PIP: Abnormal uterine bleeding is the most common complication of IUD use. Minor metrorrhagia during the insertion and the initial 2 or 3 cycles is common and has no pathological significance. The true complications are menorrhagia, or augmentation of the volume of blood, and metrorrhagia, or repeated intermenstrual bleeding. Inert IUDs increase the volume of menstrual blood loss by 100-140% and copper devices by 50-60%. Blood loss is directly related to the size and form of the IUD; copper devices cause less bleeding primarily because of their reduced surface area. Anemia secondary to menstrual problems is a serious problem in developing countries. Metrorrhagia in IUD users is often associated with pain and may lead to removal of the device. It may result from the same array of morphological and functional modifications of the endometrium as menorrhagia, but more often it signals a true complication, either utero-adnexal infection, an intra- or extrauterine pregnancy or spontaneous abortion, or an inadaptation to the uterine cavity or a displacement of the IUD, perhaps with perforation. Metrorrhagia may also result from appearance of a calcium deposit on the surface of an IUD in place for over 2 years, or it may reveal a pathology unrelated to the IUD, such as a myoma, polyp, endometrial hyperplasia, or adenomyosis. Menorrhagia is an almost inevitable consequence of IUD use, but metrorrhagia requires close surveillance. A clinical examination aided by diagnostic tests is needed to distinguish between complications requiring immediate treatment and simple intolerances that may spontaneously resolve. Sonography is indispensable, to confirm good placement of the IUD or to rule out uterine anomalies or pregnancy. Hysteroscopy can be performed with the IUD in place or not, to diagnose localized endometrial hyperplasias, polyps, poorly positioned IUDs, or partial or complete perforations. Hysterography after infection and pregnancy have been ruled out can reveal endocavity pathology, uterine malformation, poorly positioned IUD, or possible perforation, but many practitioners prefer hysteroscopy. In most cases, spotting and menorrhagia result from inflammatory responses of the endometrium to the foreign body represented by the IUD. Antifibrinolytics, vascular protectors, or perhaps progestins such as lynestrenol may be used to reduce bleeding. Prostaglandin inhibitors may be used only during menstruation. A progesterone-releasing IUD ma reduce menstrual volume by 40-50%, sometimes at the cost of several months of amenorrhea, but the total number of days of bleeding may be increased. If there is no improvement with these measures, the IUD should be removed and systematically cultured. A difficult removal may signal perforation, in which case the device should be laparoscopically removed.