Can ovarian torsion occur in pregnancy?

Ovarian Torsion in Pregnancy

Yes, ovarian torsion can definitely occur during pregnancy, with reported rates ranging from 3% to 12% in pregnant women with adnexal masses. 1

Epidemiology and Risk Factors

• Ovarian torsion is one of the most common gynecological emergencies during pregnancy, with a reported incidence of approximately 3% 2
• Torsion is most commonly seen in the first trimester of pregnancy due to progesterone stimulation 3, 2
• Infertility treatments, particularly ovarian stimulation during IVF, significantly increase the risk of adnexal torsion in early pregnancy 4, 3
• Adnexal masses undergoing torsion during pregnancy have a mean size of approximately 10 cm 1

Clinical Presentation and Diagnosis

• Pregnant patients with ovarian torsion typically present with acute lower abdominal pain, nausea, and vomiting 5
• A high index of suspicion must be maintained for pregnant patients with an adnexal mass and acute lower abdominal pain 1
• Ultrasound is the primary diagnostic tool, with transvaginal ultrasound showing a sensitivity of 83.3% for ovarian torsion 1
• Key ultrasound findings suggesting torsion include:
  • Unilaterally enlarged ovary (>4 cm or volume >20 cm³) 1
  • Central afollicular stroma with multiple uniform 8-12 mm peripheral follicles (found in up to 74% of cases) 1
  • Abnormal Doppler flow patterns 1
• Importantly, 38% to 60% of pregnant patients with torsion have normal Doppler flow on ultrasound, making the absence of flow abnormalities insufficient to rule out torsion 1

Diagnostic Challenges

• Signs of ovarian torsion on ultrasound have varying accuracy 1:
  • Ovarian tissue edema: 21% sensitivity, 100% specificity
  • Absence of intraovarian vascularity: 52% sensitivity, 91% specificity
  • Absence of arterial flow: 76% sensitivity, 99% specificity
  • Absence or abnormal venous flow: 100% sensitivity, 97% specificity
• Up to 5% of torsed ovaries have been reported to be of normal size 1
• In pregnant patients, MRI may be used when ultrasound findings are equivocal 1

Management

• Prompt surgical intervention is the only way to protect the ovary and preserve the pregnancy once ovarian torsion is diagnosed 4
• According to management guidelines, symptomatic adnexal masses with suspected torsion or rupture require immediate surgical intervention regardless of gestational age 1
• Laparoscopic surgery in early pregnancy is safe and should be encouraged once the diagnosis is confirmed 4
• Delaying surgery may lead to serious complications including:
  • Hemorrhagic and gangrenous changes requiring oophorectomy 4
  • Serious infection that could jeopardize both maternal and fetal health 4
  • Permanent loss of the affected ovary 3

Outcomes and Complications

• Patients with torsion in pregnancy are at risk of recurrence, with rates of 4% to 15% in the same pregnancy 1
• Higher recurrence rates are seen in patients who undergo surgical detorsion alone versus cyst drainage 1
• Some studies have found an increased risk of miscarriage and preterm delivery after torsion, while others have found no adverse maternal or perinatal outcomes 1
• Elective surgery for adnexal masses is safer than emergent surgery, with lower rates of fetal loss (1% vs 5%) and preterm birth (4% vs 12%) 1

Special Considerations

• For pregnant patients undergoing pelvic surgery, there is an increased risk of fetal loss, stillbirth, preterm birth, and low birthweight infants compared to the general population 1
• In cases where the corpus luteum is involved in torsion during early pregnancy, hormonal therapy may be required to support the pregnancy if the corpus luteum must be removed 3
• Ovarian torsion can occur in any trimester, including the third trimester, potentially leading to iatrogenic preterm delivery if surgical intervention is required 5