Thousands of women have fertility treatments including IVF every year. IVF has been proven to be safe over time. However, in very rare cases, there may be complications which can be serious. The drugs used for ovarian stimulation have mild side effects for some women. Including mild bruising and soreness at the injection site, headaches, an upset stomach, and mood swings. Another side effect is ovarian hyperstimulation syndrome (OHSS.) This happens when the ovaries produce many follicles and fluid may leak from the blood vessels into the abdominal cavity and lungs. Usually this is mild and resolves on its own without treatment. In severe cases OHSS can result in very enlarged ovaries, dehydration, and large amounts of fluid in the lungs and abdomen. Fertility doctors can moderate the amount of drugs being prescribed or alter the medication regimen if they see any indication of potential trouble.