What are the options for progesterone-based prescription birth control?

Progesterone-Based Prescription Birth Control Options

Progesterone-only contraceptive methods include progestin-only pills (POPs), injectable contraceptives, implants, and hormonal IUDs, with long-acting reversible contraceptives (LARCs) offering the highest effectiveness rates and requiring minimal user compliance. 1

Progestin-Only Pills (POPs)

Mechanism and Effectiveness

• Work primarily by thickening cervical mucus, though some newer formulations also inhibit ovulation 1
• Typical failure rates vary:
  • Traditional POPs: Higher failure rates than combined hormonal methods due to strict adherence requirements 1
  • Newer formulations (e.g., desogestrel 75 mcg): Comparable effectiveness to combined pills with Pearl index of 0.14-0.41 2

Administration

• Must be taken at the same time each day
• 12-hour window for newer desogestrel formulations 2
• No hormone-free interval (taken continuously) 1

Advantages

• Safe for women with contraindications to estrogen 1, 3
• Can be used immediately postpartum in both breastfeeding and non-breastfeeding women 1
• Suitable during lactation without affecting milk production 2

Common Side Effects

• Irregular bleeding patterns (most common reason for discontinuation) 4
• Breakthrough bleeding, spotting, or prolonged bleeding 4
• Less overall bleeding with newer formulations like desogestrel 2

Special Considerations

• Requires very strict adherence with traditional formulations
• If vomiting/diarrhea occurs within 3 hours of taking pill:
  • Take another pill as soon as possible
  • Continue daily pills at regular time
  • Use backup contraception until 2 days after symptoms resolve 1

Injectable Progestin (Depot Medroxyprogesterone Acetate)

Mechanism and Effectiveness

• Highly effective with 0.3% failure rate with both perfect and typical use 5
• Administered every 3 months (13 weeks) 5

Administration

• Intramuscular injection
• Can be started immediately postpartum in both breastfeeding and non-breastfeeding women 1

Advantages

• Long-acting (3 months)
• No daily adherence required
• Effectiveness not dependent on body weight 5

Important Considerations

• Bone mineral density (BMD) loss should be considered, particularly in adolescents 5
• Return to fertility may be delayed after discontinuation
• Must return every 13 weeks for reinjection 5

Progestin Implant (Nexplanon)

Effectiveness and Duration

• Extremely effective (0.2% failure rate) 5
• Lasts for up to 3-5 years

Administration

• Subdermal implant placed in upper arm
• Can be inserted immediately postpartum in both breastfeeding and non-breastfeeding women 1

Advantages

• Long-acting
• No user compliance required after insertion
• Rapid return to fertility after removal

Levonorgestrel IUD (Mirena)

Effectiveness and Duration

• Highly effective long-term contraception
• Lasts 3-7 years depending on specific product

Administration

• Inserted into uterus by healthcare provider
• Can be inserted immediately postpartum (within 10 minutes of placental delivery) or after 4 weeks postpartum 1

Advantages

• Long-acting
• No daily adherence required
• Often reduces menstrual bleeding
• Local hormone action with minimal systemic effects

Emergency Contraception Options

Progestin-Only Emergency Contraception

• Levonorgestrel 1.5 mg as a single dose 1
• Most effective when taken within 72 hours of unprotected intercourse
• Can be taken up to 5 days after unprotected intercourse 1
• May be less effective in women weighing more than 165 pounds 1

Ulipristal Acetate

• 30 mg single dose
• More effective than levonorgestrel at 3-5 days after unprotected intercourse 1
• May be more effective in women with higher body weight 1

Clinical Decision-Making Algorithm

1. Assess contraindications to estrogen

   • If present: Consider progestin-only methods
   • If absent: Both combined and progestin-only methods are options

2. Evaluate patient reliability for daily medication

   • High reliability: Any method suitable
   • Low reliability: Consider LARC methods (implant, injection, IUD)

3. Consider breastfeeding status

   • Breastfeeding: Progestin-only methods preferred, especially in first 6 months 3
   • Non-breastfeeding: All methods appropriate based on other factors

4. Assess bleeding pattern preferences

   • Regular cycles desired: Combined methods preferred over POPs
   • Amenorrhea acceptable/desired: Consider injection or hormonal IUD

5. Consider duration preferences

   • Short-term: POPs offer quick reversibility
   • Long-term: Implant or IUD provides 3-7 years of protection

Common Pitfalls to Avoid

• Timing errors with POPs: Unlike combined pills, traditional POPs have a much stricter timing window (3 hours)
• Underestimating POP effectiveness: Newer formulations like desogestrel have comparable effectiveness to combined pills 2
• Inadequate counseling about bleeding patterns: Irregular bleeding is common with all progestin-only methods and is the main reason for discontinuation 4
• Missing follow-up injections: DMPA must be administered every 13 weeks for continued effectiveness 5
• Overlooking drug interactions: Some medications may reduce contraceptive effectiveness of hormonal methods