Reproductive · Year 2 · from Reproductive
Case 3: Ovarian Hyperstimulation Syndrome Following Gonadotropin Therapy
Clinical Image
Source: Wikipedia - Ovarian hyperstimulation syndrome - CC BY-SA 3.0
Case Presentation
A 28-year-old woman with PCOS is undergoing her first IVF cycle. She responded vigorously to gonadotropin stimulation, with 28 follicles seen on monitoring ultrasound and estradiol level of 4,500 pg/mL. Due to her high response, a GnRH agonist trigger was used instead of hCG trigger to reduce OHSS risk, and all embryos were cryopreserved (freeze-all cycle) rather than performing fresh transfer. Despite these precautions, 5 days after oocyte retrieval, she presents with abdominal distension, bloating, nausea, and decreased urine output. Physical examination reveals a distended abdomen with shifting dullness consistent with ascites. Weight has increased 4 kg since retrieval. Laboratory studies show hematocrit 48% (elevated due to hemoconcentration), creatinine 1.3 mg/dL (mildly elevated), and sodium 128 mEq/L (low). Ultrasound shows enlarged ovaries (12 cm bilaterally) with multiple cysts and significant ascites. The diagnosis is moderate-to-severe ovarian hyperstimulation syndrome (OHSS). She is admitted for IV fluid resuscitation and close monitoring of fluid balance, renal function, and coagulation parameters. Thromboprophylaxis with low-molecular-weight heparin is initiated given the hypercoagulable state. Therapeutic paracentesis is performed, removing 2 liters of ascitic fluid with symptomatic improvement. Over 5 days, her symptoms gradually resolve as hCG levels (from the agonist trigger) decline. She is discharged and undergoes successful frozen embryo transfer 2 months later.
Key Learning Points
- OHSS is a potentially life-threatening iatrogenic complication of ovarian stimulation characterized by ovarian enlargement, third-spacing of fluid, hemoconcentration, and hypercoagulability
- Risk factors include PCOS, young age, low body weight, high antral follicle count, elevated estradiol levels, and large number of retrieved oocytes
- Prevention strategies in high-risk patients include GnRH agonist trigger (instead of hCG), freeze-all cycles (avoiding hCG from pregnancy), and dopamine agonists
- Management is supportive: IV fluids for intravascular volume depletion, paracentesis for tense ascites, thromboprophylaxis, and monitoring for complications (VTE, renal failure, respiratory compromise)