Acute Abnormal Uterine Bleeding

Acute abnormal uterine bleeding is a sudden onset of abnormal bleeding from the uterus (heavy, prolonged or unscheduled) in a nonpregnant woman of reproductive age, seen within hours to days and assessed for urgency. Causes include anovulation, fibroids, adenomyosis, polyps, hormonal contraception, infection, coagulopathy, retained pregnancy tissue, endometrial hyperplasia or cancer and trauma. It matters because the first task is to separate the unstable woman who needs resuscitation from the stable woman who can be treated as an outpatient.

• Risk factors: adolescence, perimenopause, obesity, polycystic ovary syndrome, bleeding disorders, anticoagulants, contraception change, sexually transmitted infection.
• Pregnancy must be excluded before any other treatment.
• Most stable women recover with oral treatment at home.

Women have a sudden bleed that is heavier or longer than usual, or unexpected spotting, with or without pain, discharge or fever. Those with heavy loss have pallor, dizziness and fast pulse.

• Pulse, blood pressure and bleeding on the pad as markers of severity.
• Cervical lesion, polyp or uterine tenderness on examination.
• Differential diagnosis: anovulatory bleeding, miscarriage or ectopic pregnancy, retained products, fibroids, adenomyosis, polyp, endometrial hyperplasia or cancer, cervical lesion, pelvic inflammatory disease, hormonal breakthrough or withdrawal bleeding, bleeding disorder, anticoagulant effect, trauma or foreign body.
• Complications: haemorrhagic shock, severe anaemia, transfusion, recurrent bleeding, hysterectomy, infection, delayed diagnosis of cancer.

The approach is triage by haemodynamic state, pregnancy test, and tests for the likeliest causes.

• Pulse, blood pressure, respiratory rate, oxygen saturation, amount of bleeding; speculum and bimanual examination.
• Urine hCG; full blood count and platelets, coagulation screen and fibrinogen if heavy; ferritin; thyroid stimulating hormone; group and cross-match if heavy bleeding or unstable.
• Chlamydia and gonorrhoea tests, high vaginal swab, cervical screening if due; transvaginal ultrasound for retained tissue, fibroids, polyps and endometrial thickness.
• Endometrial sampling or hysteroscopy once stable, if age is 45 years or above, or if bleeding recurs.

The principle is to resuscitate the unstable woman, treat the stable woman with oral drugs, and plan a follow-up diagnosis and long term treatment.

• Supportive: unstable woman: two large-bore cannulae, Ringer's lactate 1 to 2 litres rapidly, oxygen, urinary catheter and admission; stable woman: rest, fluids, pad count and review within 48 hours; iron rich diet; avoid aspirin.
• Pharmacological: tranexamic acid 1 g oral 8-hourly for up to 5 days (1 g IV over 10 minutes if unable to take oral; maximum 4 g daily; avoid in previous clot); mefenamic acid 500 mg oral 8-hourly with food for up to 5 days; norethisterone 5 mg oral 8-hourly for 10 days; or combined oral contraceptive pill with ethinylestradiol 30 micrograms and levonorgestrel 150 micrograms, one tablet oral 8-hourly for 7 days then one tablet once daily for 21 days (not in previous clot, migraine with aura or hypertension); chlamydia: doxycycline 100 mg oral 12-hourly for 7 days; gonorrhoea: ceftriaxone 1 g IM as a single dose; pelvic inflammatory disease: ceftriaxone 1 g IM once, then doxycycline 100 mg oral 12-hourly plus metronidazole 400 mg oral 12-hourly for 14 days; ferrous sulphate 200 mg oral 12-hourly for 3 months; iron sucrose 200 mg IV in 100 mL sodium chloride 0.9 percent over 30 minutes on alternate days for 3 to 5 doses for haemoglobin below 8 g/dL; desmopressin 0.3 micrograms/kg IV over 30 minutes for known von Willebrand disease.
• Procedures: intrauterine balloon tamponade with a Foley catheter inflated with 30 mL sodium chloride 0.9 percent for 12 to 24 hours with antibiotic cover; suction evacuation of retained tissue; hysteroscopic polypectomy; uterine artery embolisation; hysterectomy for uncontrolled bleeding; transfusion of packed red cells for haemoglobin below 7 g/dL or instability.
• Special groups: women with positive pregnancy tests need urgent ultrasound, with misoprostol 800 micrograms sublingual once or surgical evacuation for miscarriage and laparoscopy for ectopic pregnancy; adolescents have a bleeding disorder screen and norethisterone or the combined pill with iron; women on anticoagulants have the drug reviewed with the specialist and a levonorgestrel intrauterine system planned; women aged 45 years or above have endometrial sampling after the acute bleed settles.
• Red flags: systolic blood pressure below 90 mmHg, pulse above 120 per minute, haemoglobin below 7 g/dL, syncope, bleeding that does not slow after 24 hours, positive pregnancy test with pain, fever above 38 degrees Celsius, foul discharge.
• Follow-up: review at 48 hours for response; haemoglobin at 1 week; review at 3 months with menstrual diary; long term treatment (levonorgestrel intrauterine system, cyclical progestogen or surgery) matched to the cause; endometrial sampling for risk factors.