| Abnormal uterine bleeding | |
|---|---|
| Other names | Atypical vaginal bleeding, dysfunctional uterine bleeding (DUB), abnormal vaginal bleeding |
| Specialty | Gynecology |
| Symptoms | Irregular, abnormally frequent, prolonged, or excessive amounts ofuterine bleeding[1] |
| Complications | Iron deficiency anemia[2] |
| Causes | Ovulation problems,fibroids,lining of the uterus growing into the uterine wall,uterine polyps, underlyingbleeding problems, side effects frombirth control,cancer[3] |
| Diagnostic method | Based on symptoms, blood work,medical imaging,hysteroscopy[2] |
| Differential diagnosis | Ectopic pregnancy[4] |
| Treatment | Hormonal birth control,GnRH agonists,tranexamic acid,NSAIDs, surgery[1][5] |
| Frequency | Relatively common[2] |
Abnormal uterine bleeding isvaginal bleeding from theuterus that is abnormally frequent, lasts excessively long, isheavier than normal, or is irregular.[1][3] The term "dysfunctional uterine bleeding" was used when no underlying cause was present.[3]Quality of life may be negatively affected.[2]
The underlying causes may be structural or non-structural and are classified in accordance with the FIGO system 1 & 2.[3][6] Common causes include:Ovulation problems,fibroids, thelining of the uterus growing into the uterine wall,uterine polyps, underlyingbleeding problems, side effects frombirth control, orcancer.[3] Susceptibility to each cause is often dependent on an individual's stage in life (prepubescent, premenopausal, postmenopausal). More than one category of causes may apply in an individual case.[3] The first step in work-up is to rule out atumor orpregnancy.[3][5] Vaginal bleeding during pregnancy may be abnormal in certain circumstances. Please seeObstetrical bleeding andearly pregnancy bleeding for more information.Medical imaging orhysteroscopy may help with the diagnosis.[2]
Treatment depends on the underlying cause.[3][2] Options may includehormonal birth control,gonadotropin-releasing hormone agonists,tranexamic acid,nonsteroidal anti-inflammatory drugs, and surgery such asendometrial ablation orhysterectomy.[1][5] Over the course of a year, roughly 20% of reproductive-aged women self-report at least one symptom of abnormal uterine bleeding.[2]
Although uterine bleeding can be alarming and abnormal, there are many instances in which uterine bleeding is normal.FIGO System 1 is the first part of the classification system developed by theInternational Federation of Gynecology and Obstetrics to standardize the differences between normal uterine bleeding and abnormal uterine bleeding based onfrequency, duration, regularity and individual flow volume.[6][7]
The causes of abnormal uterine bleeding are divided into nine categories (PALM COEIN) under theFIGO System 2 which is the second part of the classification system developed by theInternational Federation of Gynecology and Obstetrics. More than one category of causes may apply in an individual case.[6][7]
Causes of abnormal uterine bleeding can also be narrowed down according to age group because each stage of life brings unique changes to an individual's uterine structure and systemic hormones.
Prepubescent group includes all persons with a uterus that have not yet started menstruation (monthly bleeding). Newborn uterine bleeding is a normal occurrence and should gradually stop as estrogen leaves the infant's body. Any bleeding outside of the newborn period is abnormal and should be investigated for a cause, including sexual abuse.[13][14]
Premenopausal group includes all persons with a uterus that have started and are currently experiencing menstruation.
Postmenopausal group includes all persons with a uterus that havestopped menstruation for more than one year or 12 consecutive months. Declining ovulatory function or menopause, is the most common cause of abnormal bleeding. Menstrual bleeding becomes gradually less frequent and lighter until it completely stops. Uterine cell wall thinning and overgrowth as well as cancer are common causes for abnormal uterine bleeding concern.[15][13]
The mechanisms, or reasons, that each of the PALM COEIN abnormalities cause uterine bleeding is not well understood, but the table below includes some scientific hypothesis and observations that give a strong indication of what may be happening.[6][7][11][2][16]
For more in-depth information about each of these causes, click on the links in the table below.
