What are the benefits and risks of Depo-Provera (medroxyprogesterone acetate) birth control for a woman of reproductive age?

Depo-Provera Birth Control: Key Information

Effectiveness

Depo-Provera (depot medroxyprogesterone acetate, DMPA) is a highly effective contraceptive with a typical-use failure rate of approximately 6% in the first year, comparable to modern IUDs and superior to many other methods. 1 The contraceptive efficacy exceeds 99% with perfect use. 2

• DMPA is administered as 150 mg intramuscularly or 104 mg subcutaneously every 13 weeks (up to 15 weeks). 1
• Ovulation is suppressed for at least 14 weeks after a single 150 mg dose. 2
• The method can be initiated mid-cycle with a "quick start" approach if pregnancy is reasonably excluded, with backup contraception needed for the first 7 days. 1
• Self-administration of the subcutaneous formulation is now supported, with studies showing 12-month continuation rates of 1.27 times higher than provider-administered methods. 1

Major Benefits

• Convenience: Requires only quarterly injections rather than daily adherence, eliminating the "fear of forgetting" associated with daily methods. 3
• Menstrual benefits: Reduces menstrual blood loss, improves dysmenorrhea, and protects against iron-deficiency anemia. 1
• Cancer protection: Provides prolonged protective effect against endometrial cancer with no increased overall risk of breast, ovarian, liver, or cervical cancer in long-term surveillance studies. 4
• Medical advantages: Safe for lactating women, may raise seizure threshold in epilepsy, may decrease sickle cell crises, and reduces risk of pelvic inflammatory disease. 1, 2
• Cardiovascular safety: No appreciable effects on blood pressure or thrombosis risk, making it suitable for women who cannot use combined hormonal contraceptives. 3

Critical Risks and Side Effects

Bone Mineral Density Loss (Most Serious Concern)

The FDA issued a black box warning in 2004 regarding significant bone mineral density (BMD) loss with DMPA use, though subsequent evidence shows substantial recovery after discontinuation. 1, 4

• Adult women using DMPA for 5 years show spine and hip BMD decreases of 5-6%, with the most pronounced decline in the first 2 years. 4
• Adolescents show even greater concern: at 4.6 years of use, lumbar spine BMD decreased 4.17% while untreated controls gained 5.12%. 4
• BMD partially recovers after discontinuation, but recovery may be incomplete with longer duration of use. 1, 4
• The American College of Obstetricians and Gynecologists does NOT recommend limiting use to 2 years or routine BMD monitoring, as preventing unwanted pregnancy outweighs bone density concerns. 1, 5
• DMPA should be used long-term (>2 years) only if other methods are inadequate, per FDA labeling. 4

All patients must receive counseling on skeletal health measures: 1300 mg calcium daily, 600 IU vitamin D, regular weight-bearing exercise, and smoking cessation. 1, 5

Menstrual Irregularities

• Nearly all users experience menstrual disruption initially, typically irregular spotting and bleeding. 1, 4
• By 12 months, 55% of women experience amenorrhea; by 24 months, 68% have amenorrhea. 4
• Counseling about menstrual changes BEFORE the first injection significantly improves continuation rates. 1
• Irregular bleeding typically improves over time and rarely requires surgical intervention. 3

Weight Gain

• Weight gain is common, though not universal. 1, 5
• Weight gain status at 6 months strongly predicts future excessive weight gain: patients gaining >5% body weight at 6 months are at high risk for significant BMI increases with continued use. 1, 5
• Studies show 21% of adolescents experience early excessive weight gain. 1

Delayed Return to Fertility

• Return to fertility typically takes 9-18 months after discontinuation, regardless of subcutaneous or intramuscular formulation. 1, 5, 2
• This delay occurs while the endometrial lining recovers and ovulatory function returns. 5
• DMPA does not cause permanent infertility. 2

Other Side Effects

• Headache, breast tenderness (mastalgia), hair loss, and changes in libido may occur. 1, 5
• Injection site reactions are more common with self-administered subcutaneous formulations. 1

Contraindications

Absolute contraindications include: 6

• History of stroke or myocardial infarction
• Current or history of pulmonary embolism or deep vein thrombosis
• History of neurofibromas or meningiomas (DMPA may stimulate tumor growth)

Relative contraindications/special precautions: 1, 6

• Positive antiphospholipid antibodies
• High risk for osteoporosis (metabolic bone disease, chronic corticosteroid use, anorexia nervosa, strong family history)
• Active smoking combined with other risk factors

NOT contraindications: 6

• Past history of pelvic inflammatory disease (only current PID is contraindicated)
• HIV infection or immunosuppression
• Adolescent age (though bone density concerns require thorough counseling)

Special Populations

Adolescents

• DMPA is appropriate for adolescents with proper counseling about bone density effects. 1
• Particularly useful for those with complex medical conditions requiring menstrual suppression when estrogen is contraindicated. 1
• Scheduling visits every 11-12 weeks (rather than 13) allows buffer for missed appointments. 1

Women with Rheumatic Diseases

• Safe in most women with rheumatic and musculoskeletal diseases, with 3% typical-use failure rate. 1
• Exceptions: positive antiphospholipid antibodies or high osteoporosis risk. 1

Postpartum and Lactating Women

• Safe for breastfeeding women with no adverse effects on lactation. 7
• Provides advantage over combined hormonal methods in this population. 7

Clinical Pitfalls to Avoid

• Do not assume amenorrhea after 3 years is solely due to DMPA: Rule out pregnancy and other causes, especially if amenorrhea persists beyond 18 months post-discontinuation. 8
• Do not fail to counsel about menstrual changes before initiation: Pre-injection counseling dramatically improves continuation rates. 1, 3
• Do not ignore early weight gain: Patients gaining >5% at 6 months need counseling about risk of continued excessive weight gain. 1
• Do not automatically limit use to 2 years: ACOG does not recommend this restriction, though FDA labeling suggests using long-term only if other methods inadequate. 1, 5, 4
• Do not forget STI protection counseling: DMPA provides no protection against sexually transmitted infections; condoms must be used concurrently for STI prevention. 1

Monitoring Recommendations

• No routine BMD monitoring is recommended by ACOG, though BMD evaluation should be considered when women need to continue long-term use. 4
• For adolescents, BMD interpretation must account for patient age and skeletal maturity. 4
• Evaluate for other osteoporosis risk factors when considering long-term use. 5
• If abnormal bleeding persists or is severe, investigate to rule out organic pathology. 4