Risks of Long-Term Depo Provera Use Beyond 2 Years
Despite the FDA's black box warning about bone mineral density loss, the American College of Obstetricians and Gynecologists (ACOG) does not advise limiting Depo Provera use to 2 years or routinely monitoring bone density after this timeframe, as the benefits of preventing unwanted pregnancy generally outweigh the risks of bone density loss. 1
Bone Health Concerns
- Depo Provera causes reductions in bone mineral density (BMD), which prompted the FDA to issue a black box warning in 2004 1
- Subsequent research has shown substantial recovery of BMD after discontinuation of Depo Provera 1
- The risk of decreased BMD increases with longer duration of use, particularly beyond 2 years 2
- Despite these concerns, ACOG does not recommend limiting use to 2 years due to the risk of unwanted pregnancy if contraceptive options are limited 1
Menstrual Changes
- Nearly all patients experience menstrual irregularities initially, which typically improve over time 1
- With continued use beyond 2 years, amenorrhea becomes increasingly common, reported by 57% of women after one year of treatment 3
- These menstrual changes are generally not harmful but may affect patient satisfaction and continuation rates 1
Weight Gain
- Weight gain is a common side effect with long-term use 1
- Studies in both adolescents and adults suggest that weight gain status at 6 months is a strong predictor of future excessive weight gain with ongoing DMPA use 1
- Not all patients experience weight gain, but those who show early weight gain (>5% at 6 months) may experience significant increases in BMI with continued use 1
Return to Fertility
- Long-term DMPA use is associated with a delayed return to fertility, typically 9 to 18 months after discontinuation 1
- This delay occurs while the endometrial lining returns to its pre-DMPA state and ovulatory function returns 1
- Both subcutaneous and intramuscular DMPA formulations show similar delays to fertility after injection 1
Other Potential Side Effects
- Headache, mastalgia (breast pain), hair loss, and changes in libido may occur with continued use 1
- Long-term studies have shown no increased risk for ovarian, liver, or cervical cancer 3
- DMPA may actually reduce the risk of endometrial cancer with extended use 3
Recommendations for Patients Using Depo Provera Long-Term
- All patients using DMPA beyond 2 years should be counseled about measures to promote skeletal health 1:
- Daily intake of 1300 mg of calcium and 600 IU of vitamin D
- Regular weight-bearing exercise
- Smoking cessation
- Patients should be evaluated for other risk factors for osteoporosis when considering long-term use 1
- Annual healthcare visits are recommended for blood pressure checks and other healthcare needs during treatment 2
Clinical Considerations
- For patients with risk factors for osteoporosis (family history, chronic alcohol or tobacco use, eating disorders, or illness requiring chronic corticosteroid use), alternatives to DMPA may be preferable for long-term contraception 1
- The convenience of DMPA (injections every 13 weeks) makes it an attractive option for many patients who have difficulty with daily, weekly, or monthly contraceptive methods 1
- Counseling about potential side effects before initiation improves continuation rates 1
Despite the concerns about bone health, the evidence suggests that for most women, the benefits of Depo Provera as an effective contraceptive method outweigh the risks, even with use beyond 2 years. However, individual risk factors should be considered, and bone health measures should be encouraged for all long-term users.