Insemination is the procedure by which the sperm of the partner (homologous insemination) or a donor, where necessary (heterologous insemination), is deposited directly into the woman’s uterus. In insemination, the sperm is processed in the lab, so that the most mobile and normal sperm are transferred. The processed sperm is deposited into the uterus transvaginally using a special fine catheter, and it is a completely painless process. The method may be combined with ovarian stimulation with medication. Intrauterine insemination, when indicated, is the first choice in treating infertility, since it is not invasive and is less costly in comparison to IVF.