IUI is used when couples use sperm from a man who is not the woman partner to have a baby. This is called donor insemination (DI). DI is done when the male partner has no sperm or when the sperm quality is so low that his sperm cannot be used for conception, and in vitro fertilization is not an option.
Choosing to use donor sperm for intra-uterine insemination (IUI) or in vitro fertilization (IVF), enables pregnancy in women who are single or in same-sex relationships. For other couples with severe, untreatable male factor infertility, or in the cases when the male carries a hereditary disease that he does not wish to pass on, use of donor sperm becomes the treatment of choice as well.