Sperm is generally not contaminated during IVF retrieval. Sperm is usually obtained by masturbation. For men with obstructive azoospermia or those who are unable to obtain sperm by masturbation, sperm can also be considered to be extracted by testicular or epididymal puncture under local anesthesia. The obtained sperm will be put into a disposable test tube cup and then transferred to the laboratory bench for a series of treatments such as sperm washing, centrifugation, etc. After the treatment, the extracted useful sperm will be combined with the egg for fertilization, and all these procedures are carried out under sterile conditions, so there is no need to worry about sperm being contaminated. Before semen extraction, men need to pay attention to rest as much as possible, keep a good enough sleep, relax, clean the genitals thoroughly and pay attention to hygiene.