For every woman who is considering or currently undergoing egg donation, understanding Ovarian Hyperstimulation Syndrome (OHSS) is extremely important. It’s a potential side effect that can occur during the process — but don’t worry — with proper medical care and preventive measures, the risk can be greatly reduced.
In this article, I’ll explain what OHSS is in a simple and clear way. It’s one of the more common reactions seen during egg donation treatments, and it’s also a condition that doctors pay close attention to. While most cases are mild and self-recoverable, if not properly managed, OHSS can cause noticeable discomfort.
For egg donors, preventing OHSS is especially important. And if symptoms do appear, there’s no need to panic — we’ll also go over the typical recovery timeline, treatment options, and helpful dietary adjustments so you can get through the process safely, comfortably, and with peace of mind.
What Is Ovarian Hyperstimulation Syndrome (OHSS)?
Ovarian Hyperstimulation Syndrome (OHSS) is a potential complication that can occur during ovulation induction or stimulation treatments. In the egg donation process, medications are used to stimulate the ovaries to produce multiple eggs. OHSS occurs when the ovaries respond too strongly to these medications — in simple terms, it’s a side effect caused by excessive ovarian stimulation.
So, how exactly does OHSS happen?
When the ovaries are overstimulated, they release large amounts of a substance called Vascular Endothelial Growth Factor (VEGF). VEGF increases the permeability of blood vessels, causing fluids to leak out of the bloodstream and accumulate in the abdominal cavity — and in severe cases, even in the chest cavity — leading to symptoms such as abdominal bloating and fluid buildup (ascites or pleural effusion).
At the same time, because fluid leaves the blood vessels, the blood volume decreases, making the blood thicker and increasing the risk of blood clots (thrombosis).
In short, OHSS is the body’s overreaction to fertility medications, and while it can sound concerning, it’s generally preventable and manageable with proper monitoring and care.
Severity Levels of Ovarian Hyperstimulation Syndrome (OHSS)
The symptoms of Ovarian Hyperstimulation Syndrome (OHSS) can vary from mild to severe. Understanding these levels helps egg donors recognize early warning signs and seek medical help when necessary.
Mild OHSS Symptoms:
- Abdominal bloating or discomfort:
One of the most common early signs. You may feel tightness, fullness, or pressure in your lower abdomen. - Mild nausea or vomiting:
Some donors experience mild nausea, occasionally accompanied by vomiting. - Mild diarrhea:
Slight changes in bowel movement may occur due to hormonal effects. - Slight weight gain:
Caused by temporary fluid retention within the body.
Moderate OHSS Symptoms:
- Noticeable abdominal bloating and pain:
The discomfort becomes stronger, with a clear sense of fullness or heaviness. - Persistent nausea and vomiting:
The nausea continues and may interfere with eating or daily activities. - Shortness of breath:
Fluid accumulation in the abdomen can press against the lungs, making breathing more difficult. - Significant weight gain:
Rapid weight increase over several days due to retained fluids. - Decreased urination:
Ovarian swelling and fluid imbalance may reduce kidney output.
Severe OHSS Symptoms:
- Severe abdominal bloating and pain:
Extreme swelling and sharp pain that severely affect comfort and mobility. - Persistent, intense nausea and vomiting:
Unable to eat or drink, leading to dehydration and electrolyte imbalance. - Severe shortness of breath:
Difficulty breathing may require oxygen therapy or hospitalization. - Blood clot formation:
Thickened blood increases the risk of clots, which can cause leg swelling, pain, or chest pain. - Little or no urination:
Serious impairment of kidney function. - Abdominal or chest fluid accumulation:
Excess fluid may collect in the abdomen or chest, requiring medical drainage.
⚠️ Important Reminder:
OHSS symptoms typically appear a few days after egg retrieval and can worsen if pregnancy occurs.
If you experience any of the above symptoms after donation or upon learning you are pregnant, contact your doctor immediately.
Early intervention is crucial for a safe and smooth recovery.
