Bilateral ovarian torsion complicating a pregnancy via IVF-fresh ET was managed with surgical detorsion resulting in a live birth: a case report

Introduction

Ovarian torsion, a rare gynaecological emergency, is increasingly associated with assisted reproductive technology, with a 16% incidence in ovarian hyperstimulation syndrome (OHSS) while pregnancy accounts for 12%–25%.1 While more common on the right side, representing 64% of incidents, bilateral torsion is rare.2 Its nonspecific symptoms (eg, acute pain, nausea) can be masked by early pregnancy or OHSS which elevates the torsion risk. Prompt diagnosis via Doppler ultrasound is critical to preserve ovarian function. Ovarian torsion management has shifted from salpingo-oophorectomy to laparoscopic detorsion, aiming to restore ovarian blood flow. In addition, strategies to prevent postoperative recurrence are an important consideration in patient care.

This report details a rare case of bilateral ovarian torsion with OHSS in a fresh IVF pregnancy, successfully managed via laparoscopic detorsion, which preserved fertility and resulted in vaginal delivery.

Case presentation

A woman underwent three unsuccessful cycles of artificial insemination with her husband’s sperm before proceeding to IVF-ET. Transvaginal oocyte retrieval under ultrasound guidance was performed with an antagonist protocol. On the trigger day, the serum estradiol level was 2214.23 pg/mL. 20 oocytes were retrieved. A single 4AB-grade day-5 blastocyst was transferred in a fresh cycle. An ultrasound performed 28 days post-transfer confirmed an intrauterine singleton pregnancy.

At 45 days post-transfer, acute left lower abdominal pain, nausea and vomiting developed, lasting 9 hours. Findings on gynaecological examination were as follows: an anteverted uterus corresponding to 9 weeks’ gestation, tenderness in the left adnexa(+). Laboratory tests revealed a white blood cell count 10.61×10⁹ /L, haematocrit of 37.8%, serum albumin of 5.02 g/dL and normal hepatic and renal function. Transvaginal Doppler ultrasound revealed the left ovary measured 8.0×9.7 cm, and the right ovary measured 9.7×7.8 cm. The left ovary showed diminished flow signals at the vascular pedicle, with only scattered punctate signals visible. The preliminary diagnosis was ovarian torsion (left) and OHSS. Approximately 11 hours after the onset of abdominal pain, paracentesis was performed, draining 550 mL of blood-tinged ascitic fluid. Six hours after paracentesis, a laparoscopic exploration was performed due to persistent abdominal pain. Surgical findings revealed a 9-week gestation uterus. The left ovary exhibited 720-degree torsion with diffusely dark bluish-black tissue containing focal viable cortex, while the right ovary showed 90-degree torsion but appeared otherwise normal (figure 1A). The left ovary was gently elevated, restoring the normal anatomical position of the left adnexa. Several minutes after detorsion, focal reperfusion and an increased area of viable white cortex were observed, suggesting preserved viability (figure 1B). Similarly, the right ovary and fallopian tube were returned to their anatomical position. To prevent recurrent torsion, the right ovary was repositioned into the deep pelvic pouch of Douglas and placed beneath the left ovary in a “pillow-style” fixation termed the “padding underneath” (figure 2). Postoperative management comprised anti-inflammatory, anticoagulant and tocolytic therapy, with gradual reduction of ovarian size observed during follow-up. The patient was discharged on day 13 with a final diagnosis of bilateral ovarian torsion and moderate OHSS. The pregnancy progressed to 40 weeks and 4 days, culminating in the vaginal delivery of a live infant. This report was approved by the local Ethics Committee with patient consent obtained.

Discussion

A literature review identified only seven prior cases of ovarian torsion with OHSS in early pregnancy, managed with salpingo-oophorectomy without recurrence prevention. However, this bilateral torsion was successfully treated via detorsion and novel fixation, culminating in term delivery and offering management insights for post-IVF torsion.

