<unk>  develops when the uterus becomes distended with blood secondary to obstruction or atresia of the lower reproductive tract—the uterus, cervix or vagina—which would otherwise provide an outflow for menstrual blood. 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,<unk>  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. It can also develop after abortion, as well as after childbirth. It can also develop after female genital mutilation.
Hematometra
Pyometra
Hydrocolpos
Pelvic lipomatosis
Hydrosalpinx
Spermatocele
Endometriosis
Hematosalpinx