Be Careful of OHSS — A Common Post-Egg Donation Reaction
During the egg donation process, ovulation-stimulating medication is used to help the ovaries produce multiple eggs. This controlled ovarian stimulation is an essential part of the procedure — but it’s also the main reason some donors may develop Ovarian Hyperstimulation Syndrome (OHSS).
While not every donor will experience OHSS, the risk is higher compared to a natural menstrual cycle because of the medications involved. For this reason, doctors always evaluate each donor’s health condition carefully and design a personalized stimulation protocol to minimize the chances of OHSS.
How to Tell If You Might Have OHSS?
Early or mild symptoms of OHSS include:
- Abdominal bloating or swelling
- Water retention and puffiness
- Sudden weight gain
- Nausea
- Decreased urination
If the condition progresses to moderate or severe OHSS, symptoms may include:
- Sharp or persistent abdominal pain
- Difficulty breathing
- Very little urine output
- Chest fluid buildup or blood clots
⚠️ Seek immediate medical care if you notice:
- Chest tightness or shortness of breath
- Dark-colored urine
- Leg swelling
- Rapid weight gain of more than 1–2 kg per day
Who Is More Likely to Develop OHSS?
Although any woman undergoing ovulation induction can develop OHSS, certain groups are at higher risk, including:
- Younger women:
The ovaries of younger donors tend to respond more strongly to stimulation. - Women with Polycystic Ovary Syndrome (PCOS):
Their ovaries are more sensitive to hormones, making overstimulation more likely. - Those using higher doses of fertility medications:
The greater the medication dosage, the higher the OHSS risk. - Women who become pregnant during or shortly after stimulation:
Pregnancy can naturally elevate hormone levels, worsening OHSS symptoms.
Further Reading: Why Does Ovulation Pain Happen?How Is It Different From the Pain Caused by Ovulation Injections During Egg Donation?
How Long Does Ovarian Hyperstimulation Syndrome (OHSS) Last?
Treatment, Recovery, and Dietary Guidance:
For women who are considering or have already undergone egg donation, understanding the risks of Ovarian Hyperstimulation Syndrome (OHSS) is essential. While most cases of OHSS are mild and self-limiting, a small number may progress to severe symptoms that require close medical attention — and in rare cases, can be life-threatening.
After egg retrieval, early signs of OHSS usually appear within 1–3 days, with symptoms often peaking around the 7th day. In most mild cases, discomfort resolves naturally within 10–14 days as hormone levels drop and the body rebalances fluid levels.
However, if OHSS develops during or after pregnancy, symptoms may persist for several weeks — sometimes up to a month, since pregnancy hormones (especially hCG) can prolong the condition.
Common Symptoms of Ovarian Hyperstimulation Syndrome (OHSS)
In the early stages of Ovarian Hyperstimulation Syndrome (OHSS), women commonly experience abdominal bloating, swelling, weight gain, or reduced urination.
If the condition worsens, symptoms may progress to abdominal pain, shortness of breath, chest tightness, leg swelling, or dark-colored urine — all of which require prompt medical attention.
How Doctors Diagnose OHSS?
In addition to observing your symptoms, doctors use several diagnostic methods to confirm the presence and severity of OHSS:
- Medical history review:
Your doctor will ask about your medication history, when the symptoms began, and how severe they are. - Physical examination:
The abdomen will be checked for tenderness, swelling, or signs of fluid buildup. - Ultrasound examination:
Ultrasound imaging helps assess ovarian size, detect cysts, and identify whether there is fluid accumulation in the abdomen (ascites). - Blood tests:
Bloodwork is used to evaluate electrolyte balance, kidney and liver function, and blood viscosity, all of which can indicate the degree of fluid imbalance or dehydration.
Treatment for Ovarian Hyperstimulation Syndrome (OHSS):
From Home Care to Medical Intervention:
The treatment of Ovarian Hyperstimulation Syndrome (OHSS) depends on its severity. Most mild to moderate cases can be managed at home with careful monitoring, while severe cases require hospitalization and more intensive medical care.
