 It is most commonly caused by congenital abnormalities, including imperforate hymen, transverse vaginal septum or vaginal hypoplasia.Other causes are acquired, such as cervical stenosis, intrauterine adhesions, endometrial cancer, and cervical cancer.Additionally, hematometra may develop as a complication of uterine or cervical surgery such as endometrial ablation, where scar tissue in the endometrium can "wall off" sections of endometrial glands and stroma causing blood to accumulate in the uterine cavity.