Injectable contraception with depot medroxyprogesterone acetate. Current status.

Abstract

Depot medroxyprogesterone acetate (DMPA) the only injectable contraception approved in the United States in 1992 is used by 8-9 million women in more than 90 countries. DMPA inhibits ovulation by the reduction of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) plasma levels. The contraceptive efficacy of the usual dosage of 150 mg every 3 months is extremely high. In a World Health Organization-sponsored multi-center study no pregnancies were reported among 607 women (452 patient-years) using this regimen. Other trials have reported failure rates ranging from zero to 0.7% of women experiencing an accidental pregnancy during 1 year of use. The typical failure rate has been estimated as 0.3% which is comparable to the contraceptive efficacy of subdermal implants or tubal sterilization. Use of 300 mg every 6 months is associated with a higher failure rate of 2.3%. Following injection of 150 mg ovulation does not occur for at least 14 weeks. DMPA should be initiated within 5 days of delivery and the first Depo-Provera injection should be deferred until 6 weeks postpartum in nursing women. Episodes of irregular bleeding and spotting lasting 7 days are frequent during the first months of use. About 50% of women using DMPA for 1 year have amenorrhea. Women with diabetes should be monitored while using DMPA; but use of DMPA was not associated with significant changes in coagulation parameters. A 1979 WHO study found no increased risk of breast cancer in users on the other hand it markedly reduced the risk of endometrial cancer for 8 years following discontinuation. Bone density in 30 women who had used DMPA for 5 years was lower than in non-users although osteoporosis was not evident. Almost 70% of DMPA former users conceived within 12 months after discontinuation. Headache dizziness abdominal bloating mood changes alopecia and weight gain may occur in DMPA users. DMPA is particularly suitable for women with hemoglobinopathy. DMPA is safe and effective in appropriately selected patients.