Why IUI?

During intercourse, 1% of the sperm make it to the uterus, and another 1% make it to the tube; the place fertilization takes place. So most of the sperm doesn’t make it. Some get stuck, some die, some get lost (we’ve all heard jokes about that). In a fertile couple a small number of sperm in the tube is all that’s needed. By doing insemination (intrauterine insemination that is), we are playing a numbers game. More sperm are getting to the tube, so if one doesn’t do it, maybe the next one will. Insemination raise pregnancy rates by a few percentage points over having intercourse. Washing the sperm for insemination doesn’t make the sperm any stronger, it just allows us put it into the uterus. In an unwashed specimen, there are items that would cause intense cramping of the uterus, so we wash away seminal fluid (which contains prostaglandins) and dead sperm. Washing also lowers the bacteria counts.

-From Dr. Liccardi's blog