Dysfunctional uterine bleeding
|Dysfunctional uterine bleeding|
|Classification and external resources|
Dysfunctional Uterine Bleeding (DUB) is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic pathology. It is usually due to hormonal disturbances: reduced levels of progesterone causes low levels of prostaglandin F2alpha and causes menorrhagia; increased levels of tissue plasminogen activator (TPA) (a fibrinolytic enzyme) leads to more fibrinolysis.
Diagnosis must be made by exclusion, since organic pathology must first be ruled out.
It can be classified as ovulatory or anovulatory, depending on whether ovulation is occurring or not.
Some sources state that the term implies a hormonal mechanism.
10% of cases occur in women who are ovulating, but progesterone secretion is prolonged because estrogen levels are low. This causes irregular shedding of the uterine lining and break-through bleeding. Some evidence has associated Ovulatory DUB with more fragile blood vessels in the uterus.
It may represent a possible endocrine dysfunction, resulting in menorrhagia or metrorrhagia. Mid-cycle bleeding may indicate a transient estrogen decline, while late-cycle bleeding may indicate progesterone deficiency.
About 90% of DUB events occur when ovulation is not occurring (Anovulatory DUB). Anovulatory menstrual cycles are common at the extremes of reproductive age, such as early puberty and perimenopause (period around menopause). In such cases, women do not properly develop and release a mature egg. When this happens, the corpus luteum, which is a mound of tissue that produces progesterone, does not form. As a result, estrogen is produced continuously, causing an overgrowth of the uterus lining. The period is delayed in such cases, and when it occurs menstruation can be very heavy and prolonged. Sometimes anovulatory DUB is due to a delay in the full maturation of the reproductive system in teenagers. Usually, however, the mechanisms are unknown.
Assessment of anovulatory DUB should always start with a good medical history and physical examination. Laboratory assessment of hemoglobin, luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, T4, thyroid stimulating hormone (TSH), pregnancy (by βhCG), and androgen profile should also happen. More extensive testing might include an ultrasound and endometrial sampling.
Drug of choice is progesterone. Management of dysfunctional uterine bleeding predominantly consists of reassurance, though mid-cycle estrogen and late-cycle progestin can be used for mid- and late-cycle bleeding respectively.
Also, non-specific hormonal therapy such as combined high-dose estrogen and high-dose progestin can be given. Ormeloxifene is a non-hormonal medication that treats DUB but is only legally available in India.
- Bravender T, Emans SJ (June 1999). "Menstrual disorders. Dysfunctional uterine bleeding". Pediatr. Clin. North Am. 46 (3): 545–53, viii. PMID 10384806.
- "Dysfunctional Uterine Bleeding". Retrieved 2010-01-23.
- Bourdrez P, Bongers MY, Mol BW (July 2004). "Treatment of dysfunctional uterine bleeding: patient preferences for endometrial ablation, a levonorgestrel-releasing intrauterine device, or hysterectomy". Fertil. Steril. 82 (1): 160–6, quiz 265. doi:10.1016/j.fertnstert.2003.12.025. PMID 15237006.