Having an IUI is a very safe and simple fertility procedure. There is an increased chance of having a multiple pregnancy, such as twins or triplets, which have higher miscarriages and other problems in pregnancy. This is more likely if fertility drugs have been used to encourage egg development. There is also a tiny (1/1000) chance of getting a pelvic infection or having overstimulation of the ovaries OHSS. OHSS or ovarian hyperstimulation syndrome is a condition often requiring hospitalization, with many cysts on the ovaries and fluid in the abdomen.