The term abnormal uterine bleeding (AUB), formerly known as dysfunctional uterine bleeding (DUB), is not a definite diagnosis of a disease but rather a disease of exclusion for other diseases. It encompasses a variety of conditions that alter or change the normal menstrual flow or rhythm of the patient.
AUB represents a variety of abnormalities of menstruation which may or may not be due to an underlying disease or pathological process. It is a common gynaecological problem in the female population as most women present to the clinics with this complain of abnormal menstrual flow or rhythm.
Majority of cases resolve spontaneously or are not severe enough to warrant any specific therapy. AUB affects women with the highest occurrence during the active reproductive ages between 20years – 40years and perimenaupausal years of 40 and above. The lowest incidence is recorded in women below the age of 20.
TYPES OF ABNORMAL UTERINE BLEEDING
AUB is broadly categorised into two types: Ovulatory AUB and Anovulatory AUB.
Ovulatory AUB covers about 10% of all cases and occurs in women whom ovulation is continuous. This continuous ovulation is due to prolonged progesterone secretion which causes irregular shedding of endometrium.
Anovulatory AUB is the most common type with over 90% of all cases and occurs in the absence of ovulation. Here the woman does not properly develop and release mature egg, hence, corpus luteum which produces progesterone does not form and as a result, estrogen is continuously released which causes an overgrowth of uterine lining. This makes menstruation heavy and prolonged.
Based on the aetiology (cause) and risk factors, AUB has been classified into three (3) :
- Primary AUB : this arise from factors which come from within the genital tract and reproductive system including the pituitary, hypothalamus and higher centres.
- Secondary AUB : this is when there is no detectable disease of the genital tract but there is a known disorder outside the genital tract which is responsible for the abnormal bleeding like myxedema, leukaemia, thrombocytopenic outputs e.t.c.
- Iatrogenic AUB : this is when the bleeding is associated with a therapeutic agent like some contraceptives especially IUCDs and injectable contraception of progesterone or estrogen.
CAUSES OF ABNORMAL UTERINE BLEEDING
- General systemic disease : a general debilitating disease or long standing illness resulting in malnutrition, excessive weight loss and anaemia tends to affect menstruation by causing decrease or cessation of menstrual flow. Acute febrile illness such as malaria and sudden shock can cause sudden onset of menstruation prematurely or varying amounts of bleeding.
- Endocrine disorders : like hypothyroidism and myxedema can cause menorrhagia or polymenorrhea. Liver disease such as cirrhosis or hepatitis may result in disturbance of normal metabolism and imagination of estrogen causing menorrhagia.
- Blood disorders : affecting coagulation cascade or increasing capillary fragility such as thrombocytopenic purpura, leukaemia, aplastic anaemia and Christmas disease may cause AUB.
- Endometriosis : adenomyosis, also called endometriosis interna causes menorrhagia whiles ovarian endometriosis may cause polymenorrhea and polymenorrhagia.
- Abnormalities of pregnancy : complications of pregnancy such as abortion, hydatidiform mole (molar pregnancy), and ectopic pregnancy can cause AUB.
- Infections : early or late onset of heavy and prolonged periods usually occurs in pelvic infections. Oligomenorrhea or amenorrhea is common in genital tuberculosis.
- Tumours : benign and malignant tumours of the genital tract involving the uterus, cervix or ovaries may cause AUB. Estrogen producing tumours causes cyclical anovulatory bleeding.
- Iatrogenic causes from the use of other therapeutic agents like contraceptives.
CLINICAL DIAGNOSIS OF ABNORMAL UTERINE BLEEDING
- A very comprehensive history taking of medical and menstrual history is very important to ascertain cause of irregular bleeding.
- Detailed physical examination which include abdominal and pelvic examinations for masses, polyps and vaginal wall e.t.c
- Laboratory investigations including HCG levels to rule out pregnancy, full blood count, malaria tests, PAP smear, endometrial biopsy, coagulation factors /studies, thyroid function test, adrenal function test, liver function test, and hormonal assays of serum GnRH, FSH, LH, prolactin etc.
- Imaging studies with ultrasound, hysteroscopy and laparoscopy.
MANAGEMENT OF ABNORMAL UTERINE BLEEDING
Many cases of AUB resolve spontaneously and treatment is given only where indicated based on the event findings and effect of bleeding on the patient. The aim of treatment is to arrest bleeding, replace lost iron and prevent anaemia.
- General measures include explaining the situation to the patient, reassuring them and giving haematonics.
- Conservative therapy to manage effects of bleeding involve the use of hormones (estrogen and progesterone oral contraceptive pills), prostaglandin synthethase inhibitors, NSAIDs, and antifibrinolytic agents.
- Radical therapy of AUB is through surgical hysterectomy, endometrial ablation or myomectomy (for fibroid causes).
Medscape : “Abnormal (dysfunctional) uterine bleeding ”
Wikipedia : “Dysfunctional uterine bleeding ”