Testicular malformation is a male congenital developmental disorder or acquired testicular lesion caused by many factors, which can lead to infertility. Abnormal number of testicles, including azoospermia, single testicle and multiple testicles. Testicular size is abnormal, underdeveloped and smaller than normal people, which are mostly non-isolated symptoms. Testicles are enlarged due to hyperplasia, such as testicular teratoma and congenital atrophy. Testicular fusion. Refers to the integration of bilateral testicles in the abdominal cavity or scrotum, which is easily mistaken for cryptorchidism or monogamy. Most of them are complicated with renal malformation. Abnormal attachment of testis and epididymis can make sperm pass through and cause infertility. If the two are not connected well, it is easy to have testicular torsion and even tissue necrosis due to insufficient blood supply.