Amenorrhoea on Contraception

Amenorrhoea during hormonal contraception is absence of bleeding for 3 or more months in a patient using a hormonal method. It is expected with injectables, frequently seen with implants, progestin-only pills and levonorgestrel intrauterine devices, and can occur with continuous or extended combined regimens. It is not harmful and needs no treatment, but patients should be told to expect it, because unexplained amenorrhoea raises the question of pregnancy.

Expected frequency. By the end of the first year of DMPA, amenorrhoea develops in the majority of patients. It is more variable with implants and levonorgestrel devices. It is common in breastfeeding patients on progestin-only methods.

History. Method and start date, missed or late doses, interacting medicines, symptoms of pregnancy, breastfeeding status, weight change, galactorrhoea, hot flushes, headache or visual change, stress and illness.

Examination. Blood pressure, weight, breast examination, abdominal examination, and speculum and bimanual examination if pregnancy is suspected or symptoms are present.

Pregnancy. Exclude when amenorrhoea follows previous regular bleeding, after missed pills or a late injection, after an interacting medicine, with pregnancy symptoms, or in an intrauterine device user. A pregnancy test is advised, because injectable users may have amenorrhoea without pregnancy and a physical examination alone may not exclude it.

Differential diagnosis. Pregnancy, expected method effect, lactational amenorrhoea, polycystic ovary syndrome, hyperprolactinaemia, thyroid disease, premature ovarian insufficiency, perimenopause, hypothalamic causes (low weight, intensive exercise, stress), intrauterine adhesions, and pituitary disease.

Investigations. Pregnancy test. If not pregnant and symptoms suggest another cause or amenorrhoea persists for over 6 months after stopping an injectable, measure thyroid stimulating hormone and prolactin, and follicle stimulating hormone when menopause is suspected.

Not pregnant. Reassure and continue the method. No treatment is needed. Explain that the endometrium is thin, that blood is not retained, that fertility is not harmed and that return of menses is expected after stopping.

Pregnant. Stop the pill, injectable or patch. Remove the implant, or leave it in place only while arranging removal. Remove an intrauterine device if the strings are visible and the pregnancy is within the first 3 months. Exclude ectopic pregnancy. Provide antenatal care or other options in line with the law. There are no known risks to the foetus from hormonal contraception taken during pregnancy.

Breastfeeding. Absence of menses while breastfeeding is normal. Reassure.

Patient distressed despite reassurance. Offer another method. Options include a combined method for patients with no category 3 or 4 condition, or a method that preserves bleeding such as a copper intrauterine device.

Combined pill specific. Assess for pregnancy. Reassure if not pregnant. Advise taking pills at the same time each day.

Injectable specific. Reassure that amenorrhoea develops in most users by the end of the first year and needs no medical treatment. If still bothered, stop the injectable and help choose another method.

Follow up. Annual review. Return sooner for symptoms of pregnancy, pelvic pain, breast changes or headaches.

Method decisions. Continue when acceptable. Switch when unacceptable. Return of menses after stopping an injectable can take months, and fertility returns later than with other methods.

Referral and escalation. Refer suspected ectopic pregnancy, amenorrhoea persisting beyond 6 months after stopping an injectable with raised prolactin or abnormal thyroid function, galactorrhoea with headache or visual change, and suspected premature ovarian insufficiency.