| Structural Causes | Description | How this Leads to Abnormal Bleeding | |
|---|---|---|---|
| P | Polyps | Condensed tissue overgrowths along the endometrial lining[6][16][17] | Possibly due tostromal cell congestion that blocks normal blood flow leading to expulsion of excess blood through the uterus.[6][17][16] |
| A | Adenomyosis | Endometrial tissue invades the uterine muscle causing enlargement[16][17][18] | Possibly due to reduction of hormone signaling in response tofibrotic lesions that invade the uterine muscle and cell wall lining meet.[16][18] Increasedangiogenesis and immunologicaloxidative stress have also been implicated.[19][17] |
| L | Leiomyoma (Fibroids) | Non-cancerous smooth muscle cell tumors[6][2][16] | Possibly due to increased vasculature (blood vessels) and surface area of uterine lining. Impaired angiogenesis and uterine blood clotting abilities may also contribute.[2][16][6] |
| M | Malignancy (Cancer) | Uterine cancer & Endometrial hyperplasia[12][2][17] | Most likely due to long-term exposure to estrogen without simultaneous exposure to progesterone.[12][2][17] |
| Nonstructural Causes | Description of Cause | How this Leads to Abnormal Bleeding | |
| C | Coagulopathies (Clotting Disorders) | Bleeding disorders impairing the body's blood clotting function. Microbial infection, renal and liver disease, and cancer also contribute.[2][17] | Improper platelet function and blood clotting factor deficiencies impair uterine ability to create blood clots that prevent excess bleeding.[17][2] |
| O | Ovulatory Disorders | Conditions impairing the female body's ability to produce gametes (reproductive eggs).[6][20] | Possibly due to abnormal increases or decreases of reproductive hormones interrupt the ovulation cycle and prevent appropriate shedding and regeneration of the uterine lining.[20][6] |
| E | Endometrial Disorders | Impairment in function of cells that line the uterus that results in excessive bleeding.[6][12][17] | Possibly due to vasoconstriction impairment, systemic inflammation or infections.[6][12][17] |
| I | Iatrogenic (Medical Errors) | Bleeding caused by medications or medical procedures. Hormone therapy (contraceptive and non contraceptive) is the most common cause.[12][16][17] | Medications andIUD insertions can possibly cause disruption in hormonal regulation of cell wall repair,inflammatory response and blood vessel system of the endometrium.[12][16][17] |
| N | Not Otherwise Classified | Rare impairments such as arteriovenous malformations, endometrial pseudoaneurysms (due to postpartum caesarean scar), myometrial hypertrophy and chronic endometritis.[6][2][17] | Irregular connections between arteries and veins in uterus lead to excess bleeding. Pocket of blood can form within uterine scar tissue post C-section.[6][17][2] |
Diagnosis of abnormal uterine bleeding starts with amedical history andphysical examination.[2] Normal menstrual bleeding patterns vary from woman to woman, so the medical history covers specific details about the woman's individual menstrual bleeding pattern, such as its predictability, length, volume, and whether she experiences cramps or other pain. The healthcare provider will also check to see whether she or any family members have any potentially related health conditions, and whether she is taking medication that might increase or decrease menstrual bleeding, such asherbal supplements,hormonal contraceptives, over-the-counter drugs such asaspirin, orblood thinners.[21]
Medical tests include a blood test, to see whether the abnormal bleeding has causedanemia, and a pelvicultrasound, to see whether the abnormal bleeding is caused by a structural problem, such as auterine fibroid.[2] Ultrasound is specifically recommended in those over the age of 35 or those in whom bleeding continues despite initial treatment.[4] Laboratory assessment ofthyroid stimulating hormone (TSH),pregnancy, andchlamydia is also recommended.[21]
More extensive testing might includemagnetic resonance imaging andendometrial sampling.[2] Endometrial sampling is recommended in those over the age of 45 who do not improve with treatment and in those withintermenstrual bleeding that persists.[2] The PALM-COEIN system may be used toclassify the uterine bleeding.[21]
Treatment depends on the underlying cause.[3][2] Options may includehormonal birth control,gonadotropin-releasing hormone (GnRH) agonists,tranexamic acid,nonsteroidal anti-inflammatory drugs, and surgery such asendometrial ablation orhysterectomy.[1][5] Polyps, adenomyosis, and cancer are generally treated by surgery.[2]Iron supplementation may be needed.[2]
The terminology "dysfunctional uterine bleeding" is no longer recommended.[3] Historically dysfunctional uterine bleeding meant there was no structural or systemic problems present.[3] In abnormal uterine bleeding underlying causes may be present.[3]
About one-third of all medical appointments withgynecologists involve abnormal uterine bleeding, with the proportion rising to 70% in the years aroundmenopause.[21]