The goal of IUI is to increase the number of sperms that reach the fallopian tubes and subsequently increase the chance of fertilisation.

IUI involves a laboratory preparation of a ejaculated semen sample ( fresh / frozen ) to separate the fast moving sperms from more sluggish or non motile sperms and then injecting the prepared semen sample in the uterus at the time of ovulation ( Natural / Assisted ) . 

It can be performed with your partners semen sample or the sample obtained from a donor semen. ( also known as donor IUI ) 

IUI cycles may be offered to you as a couple when you are using donated sperms for your treatment, when you as a couple are unable to perform intercourse , because of a physical disability or psychological issues. 

IUI can only begin when it has been confirmed by your fertility expert that your tubes are open and are in a healthy state. To confirm this certain procedures , may be involved like HSG , HyCoSy , and or Laparoscopy. 

Success rates of IUI largely depend upon the cause of Infertility for the couple and whether or not any fertility drugs are used for egg generation.