Breakthrough Bleeding

Breakthrough bleeding is unscheduled vaginal bleeding or spotting that occurs while a woman is using hormonal contraception or hormone therapy. It is caused by endometrial instability from low or fluctuating hormone levels, missed pills, drug interactions, vomiting and diarrhoea, smoking, pregnancy, infection and cervical or uterine disease. It is very common in the first 3 months of use, and matters because it is a common reason for stopping a method.

• Risk factors: first 3 months of combined pill, progestogen-only pill, implant, depot injection or hormonal intrauterine system; missed pills; smoking; low dose pills; interacting drugs (rifampicin, efavirenz, carbamazepine, phenytoin).
• Settles in most women within 3 months.
• Bleeding that persists or starts after months of stable use needs assessment.

Women have light spotting or heavier bleeding at unexpected times during the use of the pill, implant, injection or hormonal intrauterine system, often without pain.

• Light bleeding or spotting for several days between withdrawal bleeds.
• Normal abdominal and pelvic examination.
• Differential diagnosis: normal adaptation to contraception, missed or delayed pills, interacting drugs, pregnancy or ectopic pregnancy, chlamydia or gonorrhoea cervicitis, cervical ectropion or polyp, endometrial polyp, cervical or endometrial cancer, fibroids, thyroid disease.
• Complications: method discontinuation and unintended pregnancy, anaemia, anxiety, missed doses, delayed diagnosis of infection or cancer.

The approach is a history of method use and exclusion of other causes.

• Method, duration, missed doses, vomiting, diarrhoea, drugs (including herbal products), smoking and sexual history.
• Urine hCG; speculum and bimanual examination; chlamydia and gonorrhoea tests, cervical screening if due.
• Transvaginal ultrasound if bleeding persists beyond 3 months or is heavy; full blood count if heavy.
• Endometrial sampling if age is 45 years or above, or persistent bleeding with risk factors.

The principle is reassurance in the first 3 months, correction of causes, and a short course of drug treatment or a change of method if bleeding persists.

• Supportive: reassurance that bleeding usually settles within 3 months; take pills at a fixed hour daily using an alarm; correct missed pills; stop smoking; condom use for infection.
• Pharmacological: implant bleeding: mefenamic acid 500 mg oral 8-hourly with food for 5 days, or ibuprofen 400 mg oral 8-hourly with food for 5 days, or tranexamic acid 1 g oral 8-hourly for 5 days; combined oral contraceptive pill with ethinylestradiol 30 micrograms and levonorgestrel 150 micrograms oral once daily for 21 days as an add-on for implant or progestogen-only bleeding if oestrogen is not contraindicated; combined pill breakthrough: after correct use is confirmed, change to a pill containing ethinylestradiol 30 micrograms if the current pill has a lower dose, or to a continuous regimen; chlamydia: doxycycline 100 mg oral 12-hourly for 7 days; gonorrhoea: ceftriaxone 1 g IM as a single dose; ferrous sulphate 200 mg oral 12-hourly for 3 months for anaemia.
• Procedures: removal of the implant or intrauterine system if bleeding is unacceptable; hysteroscopy for persistent bleeding; none otherwise.
• Special groups: women taking rifampicin, efavirenz, carbamazepine, phenytoin or phenobarbital use depot medroxyprogesterone 150 mg IM every 13 weeks, a copper intrauterine device or the levonorgestrel intrauterine system, since these drugs reduce the effect of pills and implants; women who cannot use oestrogen (migraine with aura, hypertension, previous clot) use progestogen-only options for bleeding control.
• Red flags: heavy bleeding, positive pregnancy test with pain, bleeding after intercourse, pelvic pain with fever, bleeding persisting beyond 6 months of use, age above 45 years with new pattern.
• Follow-up: review at 3 months; change of method if bleeding persists and is unacceptable; repeat tests if bleeding recurs after a long period of stable use.