Abnormal uterine bleeding

Abnormal uterine bleeding is vaginal bleeding from the uterus that is abnormally frequent, lasts excessively long, is heavier than normal, or is irregular.<ref name="ACOG2017">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name="Bac2017">Template:Cite journal</ref> The term "dysfunctional uterine bleeding" was used when no underlying cause was present.<ref name="Bac2017" /> Quality of life may be negatively affected.<ref name="Whit2016" />

The underlying causes may be structural or non-structural and are classified in accordance with the FIGO system 1 & 2.<ref name="Bac20172">Template:Cite journal</ref><ref name="Jain_2023">Template:Cite journal</ref> Common causes include: Ovulation problems, fibroids, the lining of the uterus growing into the uterine wall, uterine polyps, underlying bleeding problems, side effects from birth control, or cancer.<ref name="Bac20172" /> 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.<ref name="Bac20172" /> The first step in work-up is to rule out a tumor or pregnancy.<ref name="Bac20172" /><ref name="Che20172">Template:Cite journal</ref> Vaginal bleeding during pregnancy may be abnormal in certain circumstances. Please see Obstetrical bleeding and early pregnancy bleeding for more information.Medical imaging or hysteroscopy may help with the diagnosis.<ref name="Whit20162">Template:Cite journal</ref>

Treatment depends on the underlying cause.<ref name=Bac2017/><ref name=Whit2016/> Options may include hormonal birth control, gonadotropin-releasing hormone agonists, tranexamic acid, nonsteroidal anti-inflammatory drugs, and surgery such as endometrial ablation or hysterectomy.<ref name=ACOG2017/><ref name=Che2017>Template:Cite journal</ref> Over the course of a year, roughly 20% of reproductive-aged women self-report at least one symptom of abnormal uterine bleeding.<ref name=Whit2016>Template:Cite journal</ref>

Signs and symptoms

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 the International Federation of Gynecology and Obstetrics to standardize the differences between normal uterine bleeding and abnormal uterine bleeding based on frequency, duration, regularity and individual flow volume.<ref name="Jain_2023" /><ref name="Munro_2011">Template:Cite journal</ref>

Normal uterine bleeding

• Monthly Menstrual cycle occurring every 21 – 35 days. (Most common cause of uterine bleeding).<ref name="American College of Obstetricians and Gynecologists (ACOG)">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

• Neonatal uterine bleeding can occur in newborn females due to rapidly decreasing estrogen levels.<ref>Template:Cite journal</ref>
• Postpartum lochia is a bloody discharge that occurs post pregnancy and can last for several weeks.<ref>Template:Cite journal</ref>
• Uterine procedures such as biopsies, myomectomies, intrauterine device insertion and Pap smears can cause light bleeding that may last for several days.

Abnormal uterine bleeding

<ref name="American College of Obstetricians and Gynecologists (ACOG)" /><ref name="Bradley_2016">Template:Cite journal</ref><ref name="Wouk_2019">Template:Cite journal</ref><ref name="Jain_2023"/>

• Menstrual bleeding starts before 21 days or after 35 days
• Menstrual bleeding that lasts more than 7 days
• Heavy menstrual cycle bleeding that necessitates changing pad or tampon roughly every hour (about 80 mL of blood loss) .
• Any bleeding between menstrual cycles, after sexual intercourse or bleeding after six months of menopause
• Premenopausal menstrual bleeding that stops for more than 3 months

Causes and mechanisms

The causes of abnormal uterine bleeding are divided into nine categories (PALM COEIN) under the FIGO System 2 which is the second part of the classification system developed by the International Federation of Gynecology and Obstetrics. More than one category of causes may apply in an individual case.<ref name="Jain_2023" /><ref name="Munro_2011" />

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.<ref name="Committee on Practice Bulletins—Gynecology_2012">Template:Cite journal</ref><ref>Template:Cite journal</ref>

Premenopausal group includes all persons with a uterus that have started and are currently experiencing menstruation.

• Adolescents between the ages of 13 and 19 commonly experience irregular menstrual cycles as their hormones and ovulation cycle regulates. Birth control, coagulopathies, pregnancy, abnormal uterine lining growths and infection are also common causes of abnormal bleeding in this age range.
• Adults between the ages of 20 and 40 most commonly experience abnormal uterine bleeding due to pregnancy and hormonal birth control. Uterine structural abnormalities (See PALM in chart below) ovulatory and endometrial dysregulation are also common causes. Uterine cancer is a rare cause of abnormal uterine bleeding in this group.<ref name="Jain_2023" /><ref name="Wouk_2019" /><ref name="Committee on Practice Bulletins—Gynecology_2012" />

Postmenopausal group includes all persons with a uterus that have stopped 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.<ref>Template:Cite journal</ref><ref name="Committee on Practice Bulletins—Gynecology_2012" />

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.<ref name="Jain_2023" /><ref name="Munro_2011" /><ref name="Bradley_2016" /><ref name="Whitaker_2016" /><ref name="Leal_2024" />

For more in-depth information about each of these causes, click on the links in the table below.

