AUB
Could you clarify what you mean by "AUB"? It could refer to a few different things:
- American University of Beirut - the Lebanese university
- Abnormal Uterine Bleeding - a medical/gynecological term
- Something else entirely
What are you looking for?
Second
Reading File
Asking for Preferences
Finding Sources
Searching PubMed
"abnormal uterine bleeding" AND management
Reading File
Reading File
Reading File
Reading File
Finding Sources
Reading File
Reading File
Reading File
I now have enough comprehensive content from multiple authoritative sources to write a thorough overview. Let me compile this.
Abnormal Uterine Bleeding (AUB)
Definition & Normal Menstrual Parameters
AUB is defined as any bleeding from the uterus that falls outside the normal pattern. For reference:
- Normal cycle interval: 24-38 days
- Normal duration of flow: 4-8 days
- Normal blood loss: ~35 mL; >80 mL is abnormal
- Bleeding beyond 7 days is considered abnormal
The older terms "menorrhagia," "menometrorrhagia," and "dysfunctional uterine bleeding" have been retired in favour of the PALM-COEIN classification.
The PALM-COEIN Classification (FIGO 2011)
Established by the FIGO Working Group on Menstrual Disorders, this system divides causes into structural and non-structural categories:
| Category | Acronym | Causes |
|---|---|---|
| Structural | PALM | Polyp, Adenomyosis, Leiomyoma, Malignancy & hyperplasia |
| Non-structural | COEIN | Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not otherwise classified |
The PALM conditions are diagnosed via imaging or histology; COEIN conditions are medical/non-structural diagnoses.
Epidemiology
- Affects 10-30% of women of reproductive age
- ~20% of cases are postmenarchal (adolescent) bleeding - due to immaturity of the hypothalamic-pituitary-ovarian (HPO) axis causing anovulation
- ~50% are perimenopausal - related to incipient ovarian failure
- 75% of cases have no demonstrable organic cause - termed anovulatory (dysfunctional) bleeding
- Black women have a 2-3x higher rate of fibroid-related AUB
- Postmenopausal bleeding must be considered endometrial cancer until proven otherwise
Pathophysiology by Cause
Anovulatory Bleeding (Most Common)
Without ovulation, no corpus luteum forms and no progesterone is produced. Unopposed estrogen causes the endometrium to proliferate excessively, become unstable, and shed irregularly - resulting in unpredictable heavy or irregular bleeding.
Leiomyomas (Fibroids)
Submucosal fibroids project into the uterine cavity, increasing endometrial surface area and preventing adequate uterine contraction over endometrial vessels. They are most common at ages 45-49 and disproportionately affect Black women.
Coagulopathy
Most commonly von Willebrand disease and idiopathic thrombocytopenic purpura (ITP). Screen if: heavy bleeding since menarche, family history of coagulopathy, concurrent medications, or signs of bleeding elsewhere (easy bruising, epistaxis).
Iatrogenic
Oral contraceptives, IUCDs, hormonal contraceptives, anticoagulants. Tamoxifen (used in breast cancer) induces uterine abnormalities (polyps, hyperplasia, cancer) in 10-40% of women.
