Contents
Broad term that describes irregularities in the menstrual cycle involving frequency, regularity, duration, and volume of flow outside of pregnancy.
- Affects 14–25% of women of reproductive age
Clinical definitions:
Abnormal uterine bleeding (AUB) describes a range of symptoms, such as heavy menstrual bleeding (HMB, bleeding above the 95th centile of the normal population), inter-menstrual bleeding and a combination of both heavy and prolonged menstrual bleeding.
Heavy menstrual bleeding (HMB) is the most common clinical presentation of AUB. Formerly called “dysfunctional uterine bleeding”, refers to AUB which is not caused by structural lesions of the uterus
Etiology
PALM-COEIN:
Acronym by International Federation of Obstetrics and Gynecology (FIGO) to classify the underlying etiologies of abnormal uterine bleeding.
Extremes of reproductive years:
- First 2 years after onset of menstruation
- Immaturity of HPA-Axis → Anovulation
- Perimenopausal period
- Non-response to hormones → Anovulation
- Follicular dysfunction → Oestrogen fails to stimulate FSH → Late cycle oestrogen breakthrough bleeding
Pathophysiology
Menstrual cycle:
The uterine and ovarian arteries supply blood to the uterus. These arteries become the arcuate arteries; then the arcuate arteries send off radial branches which supply blood to the 2 layers of the endometrium, the functionalis, and basalis layers. Progesterone levels fall at the end of the menstrual cycle, leading to enzyme breakdown of the functionalis layer of the endometrium. This breakdown leads to blood loss and sloughing which makes up menstruation.
Functioning platelets and thrombin, and vasoconstriction of the arteries to the endometrium control blood loss. Any derangement in the structure of the uterus (such as leiomyoma, polyps, adenomyosis, malignancy or hyperplasia), derangements to the clotting pathways (coagulopathies or iatrogenically), or disruption of the hypothalamic-pituitary-ovarian axis (through ovulatory/endocrine disorders or iatrogenically) can affect menstruation and lead to abnormal uterine bleeding.
Anovulatory cycles (80% cases)
Corpus luteal failure
↓
Progesterone deficiency
↓
Oestrogen stimulation
↓
Endometrium proliferation
↓
Outgrows its blood supply
↓
Irregular sloughing off
+
Bleeding
Ovulatory cycles (20% cases):
Luteal phase deficiency
↓
↓ Progesterone
↓
Irregular sloughing off
+
Bleeding
- Death due to:
- Anaemia
- Hemorrhagic shock
Diagnosis
As part of structured history, factors such as co-morbidities, polypharmacy, body mass index (BMI), previous surgery and most crucially fertility desire and impact of pressure symptoms must be assessed as these significantly affect treatment approach.
- TV-USG remains the most acceptable and validated first-line investigation.
Differential diagnosis:
Management
Management of AUB-L should address fertility desire, impact of pressure symptoms, co-morbidities, and any other AUB contributors. Treatment should be individualised.
Immediate management:
- Hormonal methods (first-line management):
- Intravenous (IV) conjugated equine estrogen
- Combined oral contraceptive pills (OCPs)
- Oral progestins
- Tranexamic acid: Prevents fibrin degradation and can be used to treated acute AUB
- Tamponade with a Foley bulb is a mechanical option for treatment of acute AUB.
- IV fluids and blood products
- Desmopressin (intranasal/SC/EV): Acute AUB secondary to the coagulopathy von Willebrand disease.
Specific management:
- Polyp: Resection
- Adenomyosis: Surgery: hysterectomy; adenomyomectomy (not frequently performed)
- Malignancy:
- Surgery +/− adjuvant treatment
- High-dose progestogens (if surgery not possible)
- Palliation (including radiotherapy)
- Coagulopathy:
- Tranexamic acid
- Desmopressin (DDVAP)
- Ovulation:
- Lifestyle modification
- Cabergoline (if hyperprolactinaemia)
- Levothyroxine (if hypothyroid)
- Endometrial: Specific therapies await further delineation of underlying mechanisms
- Not otherwise classified:
- Antibiotics for endometritis
- Embolisation of AV malformation
Summary