Mr. Song in Guangzhou has recently been troubled by many things, one of the most annoying thing is that after a year and a half of marriage, his wife’s belly has not yet moved, and the elderly at home are urging to hold their grandchildren every day. The doctor told him that “Mr. Sperm” often plays hide-and-seek with him, the sperm inside the semen is sometimes absent, sometimes only after centrifugation to find, the chance of appearing seems to be related to the mood of “Mr.”. Therefore, Mr. Song went to all the male departments of major hospitals in Guangzhou, and doctors diagnosed him with “occult spermatozoa”, and finally he chose to successfully get his lover pregnant through IVF at our fertility center. So the reader can’t help but ask, “What is occult spermatozoa?” Definition of occult spermatozoa Spermatozoa are not found on semen smear or computer-assisted sperm analysis (CASA); however, spermatozoa can be found in the centrifugal sediment after the semen is centrifuged. It is an extremely severe form of oligospermia, which often manifests as sometimes sperm can be found and sometimes sperm cannot be found. Causes of cryptospermia Cryptospermia is mainly caused by various causes of poor testicular spermatogenesis. Common causes include karyotypic abnormalities or genetic deletions (Klinefelter’s syndrome, Y chromosome microdeletion), endocrine abnormalities (hypogonadotropic hypogonadism), testicular hypoplasia (cryptorchidism), inflammatory diseases of the reproductive system (orchitis, epididymitis, seminal vesiculitis), mumps, severe varicocele, tumors of the post-radiotherapy, taking drugs that inhibit spermatogenesis, bad habits (long-term night work and staying up late, smoking, alcoholism, drug abuse) and harmful working environment (high temperature, high radiation, exposure to toxic chemicals), etc. Treatment of occult spermatozoa Only a very small number of patients with occult spermatozoa can transform into oligospermia or normalize their sperm count after treatment, and can conceive naturally or undergo artificial insemination. The vast majority of patients with occult spermatozoa still need to use IVF technology to obtain a child. Treatment of cryptospermia should start with the cessation of the above-mentioned bad habits or removal from the harmful working environment; followed by spermopoietic medication and treatment for the cause of the disease. After the improvement and stabilization of the spermatogenic function after treatment (as evidenced by the finding of motile sperm in the semen centrifugal sediment for more than 2 consecutive times), the patient can be prepared for second-generation IVF (intracytoplasmic single sperm injection, ICSI). If it is caused by a karyotype or genetic abnormality, third generation IVF (preimplantation genetic diagnosis, PGD) needs to be considered.