Withdrawal Bleeding

Withdrawal bleeding is bleeding from the endometrium that occurs after stopping oestrogen and progestogen, for example in the pill-free week of the combined contraceptive pill, after a progestogen challenge, or after stopping hormone therapy. It results from a fall in hormone levels that causes the hormone primed endometrium to shed. It matters because the presence or absence of a bleed is a diagnostic test of the uterus and oestrogen status, and because it is not a true period.

• Occurs within 2 to 7 days of stopping the hormone.
• Absence suggests pregnancy, low oestrogen, outflow obstruction or uterine scarring.
• Heavy bleeding after a long gap may need medical control.

Women have a bleed that is lighter than, or comparable to, a period, lasting 3 to 7 days, after the last hormone tablet or after stopping a progestogen course. Some have heavy or prolonged bleeding after long amenorrhoea.

• Bleeding within a week of stopping the hormone.
• Absent bleeding when the endometrium is thin or the outflow tract is blocked.
• Differential diagnosis: normal withdrawal bleed, true period, anovulatory bleeding, breakthrough bleeding, miscarriage or ectopic pregnancy, endometrial hyperplasia, Asherman syndrome, outflow obstruction, premature ovarian insufficiency, hypothalamic amenorrhoea.
• Complications: heavy bleeding with anaemia after long amenorrhoea, anxiety from absent bleeding, missed pregnancy, delayed diagnosis of low oestrogen state.

The approach is to understand the reason for the bleed and to exclude pregnancy when no bleed occurs.

• History of the hormone used, timing, missed pills and sexual activity; urine hCG when a bleed is absent.
• Progestogen challenge: medroxyprogesterone 10 mg oral once daily for 10 days; bleeding within 7 days of finishing shows oestrogen present and a patent outflow tract.
• Follicle stimulating hormone, oestradiol, prolactin, thyroid stimulating hormone; pelvic ultrasound; hysteroscopy if scarring is suspected.
• Oestrogen and progestogen challenge when there is no bleed after progestogen alone.

The principle is to explain that the bleed is normal, to use withdrawal bleeding as a test where needed, and to treat heavy bleeding or the underlying cause.

• Supportive: reassurance that the bleed is expected and not a true period; take pills on time; counsel about skipping the pill free week to avoid bleeding if wanted; check pregnancy if the bleed is absent.
• Pharmacological: no bleed after progestogen: oestradiol valerate 2 mg oral once daily for 21 days with medroxyprogesterone 10 mg oral once daily added for the last 10 days; to avoid withdrawal bleeds: combined oral contraceptive pill with ethinylestradiol 30 micrograms and levonorgestrel 150 micrograms oral once daily taken continuously for 3 months without a break; heavy withdrawal bleeding: tranexamic acid 1 g oral 8-hourly for 4 days and mefenamic acid 500 mg oral 8-hourly with food for 3 days; premature ovarian insufficiency: oestradiol valerate 2 mg oral once daily with medroxyprogesterone 10 mg oral once daily for 12 days each month, until about age 50 years.
• Procedures: hysteroscopic adhesiolysis for uterine adhesions; none otherwise.
• Special groups: women with premature ovarian insufficiency use hormone therapy until the natural age of menopause for bone and heart protection; women with endometrial hyperplasia have progestogen exposure and endometrial review; women with migraine with aura or previous clot avoid oestrogen and use progestogen-only withdrawal.
• Red flags: no bleed with a positive pregnancy test, heavy bleeding after long amenorrhoea, no bleed after oestrogen and progestogen (uterine scarring or outflow obstruction), severe pain, fever.
• Follow-up: review at 3 months; repeat challenge if needed; bone density scan if low oestrogen; fertility counselling.