Teratoma, under normal circumstances, does not affect menstruation, but it does affect fertility. If it is confirmed that one side has a teratoma, surgery is generally required. After treatment, the ovary on that side is typically removed. Once removed, that ovary will no longer ovulate, and ovulation must occur from the other ovary. The maintenance of hormone levels in the body needs to be supported by the other ovary. If the function of the other ovary is normal, menstruation will continue to occur normally; it will not affect menstruation. However, if after the removal of the teratoma, one ovary is removed, the chance of conception is reduced by half compared to others. Therefore, it is crucial for patients with teratoma to undergo surgery as early as possible. After the surgery, if the pathology shows no issues and if it is a simple teratoma removal, it does not affect menstruation.