From the Guidelines
Ovarian hyperstimulation syndrome (OHSS) should be diagnosed and treated promptly, with a focus on preventing thrombotic complications, particularly in patients with antiphospholipid antibody syndrome (aPL), through the use of prophylactic anticoagulation with low molecular weight heparin (LMWH) such as enoxaparin 40mg daily, as recommended by recent guidelines 1. The diagnosis of OHSS involves a combination of clinical symptoms, physical examination, laboratory tests, and ultrasound findings, including ovarian enlargement, ascites, hemoconcentration, electrolyte imbalances, and symptoms like abdominal pain, bloating, nausea, and shortness of breath. Treatment options vary based on the severity of OHSS:
- Mild cases can be managed through outpatient monitoring, adequate hydration (2-3 liters of fluid daily), and pain management with acetaminophen or NSAIDs.
- Moderate OHSS may require closer monitoring of weight, urine output, and abdominal circumference.
- Severe cases often necessitate hospitalization for intravenous fluids, electrolyte correction, and possibly paracentesis to relieve ascites. Key to managing OHSS, especially in patients at increased risk of thrombosis like those with aPL, is the use of thromboprophylaxis, with LMWH being the preferred choice due to its efficacy and safety profile 1. Prevention strategies are also crucial and include:
- Individualized ovarian stimulation protocols to minimize the risk of OHSS.
- Use of GnRH antagonists.
- Triggering final oocyte maturation with GnRH agonists instead of hCG when possible.
- Considering "freeze-all" embryo strategies to avoid pregnancy-related hCG exposure, which can exacerbate OHSS. The pathophysiology of OHSS, involving increased vascular permeability triggered by vasoactive substances like VEGF released from hyperstimulated ovaries, underlines the importance of prompt and effective management to prevent complications such as thrombosis and renal failure 1.
From the Research
Diagnosis of Ovarian Hyperstimulation Syndrome (OHSS)
- OHSS is a rare iatrogenic complication of ovarian stimulation occurring during the luteal phase or during early pregnancy 2
- The clinical course of OHSS may involve electrolytic imbalance, neurohormonal and haemodynamic changes, pulmonary manifestations, liver dysfunction, hypoglobulinaemia, febrile morbidity, thromboembolic phenomena, neurological manifestations, and adnexal torsion 2
- Diagnosis is based on symptoms such as abdominal distension, abdominal pain, nausea, and vomiting, with ascites, pleural fluid, leukocytosis, hemoconcentration, and hypercoagulation 3
Treatment Options for OHSS
- Treatment of the acute phase relies on an empirical and symptomatic approach, with a general approach adapted to the levels of severity 2
- Specific approaches such as paracentesis, pleural puncture, and surgical approach of OHSS may be evaluated sporadically 2
- Dopamine agonists have shown significant evidence of their efficacy in the prevention of moderate and early-onset OHSS, with a recommended regimen of 0.5 mg of cabergoline for 8 days or rectal bromocriptine at a daily dose of 2.5 mg for 16 days 4, 5
- Anticoagulant treatment with heparin and thromboprophylaxis may be used to prevent thrombosis, which is a common complication of OHSS 6
- Rehydration, albumin infusion, and correction of electrolyte disorders may be used to treat moderate to severe cases of OHSS, with close monitoring of vital signs and dynamic ultrasound monitoring 3
Prevention of OHSS
- Identification of patients at risk and preventive measures of OHSS are the best means of reducing the risk of thrombosis after ovarian stimulation 6
- Dopamine agonists may be used to prevent OHSS in patients at high risk, with a recommended starting time on the day of hCG injection or preferably a few hours earlier 4
- Properly conducted studies, including large numbers of patients, are required to determine the best method of prevention and management of OHSS 2