Ovarian hyperstimulation syndrome (OHSS), the nightmare of ovulation promotion and the great enemy of ovarian stimulation in IVF treatment. In the battlefield, we need to know our enemy, and the more we know about OHSS, the better we can have the courage and ability to overcome it. Here reproductive medicine experts answer all your questions about OHSS. What is Ovarian Hyperstimulation Syndrome (OHSS)? OHSS is a group of discomforts that occur after a woman with ovulation problems has been medicated to stimulate ovulation in order to get pregnant, also known as “syndrome”. We call it a “complication”, which means that a problem occurs that the doctor does not want to occur in the medical treatment, but does occur. In general, without ovulation, there is little to no ovarian hyperstimulation syndrome. (Figure: Ovarian hyperstimulation under ultrasound) How many people will probably develop OHSS when receiving ovulation promotion?There are three levels of OHSS: mild, moderate, and severe. The incidence of mild is about 8% to 23%, moderate is about 1% to 7%, and severe may be less than 0.5%, although this is not an exact incidence. When does OHSS usually occur? OHSS usually occurs at the end of ovulation treatment, when your doctor gives you an injection of chorionic gonadotropin (hCG) to help the eggs to be expelled from the ovaries, 4-5 days after the injection; in the early stages of pregnancy after ovulation, the hCG secreted by the embryo will stimulate the ovaries to secrete more cytokines, causing OHSS to occur and worsen. what kind of changes will occur in your body during OHSS? The ovaries will become much larger than normal, and water in the blood will escape through small blood vessels into the stomach (pelvis, abdomen) or outside of the lungs (chest), and even under the skin, making many parts of the body swell up. What will I feel when I have OHSS? You may feel bloated, not wanting to eat, nausea and vomiting, diarrhea, a bigger stomach, weight gain, less urination, difficulty breathing, and even panic, a fast heartbeat, and an inability to sleep equally. Is OHSS dangerous? Mild cases are not too dangerous and can get better with only outpatient treatment, while moderate to severe ovarian hyperstimulation syndrome usually requires hospitalization and the most severe cases of OHSS can even be life-threatening! (Picture: Infusion therapy) Can you tell the severity of OHSS? If not, what should I do? As a patient, you may not be able to judge the severity of OHSS. If you receive ovulation promotion treatment and experience the various discomforts mentioned earlier, you should go to a regular hospital promptly and see an emergency room if the discomfort is severe. Are there any more serious problems with OHSS? If you feel a sudden and severe pain in your belly, either on one side or both sides, sometimes accompanied by severe nausea, dizziness and cold sweat, you should not be careless and should go to the regular hospital immediately to see the emergency room because you may have ovarian torsion or rupture, and if not treated in time, the ovaries may be surgically removed as a last resort. You should also pay attention to any pain on one side of your head, neck, lower back, arms or legs, and if so, you should also seek prompt medical attention to check whether blood clots have developed in your blood vessels. If a blood clot has grown, it needs to be treated promptly and can be life-threatening or leave incurable sequelae, such as hemiplegia, in the most severe cases. (Figure: Ovarian torsion in OHSS) OHSS is likely to occur in those people? Women who are young, thin, menstruate more than once every 40 days, have had OHSS before during ovulation promotion, and women who are prone to allergies are also relatively more likely to develop OHSS. Can OHSS be prevented? It can be prevented and experienced doctors will try to prevent it before it happens. Patients with anovulation who are overweight/obese due to polycystic ovary syndrome can avoid the use of ovulation-promoting drugs by improving ovulation through exercise + weight loss through diet control; use weaker ovulation-promoting drugs and reduce the dosage as much as possible; be monitored by an experienced doctor in a regular hospital with ultrasound; if OHSS has occurred before with a conventional ovulation-promoting regimen for IVF, it can be switched to OHSS under medical supervision. If you have experienced OHSS before, you can switch to a low-risk regimen such as microstimulation/ mild stimulation/ antagonist regimen under the guidance of your doctor; during the process of ovulation promotion, if the above symptoms of OHSS occur, terminate ovulation promotion, terminate IUI, take strict contraceptive measures, do not use or reduce the dose of hCG, switch to GnRH-a to promote follicular ovulation if possible, freeze all embryos for the time being, etc.; you can also use some prophylactic medication called “hydroxyethyl starch”. It is also possible to use some plasma substitute called “hydroxyethyl starch” to expand blood volume and prevent blood concentration. Do I need to be hospitalized if I have OHSS? Generally, mild OHSS does not require hospitalization, as long as you pay attention to your symptoms and severity, eat a diet high in protein, such as lean meat, fish and shrimp, yogurt, etc., drink more water, and pay attention to the frequency and amount of urination. (Figure: Pay attention to your diet) If the discomfort worsens and the amount of urine is low, you should consult a doctor promptly. Moderate-to-severe ovarian hyperstimulation syndrome is a condition that requires hospitalization. How should I cooperate with treatment during hospitalization for OHSS? The recovery time for OHSS is generally unpredictable, but the more severe or pregnant patients may require longer treatment time. 1. Patients should weigh themselves daily, measure the amount of fluids they drink, including soup, juice and water, as well as the amount of urine, and keep records; 2. Due to bloating and difficulty in breathing, patients may not want to eat, but they should still try to eat a high-protein diet that is easy to digest and eat fewer meals, which can increase the protein content in the blood and is beneficial to the treatment of the disease; 3. They can drink more water, at least If you really can’t eat, don’t drink too much water, soup and juice can’t replace drinking water; 4, if possible, move to the ground properly, even if you lie in bed, you can turn over frequently, so that you can avoid the blood flow too slow and the formation of blood clots in the blood vessels, once formed, the consequences can be very serious! Promptly and truthfully reflect various discomfort symptoms so that doctors can judge the changes in the condition, because if necessary, doctors will place a tube to drain fluid in the patient’s chest/abdominal cavity to drain the fluid from these places to improve our discomfort symptoms, never hide or say light chest tightness, abdominal distension and other symptoms because of the fear of placing the tube.