What is OHSS and what warning signs should I watch for during IVF?

OHSS (ovarian hyperstimulation syndrome) is an over-response of the ovaries to fertility medication. The ovaries enlarge and fluid can shift out of blood vessels into the abdomen and sometimes the chest. Women with PCOS, a high AMH, many follicles or high estrogen levels are at higher risk, which is why your doctor is monitoring you closely. Mild OHSS is fairly common and includes bloating, mild abdominal discomfort and slight nausea. It usually settles on its own. Symptoms tend to appear after the trigger or retrieval and can worsen if pregnancy occurs, because pregnancy hormones stimulate the ovaries further. Go back to your centre or the nearest emergency department urgently if you notice: severe or increasing abdominal pain, a rapidly swelling abdomen, weight gain of more than about 1 kg in a day, passing much less urine, persistent vomiting, breathlessness, chest pain, leg swelling or dizziness. Doctors have several ways to lower the risk, such as adjusting doses, using a different trigger, or freezing all embryos and transferring later. Ask your doctor what they are planning in your case. Follow advice on fluids and activity, and don't wait to seek help if symptoms worsen.