Endometriosis is a common gynecological condition, which involves the implantation of endometrial tissue outside the uterine cavity. Endometriosis is a common cause of infertility: Firstly, when endometriosis occurs, it often affects the function of the ovaries. For example, ovarian chocolate cysts can affect the release of endocrine hormones in the ovaries, as well as cause ovarian ovulation disorders or premature ovarian failure. Secondly, endometriosis can cause inflammation in the pelvic cavity and adhesions within the pelvis. This will impact the function of the fallopian tubes, causing ovulation disorders in the tubes, as well as disorders in the transport function of the tubes. This can prevent fertilization, or after the sperm and egg have combined, the fallopian tubes may not be able to transport the fertilized egg to the uterine cavity, thus increasing the risk of ectopic pregnancy.