenopausal women: adnexal detorsion and preservation of ovarian function
- Intraoperative findings: enlarged purple or blue-black ovary, twisted fallopian tube
- Oophorectomy should only be performed if the ovary is frankly necrotic or gangrenous. 
- Postmenopausal women: salpingo-oophorectomy 
- Additional procedures: based on intraoperative findings
- Ovarian cystectomy or drainage: in patients with ovarian cysts
Oophoropexy: utero-ovarian ligaments are plicated or the ovary is fixed to either the posterior abdominal or pelvic sidewall to decrease the risk of retorsion.
- Indications 
- Ovarian torsion in a patient with a single ovary
- Bilateral ovarian torsion
- Recurrent ovarian torsion
- Patient with risk factors for retorsion (e.g., polycystic ovaries)
- Oophoropexy of the contralateral ovary may be considered in high-risk patients.
- Indications 
- Premenopausal women: adnexal detorsion and preservation of ovarian function
- IV fluid resuscitation
- Antiemetics as needed
- Consider second-look laparoscopy if there is concern for ovarian gangrene. 
- Pelvic ultrasound may be used to evaluate follicular development a few weeks/months after detorsion.
- Prognosis: Viability may be preserved in ∼ 90% of cases even if there is intraoperative evidence of ovarian ischemia. 
Diagnostic laparoscopy should be performed if there is strong clinical suspicion for ovarian torsion despite inconclusive imaging findings.
Acute management checklist
- Urgent OB/GYN consult
- NPO and IV fluids
- Parenteral analgesics: Opioid analgesics are preferred.
- Order CBC, β-hCG, type and screen, coagulation panel.
- Confirm diagnosis with imaging (pelvic ultrasound preferred)
- Transfer to OR for laparoscopy and immediate adnexal detorsion.