Adhesions inside the endometrial cavity caused by prior infection (endometritis), especially if there has been a curettage during the period of infection, or if curettage is performed in conditions of low estrogen. The circumstances in which this combination is most common are treatment for a missed abortion and treatment of a postpartum hemorrhage (bleeding a few weeks after the birth of a baby). A cause of absent periods amenorrhea, light periods (hypomenorrhea) or recurrent miscarriages.

Scar tissue, in particular between the serosa (surface lining) of abdominal or pelvic organs in the peritoneal cavity, which can interfere with the access the fallopian tube has to the ovary at ovulation. Adhesions can be thin and transparent (sometimes called filmy or Grade 1), a little like thin plastic wrap; thicker, and containing more scar tissue and blood vessels (Grade 2); or thick, dense and tough (Grade 3). Adhesions are caused by infections, endometriosis or a previous operation. Not all adhesions are important: it depends on where they are. See also intrauterine adhesions. The treatment of adhesions requires microsurgery, and there are special steps that have to be taken to stop them coming back again.

Absent menstrual periods, either because of absent ovulation (anovulation) or because of absence of, destruction of, or obstruction to the menstrual flow from the uterus, such as with intrauterine adhesions (when it's known as Asherman's syndrome).

The combination of intrauterine adhesions and amenorrhea.

An operation performed at hysteroscopy to treat menorrhagia by intentionally producing endometrial atrophy and intrauterine adhesions.

Light periods, particularly in a woman who has previously had much heavier periods. Occurs normally on the oral contraceptive (birth control) pill. Occurs abnormally with intrauterine adhesions or endometrial atrophy; see also Asherman's syndrome.

A miscarriage that should have happened but hasn't. As a result, the pregnancy tissue in the uterus gets tougher and more difficult to get out with a uterine curettage -- which is the only treatment for it, but risks producing intrauterine adhesions. The pregnancy test can stay positive for many weeks or even months.