Ovulatory Abnormal Uterine Bleeding

Ovulatory abnormal uterine bleeding is abnormal bleeding (usually heavy or prolonged) in a woman who has regular cycles with ovulation, confirmed by regular periods and a midluteal progesterone above 30 nmol/L.

Causes are structural (polyp, adenomyosis, leiomyoma) and nonstructural (coagulopathy, endometrial disorders, iatrogenic effects), and the bleeding results from local endometrial abnormalities, increased prostaglandin production or reduced vasoconstriction.

It matters because it is a common pattern of heavy menstrual bleeding, and it responds well to nonhormonal and hormonal treatment.

• Risk factors: copper intrauterine device, anticoagulants, bleeding disorders, endometrial polyps, adenomyosis, fibroids, previous caesarean section, thyroid disease.
• The cycle is regular, at 24 to 38 days, with premenstrual symptoms.
• Ovulation is confirmed before the diagnosis is made.

Women have regular periods that are heavy or prolonged, often with premenstrual breast tenderness, mood change and cramping pain, and sometimes clots and flooding. Examination may show an enlarged uterus.

• Regular cycle length of 24 to 38 days on the menstrual diary.
• Pallor and tachycardia if anaemic.
• Differential diagnosis: anovulatory bleeding, endometrial polyp, adenomyosis, fibroids, endometrial hyperplasia or cancer, bleeding disorder, chronic endometritis, caesarean scar niche, hypothyroidism, intrauterine device effect, anticoagulant effect.
• Complications: iron deficiency anaemia, fatigue, reduced quality of life, hysterectomy, hospital admission.

The approach is to confirm ovulation, exclude pregnancy and find structural or systemic causes.

• Urine hCG; menstrual diary; midluteal progesterone (day 21 of a 28 day cycle, above 30 nmol/L confirms ovulation).
• Full blood count and ferritin; thyroid stimulating hormone; coagulation screen, von Willebrand antigen and activity, platelet function if bleeding began at menarche.
• Transvaginal ultrasound (polyp, fibroid, adenomyosis, scar niche, endometrial thickness); sonohysterography or hysteroscopy for cavity lesions.
• Endometrial sampling if age is 45 years or above, or persistent bleeding despite treatment.

The principle is first line medical treatment with the levonorgestrel intrauterine system or tranexamic acid, then surgery for structural disease or failure of drug treatment.

• Supportive: menstrual diary; iron rich diet; reassurance that bleeding is regular; weight management; stop smoking.
• Pharmacological: levonorgestrel intrauterine system 52 mg for 5 years; tranexamic acid 1 g oral 8-hourly for up to 4 days during bleeding (maximum 4 g daily); mefenamic acid 500 mg oral 8-hourly with food for up to 5 days; combined oral contraceptive pill with ethinylestradiol 30 micrograms and levonorgestrel 150 micrograms oral once daily for 21 days then 7 days free; norethisterone 5 mg oral 8-hourly on days 5 to 26 of the cycle; ferrous sulphate 200 mg oral 12-hourly for 3 to 6 months; doxycycline 100 mg oral 12-hourly for 14 days for chronic endometritis; levothyroxine 50 micrograms oral once daily increased every 4 to 6 weeks for hypothyroidism.
• Procedures: hysteroscopic polypectomy or fibroid resection; endometrial ablation after childbearing; uterine artery embolisation or myomectomy for fibroids; hysterectomy for failure of other treatment.
• Special groups: women with bleeding disorders have desmopressin 0.3 micrograms/kg IV over 30 minutes, or intranasal 300 micrograms (150 micrograms below 50 kg), with tranexamic acid under haematology advice; women with previous clot avoid combined pills and tranexamic acid and use the levonorgestrel intrauterine system; women with renal impairment have tranexamic acid 15 mg/kg (usually 1 g) oral 12-hourly when creatinine is 120 to 249 micromol/L.
• Red flags: haemoglobin below 8 g/dL, flooding with syncope, intermenstrual bleeding, endometrial thickness above 12 mm, pelvic mass, no response to 3 months of treatment.
• Follow-up: review at 3 months with menstrual diary and haemoglobin; ferritin at 3 months; surgical referral after 6 months of failed medical treatment.