Ovarian hyperstimulation syndrome and pregnancy: what to know

Ovarian hyperstimulation syndrome, or OHSS, is a response to fertility medicines that stimulate the ovaries. The ovaries can enlarge, and fluid can move out of blood vessels into the abdomen. This may cause bloating, abdominal pain, nausea, and rapid changes in how you feel.

When pregnancy occurs, pregnancy hormones can continue stimulating the ovaries and may make OHSS last longer or worsen. Symptoms can overlap with ordinary early pregnancy symptoms, so do not try to judge severity from discomfort alone.

Tell your fertility clinic promptly if you have a positive pregnancy test and have had ovarian stimulation or embryo transfer. The team may arrange examinations, ultrasound, and blood tests, while checking your hydration, urine output, breathing, and abdominal symptoms.

Follow the clinic's instructions about fluids, activity, medicines, and appointments. Do not take anti-inflammatory medicine or change prescribed treatment without checking first. If you are considering treatment that separates embryo transfer from ovarian stimulation, ask whether frozen embryo transfer is appropriate for your plan.

Seek urgent medical care for difficulty breathing, chest pain, severe or increasing abdominal pain, repeated vomiting, very little urine, faintness, marked swelling, or sudden leg pain. These signs can indicate significant fluid shifts or a clot and should not wait for a routine appointment.

Ask which symptoms should be reported immediately, how often you need monitoring, and whether pregnancy changes your follow-up plan. Ask how your ovaries and fluid levels will be checked, which medicines are suitable, and whom to contact outside clinic hours.