When men cannot produce live sperm (azoospermia) due to known (such as past chemotherapy, gene/chromosome disorders) or unknown reasons, an IUI or IVF cycle can be done using sperm from anonymous donors. Donor sperm is also used for achieving single parenthood or for same sex couples where one or both partners wish to be impregnated. There are numerous reputable donor sperm banks, and they make sperm donors go through strict medical and genetic screening. Most donor banks can deliver samples within 72 hours after your registration. For IUI or IVF, unwashed donor sperm sample is sufficient (or prepared for intracervical insemination) as the specimen will be again processed prior to its use in the IVF laboratory.