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Women's Health

Ovarian Torsion

Twisting of the ovary and tube on their vascular pedicle occludes venous outflow first and then arterial inflow, so the ovary congests and infarcts.

In a nutshell

Ovarian torsion is twisting of the ovary and tube on their vascular pedicle, and it is a surgical emergency. Give morphine 5 mg by slow intravenous injection, do a pregnancy test, and get the patient to theatre without waiting for imaging to be conclusive.

Classic presentation

A 25-year-old woman with a known ovarian cyst has sudden severe right iliac fossa pain radiating to the thigh, vomiting, and a tender adnexal mass.

Key points

  • There is no UK national guideline for ovarian torsion. Green-top Guideline 62, from the Royal College of Obstetricians and Gynaecologists, excludes the acute presentation.
  • The white cell count and CRP are raised in only 50 per cent of women with ovarian torsion, so normal bloods mean nothing.
  • NHS Borders is the only readable UK source giving a size: consider surgery for a premenopausal simple cyst over 7 cm because of torsion risk.
  • Torsion complicates 1 to 3 per cent of ovarian cysts found in pregnancy, and becomes unusual after 20 weeks of gestation.
  • More than 48 hours from symptom onset is associated with poor ovarian outcomes, but no UK source sets a salvage cut-off.
  • Ovarian hyperstimulation syndrome (OHSS) raises the risk, most of all in pregnancy. Torsion is one of the few reasons to operate in OHSS.
  • In prepubescent girls torsion happens with no adnexal pathology at all, and the scan often shows peripherally arranged follicles.

First-line investigation

A urine pregnancy test in every girl or woman of reproductive age, then urgent transvaginal or transabdominal ultrasound with colour Doppler.

Management

Recognise it and escalate

  • Admit to acute gynaecology. ABCDE (airway, breathing, circulation, disability, exposure), intravenous access, nil by mouth. Registrar to assess promptly, consultant early. Do not wait for a scan slot.1
  • Morphine 5 mg by slow intravenous injection every 4 hours, adult or ages 12 to 17. Add paracetamol 1 g by mouth or intravenously, 4 to 6 hourly, up to 4 g in 24 hours.7,8
  • Cyclizine 50 mg by mouth, intramuscularly or intravenously, up to three doses a day. Morphine needs a lower dose in the frail, the elderly and in renal impairment.9,7
  • Urine pregnancy test in everyone of reproductive age (NICE NG126 1.4.5). If positive with pain and pelvic or cervical motion tenderness, refer immediately to the early pregnancy assessment service (1.4.7).6

Image, but do not be gated by it

  • Urgent transvaginal or transabdominal ultrasound with colour Doppler. Lack of out-of-hours scanning must not delay management; ask the on-call consultant for a bedside scan.1
  • A normal scan does not exclude torsion, and the decision to operate may rest on clinical grounds alone when symptoms are severe.1
  • Full blood count, U&E, LFT, CRP, and group and save. The white cell count and CRP are raised in only 50 per cent of cases.1

Theatre, detorsion and conservation

  • Emergency theatre list (the CEPOD list) in the next appropriate space. Do not wait for a gynaecological oncology multidisciplinary team discussion. No UK source sets an hours target.1,3
  • Laparoscopic detorsion with ovarian preservation where feasible. BritSPAG's black-ovary rule is paediatric; adult guidance says appearance predicts recovery poorly. Consent must cover possible oophorectomy.2,3
  • Oedematous tissue makes cystectomy hazardous, so the cyst may be removed at an interval operation. Reserve oophorectomy for a clearly necrotic ovary or suspected malignancy.2,3

Pregnancy and fertility treatment

  • In pregnancy, operate for an acute abdomen or suspected malignancy; elective intervention waits until 14 to 16 weeks. Torsion becomes unusual after 20 weeks.1
  • Ovarian hyperstimulation syndrome (OHSS) raises torsion risk, most of all in pregnancy. Torsion, rupture and ectopic pregnancy are the only reasons to operate in OHSS.10

After surgery

  • Ondansetron 4 mg intramuscularly or by slow intravenous injection for postoperative nausea. Codeine phosphate 30 to 60 mg every 6 hours as required, maximum 3 days.11,12
  • Histology on the cyst or ovary, gynaecology follow-up for ovarian function and recurrence, and paediatric and adolescent gynaecology review with fertility counselling for a child.2,1
  • BritSPAG says oophoropexy remains controversial with limited long-term data and is generally not recommended. No readable UK source gives a salvage or recurrence rate.2

Exam traps

  • Preserved Doppler flow does not exclude torsion: the twist may be partial or intermittent, and the ovary has two sources of arterial supply.
  • Do not remove a blue-black ovary reflexively. Appearance predicts recovery poorly, but the explicit black-ovary conservation rule comes from paediatric guidance, not a national adult guideline.
  • There is no ovarian six-hour rule. That figure belongs to testicular torsion, and no UK source gives an ovarian equivalent.
  • Normal white cell count and CRP are found in half of confirmed cases, so normal bloods never stand a patient down.
  • The BNF lists acute abdomen among morphine's contra-indications; give opioid analgesia with the surgical team involved rather than withholding it during investigation.
  • Cervical motion tenderness is common in torsion and does not by itself make the diagnosis pelvic inflammatory disease.
  • Resolving pain does not mean the ovary is safe: torsion can be intermittent, and previous identical episodes raise the risk.

