Ovarian Hyperstimulation Syndrome (OHSS) is a complication of fertility treatments that stimulate the ovaries to produce multiple eggs. This occurs when ovaries overreact to hormonal medications, causing them to swell and leak fluid into the body. While often associated with egg retrieval in procedures like in vitro fertilization (IVF), OHSS can also develop following other ovulation-inducing treatments.
Understanding OHSS Risk
OHSS occurs when ovarian blood vessels become permeable, allowing fluid to shift from the bloodstream into the abdominal cavity and, in severe instances, other body compartments. This fluid accumulation leads to symptoms like abdominal discomfort, bloating, and rapid weight gain. The severity of OHSS ranges from mild (slight weight gain, abdominal pain) to severe, involving significant fluid buildup, severe pain, and complications like blood clots or kidney issues.
Certain factors increase an individual’s susceptibility to developing OHSS. Women who produce a large number of eggs during ovarian stimulation, often exceeding 15-20 follicles, face a higher risk. Individuals with Polycystic Ovary Syndrome (PCOS) are also more prone to OHSS due to their inherent ovarian sensitivity to hormonal stimulation. Other risk factors include being under 35 years old, having a low body weight, and exhibiting high or rapidly increasing estrogen levels during the stimulation phase. A history of previous OHSS episodes also indicates an increased future risk.
Medical Approaches to Prevention
Fertility specialists employ several medical strategies to minimize OHSS risk. One significant approach involves the type of “trigger shot” used to induce final egg maturation before retrieval. While human chorionic gonadotropin (hCG) has traditionally been used, it can increase OHSS risk due to its long half-life and its role in causing ovarian blood vessels to become more permeable.
Alternatively, a GnRH agonist trigger (such as leuprolide) can be used, particularly in cycles utilizing a GnRH antagonist protocol. This trigger induces a short, self-limited surge of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which significantly reduces OHSS risk by shortening ovarian stimulation and promoting a rapid decrease in estrogen levels. This method helps prevent the release of substances like vascular endothelial growth factor (VEGF), which contribute to fluid leakage.
Individualized stimulation protocols are tailored to a patient’s specific risk profile. This may involve using lower starting doses of gonadotropins, the injectable hormones that stimulate egg production, especially for individuals with risk factors. Fertility clinics closely monitor follicle development via ultrasound and hormone levels through blood tests, adjusting medication dosages to achieve an optimal response without overstimulation. In some cases, “coasting” is employed, where gonadotropin medications are temporarily withheld while continuing GnRH antagonist administration, allowing estrogen levels to decrease before the trigger shot.
Specific medications, known as dopamine agonists, are sometimes administered to high-risk patients to prevent or reduce OHSS severity. Cabergoline is a commonly used dopamine agonist that helps to reduce fluid leakage from blood vessels. Studies suggest that cabergoline can lower the incidence of moderate to severe OHSS in high-risk women, typically administered at a dose of 0.5 mg daily for about 8 days, starting around the time of the hCG injection.
Personal Strategies for Prevention
Beyond medical interventions, individuals can adopt personal strategies to support their body’s recovery and potentially mitigate OHSS severity. Maintaining adequate hydration is important, as fluid shifts in OHSS can lead to dehydration. Drinking plenty of water and electrolyte-rich beverages, such as sports drinks, helps to balance fluid levels and support kidney function. Consume enough fluids to ensure urine remains pale yellow.
Dietary adjustments also play a role in managing fluid balance. A diet rich in protein, aiming for 80-100 grams daily, can help maintain fluid within the bloodstream, preventing accumulation in tissues. Lean meats, eggs, dairy, and legumes are good sources of protein. Limiting sodium intake can also be beneficial, as high salt consumption may contribute to fluid retention and electrolyte disturbances. Avoiding strenuous physical activity after egg retrieval is generally recommended to allow the ovaries to recover and prevent potential injury or discomfort.
Post-Retrieval Monitoring and Early Action
Vigilant monitoring for symptoms after egg retrieval is important for early detection and management of OHSS. Mild symptoms, such as abdominal bloating, discomfort, nausea, and slight weight gain (more than 2 pounds per day), are common and often resolve on their own within a week. However, it is important to distinguish these from more concerning signs.
Rapid weight gain, specifically more than 2.2 pounds (1 kilogram) in 24 hours or 5 pounds overnight, severe abdominal pain, persistent nausea and vomiting, decreased urination, or shortness of breath are signs that warrant immediate medical attention. Other severe symptoms include a tight or enlarged abdomen, and in rare cases, leg pain or chest pain, which could indicate a blood clot. Contacting the fertility clinic or seeking emergency care without delay is important if these symptoms arise, as early detection can help prevent progression to severe OHSS and its complications.