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Pregnancy can make OHSS symptoms worse, especially if you're carrying more than one baby. This happens because of rising hCG levels. The condition might seem hard to deal with, but there are ways to lower the risk. Doctors may choose low-dose medications or change the treatment plan to help prevent it. With good care, most women recover fully, and many still achieve healthy pregnancies. Understanding OHSS helps you make informed choices and leads to safer fertility treatment. It also improves the chances of a healthy outcome for you and your future family!
What is Ovarian Hyperstimulation Syndrome (OHSS)?
Ovarian Hyperstimulation Syndrome (OHSS) is a condition that can occur during fertility treatments such as in vitro fertilisation (IVF). It happens when the ovaries respond strongly to medications designed to stimulate egg production. As a result, the ovaries swell and produce an unusually high number of eggs. This might also cause fluid to leak into the abdomen.A woman usually releases a single egg in each menstrual cycle. For those facing infertility, hormonal treatments are often prescribed to encourage the production of multiple eggs. In some cases, the ovaries may become overly responsive to these medications, leading to OHSS. Recent medical advances have made OHSS less common, though mild cases still happen occasionally.
In Vitro Fertilisation (IVF)
IVF is a medical procedure to help you conceive. Doctors retrieve mature eggs from follicles within your ovaries. An egg is fertilised either by injecting a single sperm directly into it or by mixing it with sperm in a petri dish. The fertilised egg, or embryo, is then placed into your uterus, where it may implant and lead to pregnancy. IVF is commonly recommended for people facing fertility issues.Types of Ovarian Hyperstimulation Syndrome (OHSS)
Some types of OHSS are mild, while others can be more serious. It's important to recognise the different types for effective treatment.Mild OHSS
You may experience mild abdominal bloating and discomfort. Your ovaries enlarge from 5 to 12 cm as multiple follicles develop. This may cause nausea, vomiting, or diarrhoea. These symptoms are mild and go away on their own with adequate rest and hydration.Moderate OHSS
You notice more pronounced bloating, moderate abdominal pain, and possible nausea or vomiting. Your ovaries become larger, and fluid may begin to accumulate in your abdomen, a condition known as ascites. At this stage, symptoms need close monitoring by your doctor. This is when your doctor may detect ascites through an ultrasound.Severe OHSS
You face intense abdominal pain, significant bloating, shortness of breath, and rapid weight gain from fluid buildup in your abdomen or chest. There are also changes in blood volume, thicker blood due to hemoconcentration, clotting abnormalities, and reduced kidney function and perfusion.How Common Is Ovarian Hyperstimulation Syndrome (OHSS)?
In the past, about 10 per cent of women undergoing controlled ovarian stimulation for IVF developed OHSS. However, that figure has now dropped to under 5 per cent.Symptoms and Complications of Ovarian Hyperstimulation Syndrome (OHSS)
Below is a list of the most common symptoms and potential complications associated with OHSS.- Abdominal pain, nausea, and vomiting: Your ovaries may enlarge up to 25 cm, causing abdominal pain, nausea, and vomiting.
- Ascites and tight abdominal swelling: Fluid leaking from ovarian follicles or increased blood vessel leakage can cause ascites, a buildup of fluid in your abdomen. This leads to tight, uncomfortable swelling in your belly, making you feel bloated and heavy.
- Peritonitis (abdominal lining irritation): When ovarian cysts rupture, blood or inflammatory substances can irritate your abdominal lining, causing peritonitis. This can cause tenderness or pain in specific areas or across your entire abdomen.
- Sudden acute abdominal pain: Sharp, intense pain in your abdomen may be caused by ovarian torsion (where the ovary twists), internal bleeding, or a cyst that has burst. These are serious conditions and need immediate medical attention.
- Hypotension and hypovolemia: In some cases of OHSS, fluid leaks out from damaged blood vessels in and around the ovaries. This causes a major shift of fluid from the bloodstream into other parts of the body. As the fluid level in the vessels drops, it causes hypovolemia or low blood volume. This low blood volume can lead to hypotension, or low blood pressure. This can cause swelling, ascites, fluid buildup in the chest known as hydrothorax, or fluid buildup around the heart called hydropericardium.
- Shortness of breath or Dyspnea: Enlarged ovaries and ascites can restrict the movement of your diaphragm, making it hard to breathe.
- Increased risk of blood clots: Fluid loss and hemoconcentration create a higher risk of blood clots, known as a hypercoagulable state. Clots may form in veins, often in the neck, arms, or head.
- Electrolyte imbalances: Fluid loss and reduced kidney function can cause your body to retain sodium and water, leading to low urine output. This may also lead to high potassium levels and an increased risk of acidosis, where the blood becomes too acidic.