Illustrations

Preserved colour Doppler flow in ovarian torsionExample labelled ovarian torsion, with an enlarged cystic ovary and persisting peripheral colour signals. Preserved flow does not exclude torsion; interpret ultrasound alongside symptoms and urgent gynaecological assessment.Nevit Dilmen, Wikimedia Commons · CC-BY-SA-3.0

Key sources

  1. NHS Borders, Ovarian cysts/masses management (Right Decision Service) (The most detailed readable UK document on ovarian torsion. Source for presentation and examination findings, the white cell count and CRP being raised in only 50 per cent of cases, a normal scan not excluding torsion, the emergency (CEPOD) theatre list, the 48-hour association with poor ovarian outcomes, intraoperative appearance not predicting recovery, the over-7-cm surgical threshold, and the pregnancy figures. Its own editorial block reads last reviewed 31/07/2020 with a next review date of 31/07/2023, so it is past its own review date.)Updated 31 Jul 2020
  2. British Society for Paediatric and Adolescent Gynaecology (BritSPAG), Guideline for the management of ovarian cysts in children and adolescents, June 2017 (The only UK society guideline found that gives substantive torsion guidance, and it is written for children and adolescents. Source for torsion being one of the only indications for immediate surgery, untwisting rather than removing even a black, necrotic-looking ovary, interval cystectomy in fragile tissue, torsion without adnexal pathology in prepubescent girls, peripherally arranged follicles on ultrasound, oophoropexy being generally not recommended, and follow-up in a paediatric and adolescent gynaecology clinic.)Published 1 Jun 2017
  3. NHS Greater Glasgow and Clyde, Ovarian Masses in premenopausal adults, assessment and management (guideline 514), version 2 (Current UK board guideline, editorial block last reviewed 30/09/2025. Source for ovarian torsion being managed as an emergency with surgery not delayed to await gynaecological oncology multidisciplinary team discussion, for the possibility of oophorectomy being discussed, documented and consented before surgery, and for LDH, alpha-fetoprotein and hCG in women under 40 with a non-simple mass.)Updated 30 Sept 2025
  4. Royal College of Obstetricians and Gynaecologists (RCOG) and British Society for Gynaecological Endoscopy (BSGE), Management of Suspected Ovarian Masses in Premenopausal Women, Green-top Guideline No. 62, November 2011 (First edition, with the review process due to start in 2014, still listed as current on the RCOG Green-top index dated January 2026. Its scope statement says it does not specifically address the acute presentation of ovarian cysts. Its entire torsion content is one clause in section 4.1. Section 6.2 states there is no evidence-based consensus on the size above which surgical management should be considered, and that most studies used an arbitrary maximum diameter of 50 to 60 mm.)Published 1 Nov 2011
  5. Bailey et al., Ovarian torsion: a modern approach to management, The Obstetrician and Gynaecologist, 2025 (The principal UK review of this topic and very probably the best source on it. It could not be read: the publisher returned an empty response on 7 August 2026. It is listed so that a reader with journal access can find it. No statement in this chapter rests on it.)Published 9 Jun 2025
  6. NICE NG126, Ectopic pregnancy and miscarriage: diagnosis and initial management, Symptoms and signs of ectopic pregnancy and initial assessment (Recommendations 1.4.5 to 1.4.8: think about offering a pregnancy test to women of reproductive age even when symptoms are non-specific; all professionals caring for them should have access to pregnancy tests; refer immediately to the early pregnancy assessment service, or the out-of-hours gynaecology service, on a positive test with pain and abdominal, pelvic or cervical motion tenderness; and about a third of women with an ectopic pregnancy have no known risk factor.)Published 17 Apr 2019 | Updated 17 Jun 2026
  7. BNF, Morphine (Acute pain in an adult by slow intravenous injection: initially 5 mg every 4 hours, with a reduced dose in frail and elderly patients. Child 12 to 17 years by intravenous injection: 5 mg every 4 hours, given over at least 5 minutes. Acute abdomen is listed among the contra-indications for morphine. Avoid use or reduce the dose in renal impairment.)
  8. BNF, Paracetamol (Mild to moderate pain in an adult by mouth: 0.5 to 1 g every 4 to 6 hours, maximum 4 g per day. By intravenous infusion for body-weight 51 kg and above: 1 g every 4 to 6 hours over 15 minutes, maximum 4 g per day.)
  9. BNF, Cyclizine (Nausea and vomiting in an adult, by mouth, by intravenous injection or by intramuscular injection: 50 mg up to 3 times a day.)
  10. Royal College of Obstetricians and Gynaecologists (RCOG), The Management of Ovarian Hyperstimulation Syndrome, Green-top Guideline No. 5, third edition, February 2016 (Section 10.8: the risk of ovarian torsion or rupture appears to be increased in women with ovarian hyperstimulation syndrome, particularly in the presence of pregnancy, and surgery in OHSS is indicated only where there is a coincident problem such as adnexal torsion, ovarian rupture or ectopic pregnancy. This is the third-edition PDF still served by rcog.org.uk and read on 7 August 2026; a later edition may exist on the publisher's platform, which could not be read.)Published 1 Feb 2016
  11. BNF, Ondansetron (Treatment of postoperative nausea and vomiting in an adult, by intramuscular injection or by slow intravenous injection: 4 mg for 1 dose.)
  12. BNF, Codeine phosphate (Short-term treatment of acute moderate pain in an adult or a child aged 12 to 17 years, by mouth: 30 to 60 mg every 6 hours as required, for a maximum of 3 days.)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.