Levonorgestrel capsule implants in the United States: a 5-year study

Area of Science:

• Reproductive Health
• Contraception
• Pharmacology

Background:

• Levonorgestrel implants are a Food and Drug Administration-approved contraceptive option.
• Long-term effectiveness, safety, and acceptability data are crucial for clinical decision-making.

Purpose of the Study:

• To evaluate the 5-year effectiveness, adverse event profile, and user acceptability of levonorgestrel implants.
• To identify factors influencing the outcomes of contraceptive implant use.

Main Methods:

• Prospective, multicenter study involving 511 women using contraceptive implants.
• Monitoring included regular follow-ups, adverse event assessment, and pregnancy testing.
• Statistical analyses included lifetable methods and Cox regression to determine continuation rates and influencing factors.

Main Results:

• A low 5-year cumulative pregnancy rate of 1.3% was observed, with no pregnancies in women weighing under 79 kg.
• The most common reason for removal was prolonged or irregular menstrual bleeding, followed by headache, weight gain, and mood changes.
• Annual continuation rates exceeded 80%, with younger women showing lower continuation rates compared to older women.

Conclusions:

• Levonorgestrel implants demonstrate high effectiveness and acceptability for up to 5 years.
• Contraceptive implant effectiveness remains consistent regardless of age or family planning status.
• The 5-year pregnancy rate is comparable to that of tubal ligation, highlighting its efficacy as a long-term reversible contraceptive method.