Intrauterine insemination (IUI) It is a procedure in which sperms are “processed” and placed into the uterus through a fine catheter. The male partner produces a semen sample by masturbation. The sperms are separated from the seminal plasma, white blood cells, prostaglandins, and other “debris” which are normally filtered out during natural intercourse. A speculum is inserted into the woman’s vagina and a catheter with an attached syringe, containing the washed sperm, is inserted through the cervix into the uterus. The processed semen is placed in the uterus with a catheter very slowly.