FIGO System 2 "PALM COEIN " Classifications

	Structural Causes	Description	How this Leads to Abnormal Bleeding
P	Polyps	Condensed tissue overgrowths along the endometrial lining <ref name="Jain_2023" /><ref name="Leal_2024" /><ref name="Marnach_2019" />	Possibly due to stromal cell congestion that blocks normal blood flow leading to expulsion of excess blood through the uterus. <ref name="Jain_2023" /><ref name="Marnach_2019">Template:Cite journal</ref><ref name="Leal_2024">Template:Cite journal</ref>
A	Adenomyosis	Endometrial tissue invades the uterine muscle causing enlargement <ref name="Leal_2024" /><ref name="Marnach_2019" /><ref name="Khan_2022" />	Possibly due to reduction of hormone signaling in response to fibrotic lesions that invade the uterine muscle and cell wall lining meet.<ref name="Leal_2024" /><ref name="Khan_2022">Template:Cite journal</ref> Increased angiogenesis and immunological oxidative stress have also been implicated.<ref>Template:Cite journal</ref><ref name="Marnach_2019" />
L	Leiomyoma (Fibroids)	Non-cancerous smooth muscle cell tumors <ref name="Jain_2023" /><ref name="Whitaker_2016" /><ref name="Leal_2024" />	Possibly due to increased vasculature (blood vessels) and surface area of uterine lining. Impaired angiogenesis and uterine blood clotting abilities may also contribute.<ref name="Whitaker_2016">Template:Cite journal</ref><ref name="Leal_2024" /><ref name="Jain_2023" />
M	Malignancy (Cancer)	Uterine cancer & Endometrial hyperplasia <ref name="Wouk_2019" /><ref name="Whitaker_2016" /><ref name="Marnach_2019" />	Most likely due to long-term exposure to estrogen without simultaneous exposure to progesterone.<ref name="Wouk_2019" /><ref name="Whitaker_2016" /><ref name="Marnach_2019" />
	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.<ref name="Whitaker_2016" /><ref name="Marnach_2019" />	Improper platelet function and blood clotting factor deficiencies impair uterine ability to create blood clots that prevent excess bleeding.<ref name="Marnach_2019" /><ref name="Whitaker_2016" />
O	Ovulatory Disorders	Conditions impairing the female body's ability to produce gametes (reproductive eggs). <ref name="Jain_2023" /><ref name="Munro_2022" />	Possibly due to abnormal increases or decreases of reproductive hormones interrupt the ovulation cycle and prevent appropriate shedding and regeneration of the uterine lining.<ref name="Munro_2022">Template:Cite journal</ref><ref name="Jain_2023" />
E	Endometrial Disorders	Impairment in function of cells that line the uterus that results in excessive bleeding. <ref name="Jain_2023" /><ref name="Wouk_2019" /><ref name="Marnach_2019" />	Possibly due to vasoconstriction impairment, systemic inflammation or infections.<ref name="Jain_2023" /><ref name="Wouk_2019" /><ref name="Marnach_2019" />
I	Iatrogenic (Medical Errors)	Bleeding caused by medications or medical procedures. Hormone therapy (contraceptive and non contraceptive) is the most common cause. <ref name="Wouk_2019" /><ref name="Leal_2024" /><ref name="Marnach_2019" />	Medications and IUD insertions can possibly cause disruption in hormonal regulation of cell wall repair, inflammatory response and blood vessel system of the endometrium. <ref name="Wouk_2019" /><ref name="Leal_2024" /><ref name="Marnach_2019" />
N	Not Otherwise Classified	Rare impairments such as arteriovenous malformations, endometrial pseudoaneurysms (due to postpartum caesarean scar), myometrial hypertrophy and chronic endometritis. <ref name="Jain_2023" /><ref name="Whitaker_2016" /><ref name="Marnach_2019" />	Irregular connections between arteries and veins in uterus lead to excess bleeding. Pocket of blood can form within uterine scar tissue post C-section.<ref name="Jain_2023" /><ref name="Marnach_2019" /><ref name="Whitaker_2016" />

Diagnosis

Diagnosis of abnormal uterine bleeding starts with a medical history and physical examination.<ref name=Whit2016/> 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 as herbal supplements, hormonal contraceptives, over-the-counter drugs such as aspirin, or blood thinners.<ref name=AUB2019/>

Medical tests include a blood test, to see whether the abnormal bleeding has caused anemia, and a pelvic ultrasound, to see whether the abnormal bleeding is caused by a structural problem, such as a uterine fibroid.<ref name="Whit2016" /> Ultrasound is specifically recommended in those over the age of 35 or those in whom bleeding continues despite initial treatment.<ref name="Mer2018Pro" /> Laboratory assessment of thyroid stimulating hormone (TSH), pregnancy, and chlamydia is also recommended.<ref name="AUB2019" />

More extensive testing might include magnetic resonance imaging and endometrial sampling.<ref name=Whit2016/> Endometrial sampling is recommended in those over the age of 45 who do not improve with treatment and in those with intermenstrual bleeding that persists.<ref name=Whit2016/> The PALM-COEIN system may be used to classify the uterine bleeding.<ref name=AUB2019/>

Management

Treatment depends on the underlying cause.<ref name=Bac2017/><ref name=Whit2016/> Options may include hormonal birth control, gonadotropin-releasing hormone (GnRH) agonists, tranexamic acid, nonsteroidal anti-inflammatory drugs, and surgery such as endometrial ablation or hysterectomy.<ref name=ACOG2017/><ref name=Che2017/> Polyps, adenomyosis, and cancer are generally treated by surgery.<ref name=Whit2016/> Iron supplementation may be needed.<ref name=Whit2016/>

Terminology

The terminology "dysfunctional uterine bleeding" is no longer recommended.<ref name=Bac2017/> Historically dysfunctional uterine bleeding meant there was no structural or systemic problems present.<ref name=Bac2017/> In abnormal uterine bleeding underlying causes may be present.<ref name=Bac2017/>

Epidemiology

About one-third of all medical appointments with gynecologists involve abnormal uterine bleeding, with the proportion rising to 70% in the years around menopause.<ref name=AUB2019>Template:Cite journal</ref>

External links

• Merck Manual Abnormal Uterine Bleeding