Preface—updating DMPA safety

Abstract

Depot-medroxyprogesterone acetate (DMPA) is currently used for contraception by about nine million women in more than 90 countries. DMPA injected intramuscularly at a dose of 150 mg every 3 months is among the most effective reversible contraceptive methods. The reluctance of the US Food and Drug Administration (FDA) to approve DMPA in 1992 was attributed to the occurrence of mammary neoplasia in beagle dogs and of endometrial cancer in two of sixteen rhesus monkeys after long-term DMPA treatment. The beagle dog responds to DMPA with a release of growth hormone which is probably the cause of the tumorigenic effect of DMPA on the mammary gland. Around 1990 findings were published from a WHO multicenter study in Kenya Mexico and Thailand and studies from Costa Rica and New Zealand. In 1993 a WHO meeting of experts reviewed the available data on use of DMPA and cancer risk in women as well as recent toxicology data. DMPA exerts a protective effect against endometrial cancer. The epidemiological studies report no association between the risk of ovarian cancer and the use of DMPA. There was a lack of an association between cervical cancer and DMPA. Two well-designed epidemiological studies did not provide evidence for an increase in overall risk of breast cancer among women having used DMPA. However both studies reported a weak association between current and recent use of DMPA and breast cancer although there was no evidence of increased risk for women who had stopped using DMPA several years ago. Women who were less than 35 years old at diagnosis an age at which breast cancer is rare also showed a slightly increased risk. DMPA can cause an irregular bleeding pattern it is not immediately irreversible and there is a relatively slow return of fertility after discontinuation. Yet for women who wish for medium- or long-term contraception DMPA is one of the alternatives to be considered.