A prerequisite for its implementation is that at least one fallopian tube is intact. At the time of ovulation, sperm cells from the partner are isolated by special procedures and introduced into the uterine cavity by means of a thin tube (catheter). The sperm then only have to make their way through the fallopian tubes to the egg(s), which increases the likelihood of egg fertilisation. Insemination is carried out if, for example, the number and mobility of the man's sperm cells are limited or only a reduced proportion of normally formed sperm cells are available.