Frequent Menstruation

Frequent menstruation is more than 4 bleeding episodes in 90 days, or an interval between periods of less than 24 days, whether the pattern is regular or irregular.

Causes include anovulatory cycles in perimenopause or polycystic ovary syndrome, short ovulatory cycles, thyroid disease, endometrial polyps, adenomyosis, fibroids, pelvic infection, hormonal contraception and bleeding disorders.

It matters because repeated blood loss causes iron deficiency anaemia and because bleeding that is not explained needs exclusion of endometrial hyperplasia or cancer.

• Risk factors: age above 40 years, obesity, polycystic ovary syndrome, thyroid disease, intrauterine device or implant, pelvic infection, coagulation disorders, tamoxifen use.
• It differs from polymenorrhoea because it includes irregular and breakthrough bleeding.
• Persistent frequent bleeding after age 45 years needs endometrial sampling.

Women have bleeding episodes of variable length and flow that return more often than every 3 weeks, with tiredness, pallor and breathlessness if anaemic. There may be pelvic pain, discharge or postcoital bleeding.

• Menstrual diary with 5 or more bleeding days at intervals under 24 days.
• Pallor, tachycardia, enlarged or tender uterus.
• Differential diagnosis: polymenorrhoea, perimenopausal anovulatory bleeding, polycystic ovary syndrome, endometrial polyp, fibroids, adenomyosis, endometrial hyperplasia or cancer, cervical lesion, pelvic inflammatory disease, chlamydia cervicitis, hormonal contraceptive breakthrough bleeding, bleeding disorder, thyroid disease, pregnancy complication.
• Complications: iron deficiency anaemia, fatigue, reduced work and quality of life, infertility, endometrial hyperplasia, hospital admission for heavy bleeding.

The approach is to exclude pregnancy and structural or malignant disease, and to assess the effect on haemoglobin.

• Urine or serum hCG; menstrual diary; speculum examination of the cervix and bimanual pelvic examination.
• Full blood count, ferritin, thyroid stimulating hormone, coagulation screen and von Willebrand tests if heavy bleeding since menarche; high vaginal swab, chlamydia and gonorrhoea tests; cervical screening.
• Transvaginal ultrasound for polyps, fibroids, adenomyosis and endometrial thickness (above 12 mm needs sampling).
• Endometrial sampling or hysteroscopy for women aged 45 years or above, or younger women with persistent bleeding or risk factors for endometrial cancer.

The principle is to find and treat the cause, control bleeding and correct anaemia.

• Supportive: menstrual diary; dietary iron; reassurance when no cause is found; stop smoking; weight loss in obesity; review of drugs and devices that cause bleeding.
• Pharmacological: 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 during bleeding; combined oral contraceptive pill with ethinylestradiol 30 micrograms and levonorgestrel 150 micrograms oral once daily for 21 days then 7 days free, or continuous for 3 months; levonorgestrel intrauterine system 52 mg for 5 years; norethisterone 5 mg oral 8-hourly on days 5 to 26 of the cycle, or medroxyprogesterone 10 mg oral once daily for 10 to 14 days each month, when oestrogen is contraindicated; ferrous sulphate 200 mg oral 12-hourly for 3 months for anaemia; infection: ceftriaxone 1 g IM once plus doxycycline 100 mg oral 12-hourly for 14 days plus metronidazole 400 mg oral 12-hourly for 14 days for pelvic inflammatory disease; levothyroxine 50 micrograms oral once daily increased every 4 to 6 weeks for hypothyroidism.
• Procedures: hysteroscopic polypectomy or resection of submucous fibroid; endometrial ablation after childbearing; uterine artery embolisation or myomectomy for fibroids; hysterectomy for persistent bleeding that fails other treatment.
• Special groups: women who cannot take oestrogen (migraine with aura, hypertension, previous clot, smoking above age 35 years) use progestogen-only methods and the levonorgestrel intrauterine system; women with bleeding disorders have haematology care with tranexamic acid and desmopressin 0.3 micrograms/kg IV over 30 minutes, or intranasal 300 micrograms (150 micrograms below 50 kg), for von Willebrand disease; perimenopausal women have endometrial assessment if bleeding persists.
• Red flags: haemoglobin below 8 g/dL, bleeding that soaks a pad every hour, syncope, postcoital or postmenopausal bleeding, endometrial thickness above 12 mm, pelvic mass, fever with pelvic pain, weight loss.
• Follow-up: review at 3 months with menstrual diary and haemoglobin; endometrial assessment or referral if no response after 6 months; ferritin at 3 months; review of the levonorgestrel intrauterine system at 3 to 6 months for bleeding pattern.