Types of Abnormal Bleeding
| Pattern | Description |
|---|---|
| Menstrual (heavy) | At time of expected period |
| Intermenstrual | Between periods |
| Postcoital | After intercourse (think cervical pathology) |
| Postmenopausal | After 12 months without a period - always abnormal |
| Post-instrumentation | After IUCD insertion, curettage |
Diagnosis & Workup
History
- Amount, duration, and pattern of blood loss
- Prospective charting of bleeding days
- Always exclude pregnancy and bleeding diathesis
Physical Examination
- Pelvic exam: assess tenderness, mass, uterine enlargement
- Papanicolaou smear (cervical screening)
- Signs of anaemia in severe cases
Laboratory Tests
- Complete blood count + platelet count
- Coagulation studies (including von Willebrand factor screening)
- Thyroid function tests (hypo/hyperthyroidism can cause AUB)
- Fasting blood glucose
- Pregnancy test (beta-hCG)
- Prolactin level
- STI screening
Imaging
- Pelvic ultrasound (2D/3D, or saline sonogram) - first-line for structural evaluation
- Adenomyosis on USS: anechogenic myometrial cysts with acoustic shadowing (fan-shaped)
Endometrial Biopsy (Pipelle or hysteroscopy-guided)
Indicated in:
- All women >45 years with AUB
- Women <45 with risk factors: obesity, unopposed oestrogen, persistent or refractory AUB, strong family history of cancer
- Persistent intermenstrual bleeding
- Endometrial thickness >4 mm in postmenopausal women on USS, or >7 mm in women with PCOS
- Suspected endometrial pathology
Hysteroscopy combined with biopsy improves sensitivity and specificity over either alone.
Treatment
Medical Management (First Line)
| Scenario | Treatment |
|---|---|
| Acute profuse anovulatory bleeding | Combined OCP every 6 hours x 5-7 days (off-label); bleeding should stop within 24 hours |
| Acute - IV route needed | Conjugated oestrogens 25 mg IV every 4 hours (up to 3 doses) + simultaneous medroxyprogesterone acetate 5-10 mg orally x 10 days |
| Ongoing anovulatory bleeding (non-acute) | Cyclic combined OCP or progestin (medroxyprogesterone acetate, norethindrone 5 mg daily) |
| Ovulatory AUB (heavy regular periods) | NSAIDs, tranexamic acid, combined OCP, or levonorgestrel IUD |
| Uterine fibroids (medical) | Elagolix 300 mg twice daily or relugolix 40 mg daily; or uterine artery embolization |
| Pregnancy desired | Induce ovulation |
After acute IV oestrogen therapy, expect heavy withdrawal bleeding 2-4 days after stopping; follow with cyclic OCP for at least 3 cycles.
Surgical / Interventional Options
| Procedure | Indication |
|---|---|
| Endometrial ablation | Persistent bleeding refractory to medical therapy (not 100% effective; ~29% require hysterectomy within 5 years) |
| Uterine artery embolization | Symptomatic fibroids (note: ~31% ultimately require hysterectomy) |
| Hysteroscopic polypectomy | Endometrial/endocervical polyps |
| Myomectomy | Fibroids (fertility-preserving) |
| Hysterectomy | Refractory symptoms, malignancy on biopsy, failure of all other options |
Dilation and curettage alone is not an effective means of controlling bleeding and is not required before hysterectomy.
Special Populations
Postmenopausal Women
Postmenopausal bleeding is not classified under PALM-COEIN - it is its own diagnosis. The most common cause is endometrial atrophy, but endometrial carcinoma must always be excluded. All cases require thorough evaluation.
Adolescents
Anovulatory cycles from HPO axis immaturity. Coagulation disorders (especially von Willebrand disease) are proportionally more common in this age group.
Women on Tamoxifen
Aromatase inhibitors (anastrozole, letrozole, exemestane) cause far less endometrial pathology than tamoxifen and may reverse tamoxifen-induced abnormalities.
Recent Evidence
A 2025 meta-analysis (PMID 39617186) on etiology and diagnosis of heavy menstrual bleeding found that coagulation disorders are more prevalent than historically recognised, reinforcing the importance of systematic coagulopathy screening. A 2026 meta-analysis (PMID 41791665) confirmed a significant rate of AUB in women on anticoagulation for venous thromboembolism - an important iatrogenic category to consider.
Sources: Goldman-Cecil Medicine, Sabiston Textbook of Surgery, Berek & Novak's Gynecology, Rosen's Emergency Medicine, Bailey & Love's Surgery, Tintinalli's Emergency Medicine.
This is a shared conversation. Sign in to Orris to start your own chat.