Mild to Moderate OHSS:
Most women with mild or moderate OHSS recover naturally within 1–2 weeks. The focus is on supportive care and symptom management, which includes:
- Hydration and electrolyte balance:
Drink plenty of water and electrolyte beverages to prevent dehydration. - Adequate salt and protein intake:
Incorporate protein-rich foods (fish, eggs, tofu, chicken) and moderate salt to maintain fluid balance. - Gentle activity:
Avoid strenuous exercise, but light walking helps circulation and reduces clot risk. - Daily monitoring:
Measure body weight and abdominal circumference each day to track fluid retention. - Pain or clot prevention medication:
Over-the-counter pain relievers like acetaminophen can ease discomfort. Some cases may require anticoagulants to prevent blood clots.
Severe OHSS:
If symptoms worsen or do not improve, hospitalization is necessary for medical intervention and monitoring. Treatment may include:
- Intravenous (IV) fluids to restore hydration and electrolyte balance
- Albumin infusions to help stabilize blood volume
- Anticoagulant medications to reduce the risk of thrombosis
- Drainage of ascitic or pleural fluid (paracentesis or thoracentesis) if significant fluid buildup causes pain or breathing difficulty
- Medications such as Cabergoline or GnRH antagonists to suppress ovarian activity and prevent further stimulation
In rare cases, surgical intervention may be required if complications such as ovarian torsion, internal bleeding, or persistent fluid accumulation occur.
Diet + Daily Monitoring: Helping OHSS Recovery Happen Faster
- High-salt, high-protein diet:
Choose foods with >1,000 mg sodium and >25 g protein (e.g., soups, nuts, steak) to help replenish fluid that has leaked into body cavities and reduce edema. - Adequate electrolytes and salty snacks:
Opt for sports drinks, coconut water, and lightly salted crackers to avoid diluting body salts by drinking only plain water. - High-fiber, light meals:
Eat more vegetables, fruits, whole grains, yogurt, and omega-3–rich fish, which can ease constipation and inflammation. - Daily self-monitoring:
Track body weight, abdominal circumference, urine volume, and urination frequency. If you notice sudden spikes in measurements or reduced urine output, contact your medical team immediately.
How to Prevent Ovarian Hyperstimulation Syndrome (OHSS) During Egg Donation?
While Ovarian Hyperstimulation Syndrome (OHSS) is a known risk associated with egg donation, proper prevention and close medical monitoring can significantly reduce both its likelihood and severity. For egg donors, understanding and following these preventive strategies is essential to ensure a safe and comfortable process.
1. Comprehensive Pre-Treatment and Risk Evaluation:
- Detailed medical history:
Your doctor will review your personal and family medical background — especially any ovarian or endocrine conditions — to assess your OHSS risk. - Baseline testing:
Blood tests such as AMH (Anti-Müllerian Hormone), E2 (Estradiol), and AFC (Antral Follicle Count) help evaluate ovarian reserve and predict medication response.
Women with higher AMH levels generally have good ovarian reserve but are also more likely to overrespond to stimulation, increasing OHSS risk. - Personalized medication protocol:
Based on your age, body weight, and ovarian test results, your doctor will design a tailored stimulation plan and dosage. Using overly high doses of stimulation medication is avoided to minimize the risk of OHSS.
2. Careful Monitoring During the Stimulation Cycle:
- Regular ultrasound scans:
Ultrasound helps track follicle development, number, and size, allowing early detection of ovarian overstimulation. - Blood hormone testing:
Regular estradiol (E2) monitoring helps assess ovarian response. If levels rise too quickly or too high, your doctor can adjust or pause treatment to ensure safety. - Medication adjustments:
Based on ultrasound and blood results, your doctor may reduce dosage, delay injections, or even cancel the cycle if OHSS risk becomes too high.