Ovarian torsion requires prompt diagnosis given its nonspecific presentation, primarily acute abdominal pain with nausea/vomiting. The diagnosis of ovarian torsion is challenging in early pregnancy with OHSS, as symptoms may be obscured. On Doppler ultrasound, the absence or reduction of ovarian blood flow is a key diagnostic clue with high specificity. Studies indicate that a substantial reduction or complete absence of ovarian blood flow warrants surgical intervention. Doppler ultrasound has a false-negative rate of 61% for ovarian torsion in pregnancy; thus, torsion cannot be excluded despite normal findings.3

In clinical practice, ovarian torsion with OHSS in early pregnancy presents a complex clinical scenario and requires prompt management. First, we need to consider the treatment approach. Intermittent abdominal pain with an enlarged, low-flow ovary on Doppler ultrasound suggests incomplete ovarian torsion. A stepwise management approach is recommended, beginning with conservative treatment such as cyst aspiration or observation. Should symptoms persist, laparoscopic intervention is warranted. Due to our patient being accompanied by OHSS, we took conservative management with paracentesis. As this proved ineffective, surgical intervention was performed. Complete ovarian torsion requires surgical exploration once diagnosed. High suspicion of ovarian torsion in pregnancy justifies aggressive surgical intervention to prevent complications. Second, we need to regard the surgical approach and the timing of detorsion. The hypercoagulability associated with OHSS and early pregnancy raises theoretical concerns that detorsion of a torsed ovary might release preformed microthrombi, increasing the risk of thromboembolism. This risk was previously justified with oophorectomy to avoid thromboembolic events. However, recent studies have established that ovarian conservation after detorsion is not associated with an elevated thromboembolic risk.4 Moreover, the majority of ovarian torsion cases occur in patients of reproductive age, so making the preservation of ovarian tissue function and fertility capacity important. Nowadays, laparoscopic detorsion has emerged as the first choice for ovarian torsion. Oelsner et al recommend that ovarian detorsion should be the preferred procedure for young women, even in the presence of severe ischaemic changes.4 The standard intraoperative criteria for oophorectomy in ovarian torsion are a blackish-purple ovary with absent Doppler flow in its vessels and parenchyma, and no flow recovery within 15 min after detorsion. The optimal timing for surgical detorsion remains debated, with reports supporting both immediate intervention on diagnosis and a trial of conservative management first.5 In this case, after symptom onset, ultrasound demonstrated preserved ovarian blood flow, leading to initial conservative management with ascites aspiration. When this proved ineffective, surgery was performed within approximately 15 hours. Tsai et al suggested that detorsion should be performed within 24 hours of symptom onset for optimal outcomes,6 while Kazez et al have reported cases of successful ovarian salvage even after 48 hours of torsion.7 As documented in table 1, ovarian function was maintained in a case despite intervention occurring more than 24 hours after symptom onset.8–10 Therefore, the 24-hour mark should not be used as an absolute cut-off for performing detorsion, and surgical decisions should avoid being based solely on the assumption of irreversible ovarian necrosis. Clinical consensus advocates for initial detorsion followed by a 10–15 min observation period in all cases of complete torsion. If blood flow fails to return, oophorectomy should be performed.

The recurrence rate of ovarian torsion during pregnancy is reported to be as high as 19.5%,3 suggested to fix the ovary after ovarian torsion via sutured displacement, ligament plication or cystectomy, if applicable,5 to avoid retorsion postoperatively. The ovarian cysts in OHSS are characteristically luteinized and friable, but they usually regress spontaneously; therefore, cystectomy is not advised. We report the first use of an innovative intraoperative technique called “padding underneath”, the right ovary was positioned beneath the left within the pelvis to secure the ovary without sutures, thereby avoiding iatrogenic injury and bleeding; coupled with postoperative management, including an abdominal binder and activity limitation, this prevented recurrent torsion.

This case provides a reference for managing bilateral ovarian torsion with OHSS in early pregnancy, addresses the timing and feasibility of surgical detorsion, and offers insights transferable to similar cases.

Conclusion

Ovarian torsion, a rare but serious complication in IVF pregnancies often linked to OHSS, requires high clinical suspicion for prompt diagnosis. Management is tailored to severity: suspected incomplete torsion may allow brief conservative management, whereas complete torsion mandates immediate laparoscopy. Intraoperatively, detorsion is first-line therapy, followed by a 10–15 min observation for reperfusion; ovarian preservation is pursued if viability returns, with adnexectomy reserved for non-viable tissue. Crucially, detorsion should be attempted even with bilateral, ischaemic-appearing ovaries. To prevent recurrence, ovarian fixation or ligament plication is recommended. This study also introduces the novel use of a padding technique following detorsion to reduce recurrence risk.