Teratoma is not a twin. Teratoma, also known as ovarian dermatoid cyst, is a tumor of the ovary, which is divided into benign teratoma and malignant teratoma, which is not associated with female pregnancy. Teratoma is a tumor in the germ cells of the ovary, which is caused by the abnormal differentiation of the germ cells during the embryonic period. Typical symptoms caused by teratoma are abdominal mass, abdominal pain, bloating and dysmenorrhea. Twins, on the other hand, are categorized into identical and fraternal twins, which first of all the woman belongs to the state of pregnancy, with menopause, nausea, vomiting and other reactions. Blood sampling can detect increased human chorionic gonadotropin and a positive result on early pregnancy test paper. Teratoma is suspected and should be seen as soon as possible.