- Acute kidney failure: Reduced blood volume thickens your blood and may cause small clots in your kidneys, blocking blood flow to them. This can lead to acute kidney failure.
What Causes Ovarian Hyperstimulation Syndrome (OHSS)?
Key factors that can cause OHSS are mentioned below.- Human Chorionic Gonadotropin (hCG) is often used to trigger ovulation or support the luteal phase. hCG can overstimulate the ovaries. This can lead to the symptoms of OHSS.
- If you have PCOS, your ovaries are more sensitive to fertility drugs because of a higher number of follicles. This makes you more prone to OHSS during treatment.
- High estradiol levels due to multiple developing follicles can indicate an overly strong ovarian response. This hormone surge contributes to OHSS.
- If you become pregnant, particularly with multiple embryos, your body naturally produces more hCG. This can make OHSS worse or last longer as the increased hCG further stimulates your ovaries.
- Younger women or those with lower body weight often have more responsive ovaries. This heightened sensitivity to fertility drugs increases the chances of OHSS.
Diagnosis of Ovarian Hyperstimulation Syndrome (OHSS)
Diagnosing OHSS involves specific tests and exams to confirm the condition and assess its severity. Your doctor will use these methods to monitor your symptoms:- Physical exam: Your doctor checks for signs like abdominal bloating, tenderness, or weight gain.
- Ultrasound: An ultrasound scans your ovaries to detect enlargement or multiple follicles. It also checks for ascites to confirm OHSS and monitor cyst size over time.
- Chest X-ray: A chest X-ray may be used to look for fluid in your lungs or chest. This helps identify complications in severe OHSS cases affecting your breathing.
- Blood tests: Blood tests measure electrolyte levels, hormones and kidney function.
Treatment Options for Ovarian Hyperstimulation Syndrome (OHSS) Based on Severity
OHSS requires different treatments depending on its severity. The treatment approaches for mild, moderate, and severe OHSS are:- Mild OHSS: Treatment focuses on supportive care as needed. Mild OHSS can worsen to moderate or severe forms, especially if you become pregnant. Your doctor will monitor you for signs like increasing abdominal size, sudden weight gain, or discomfort. You’ll need regular checkups for at least two weeks or until your period begins.
- Moderate OHSS: Treatment includes close observation, bed rest, and making sure you stay hydrated with enough fluids. Your doctor will use an ultrasound to track the size of ovarian cysts and perform blood tests. If your fluid intake or output is less than 1000 ml per day, or if there’s a fluid imbalance of more than 1000 ml, it’s a concern. Improvement shows when cysts shrink on consecutive ultrasounds and symptoms ease.
- Severe OHSS: Treatment is urgent and requires expertise. Severe OHSS is rare but life-threatening, so immediate care is critical. You’ll need bed rest, frequent monitoring, and fluid balance checks every four hours. Treatment aims to stabilise blood volume, correct fluid and electrolyte imbalances, relieve complications like ascites or fluid in the chest, and prevent blood clots.
Prevention of Ovarian Hyperstimulation Syndrome (OHSS)
You can reduce the risk of OHSS during fertility treatments with specific strategies. These focus on minimising overstimulation and managing your body’s response.- Low-dose gonadotrophin protocols: Using low doses of follicle-stimulating hormone (FSH) stimulates your ovaries gently. This supports the growth of only a few dominant follicles and lowers the risk of OHSS.
- Coasting (soft landing): If your estradiol level is high above 3000 pg/ml and there are over 20 follicles in each ovary, your doctor might stop hCG for up to 3 days while still giving GnRH agonists. This lets larger follicles grow while smaller ones shrink, lowering OHSS risk without harming pregnancy chances.
- Modified ovulation trigger: Using lower hCG doses or replacing hCG with luteinising hormone (LH) or a GnRH agonist to trigger ovulation may reduce early OHSS.
- Cryopreservation of all embryos: Cryopreservation means freezing all the embryos after fertilisation for future use instead of placing them into the uterus right away. This step is often used to help prevent OHSS from getting worse. Your ovaries also get time to rest and recover.
- Nonsteroidal anti-inflammatory drugs: Low-dose aspirin may reduce OHSS risk by decreasing inflammation and ovarian changes.
FAQs
- What are the symptoms of OHSS?
Symptoms can include abdominal pain, bloating, nausea, vomiting, and fluid buildup in the abdomen (ascites). - Can OHSS be prevented?
Yes, the risk of OHSS can be reduced by using low-dose medications, adjusting the ovulation trigger, or freezing embryos for future use.