3. Choosing the Right Trigger Shot:
The trigger injection (to induce final egg maturation) plays a major role in preventing OHSS:
- hCG (Human Chorionic Gonadotropin):
The traditional trigger shot, but it may increase OHSS risk due to its strong hormonal effect. - GnRH agonist (GnRH-a):
A safer alternative that significantly lowers the chance of OHSS, especially for high-risk patients. - Dual Trigger (hCG + GnRH-a):
Combines both methods to optimize egg maturity while still reducing OHSS risk — suitability depends on your individual case and must be determined by your doctor.
4. Post-Egg Retrieval Prevention Measures:
- IV hydration:
After retrieval, your doctor may recommend intravenous fluids to maintain hydration, electrolyte balance, and reduce OHSS symptoms. - Albumin infusion:
For high-risk donors, albumin may be administered to help maintain blood vessel stability and reduce fluid leakage into the abdomen. - Oral medications:
Drugs like Cabergoline can suppress VEGF (Vascular Endothelial Growth Factor) release, which decreases blood vessel permeability and helps prevent OHSS-related swelling and fluid buildup.
5. Dietary and Lifestyle Support:
- High-protein diet:
Eat more protein-rich foods such as eggs, fish, lean meat, and tofu to help maintain blood volume and osmotic balance, reducing fluid accumulation. - Electrolyte replenishment:
Drink beverages containing electrolytes, such as sports drinks or coconut water, to maintain proper hydration and mineral balance. - Avoid diuretic foods:
Reduce intake of coffee, tea, watermelon, and other diuretic foods to prevent excessive fluid loss.
6. Continuous Self-Monitoring and Follow-Up:
- Track your weight daily:
Rapid weight gain may indicate fluid retention — if this happens, contact your doctor promptly. - Observe urination:
Note any significant decrease in urine output, which may signal impaired kidney function. - Watch for warning symptoms:
If you experience abdominal bloating, pain, nausea, vomiting, or difficulty breathing, return to the clinic immediately for evaluation.
OHSS (Ovarian Hyperstimulation Syndrome) — Common Q&A
Q1: Does egg donation always cause Ovarian Hyperstimulation Syndrome (OHSS)?
Not necessarily. While egg donation does increase the risk of OHSS, not every donor will develop it.
The likelihood depends on several factors — including your body’s response to stimulation medications, dosage levels, and individual physiology.
With thorough pre-treatment evaluation, close monitoring during stimulation, and preventive care after egg retrieval, the chances and severity of OHSS can be significantly reduced.
Always communicate openly with your doctor to understand your personal risk and follow medical instructions carefully.
Q2: What should I do if I experience mild OHSS symptoms, like bloating after egg donation?
If you feel mild abdominal bloating after egg retrieval, it may be an early sign of mild OHSS — but don’t panic. You can help your body recover with the following steps:
- Get enough rest: Avoid strenuous exercise and allow your body to recuperate.
- Eat a high-protein diet: Protein helps maintain proper fluid balance within blood vessels.
- Stay hydrated with electrolytes: Drink sports drinks or coconut water to replenish electrolytes.
- Track your weight and urination: Weigh yourself at the same time each day and note urine volume.
Most importantly, contact your doctor immediately and describe your symptoms. Your doctor will advise on next steps based on your condition.
⚠️ Do not self-medicate or delay seeking medical care.
Q3: If I use a GnRH-a trigger instead of hCG, does that mean I won’t get OHSS?
Using a GnRH-a trigger instead of the traditional hCG trigger does significantly reduce the risk of OHSS — but it does not eliminate it completely.
GnRH-a works differently by lowering the release of Vascular Endothelial Growth Factor (VEGF), which helps reduce vascular permeability and the severity of OHSS.
However, every individual’s body reacts differently. Even with GnRH-a, a small risk of OHSS remains, particularly for women with high ovarian sensitivity or very strong medication response.
Further Reading:
👉 Is Egg Donation Dangerous? The Complete Egg Donation Process You Should Know
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