Contraceptive Recommendations for a 16-Year-Old with BMI 35 and High STI Risk
This adolescent should receive a long-acting reversible contraceptive (LARC)—specifically the etonogestrel implant or levonorgestrel IUD—as first-line contraception, combined with mandatory condom use at every sexual encounter for STI prevention. 1
Primary Contraceptive Method: LARC
LARC methods are the optimal choice for this patient, with no contraindications related to her age, obesity, or nulliparous status:
The etonogestrel implant is classified as Category 1 (no restrictions) for adolescents under 18 years, and all hormonal contraceptives and IUDs are safe for women with BMI ≥30, making her obesity not a contraindication. 1
LARC methods provide superior effectiveness compared to user-dependent methods, with implant failure rates of 0.05% and LNG-IUD failure rates of 0.2%, versus 9% for combined oral contraceptives. 1
These methods eliminate adherence concerns, which is critical for adolescents who demonstrate higher rates of inconsistent use with daily methods. 1
No physical examination is required before LARC insertion—only pregnancy testing if she is sexually active or if there is any possibility of sexual activity. 1
Mandatory Dual-Method Approach for STI Protection
Condoms must be used at every sexual encounter regardless of the LARC method, as hormonal contraceptives and IUDs provide zero protection against STIs:
Male latex condoms reduce transmission of HIV, gonorrhea, chlamydia, trichomoniasis, hepatitis B, herpes simplex virus, and human papillomavirus when used consistently and correctly. 1
This dual-method approach addresses both unintended pregnancy and STI prevention simultaneously, which is essential given her increased STI risk. 1
Research demonstrates that LARC users may be 60% less likely to use condoms compared to oral contraceptive users, making counseling about continued condom use absolutely critical. 2
Implementation Algorithm
Follow this specific sequence for contraceptive initiation:
Pregnancy testing: Perform urine pregnancy test if she is sexually active or if there is any possibility of sexual activity. 1
LARC insertion timing: Insert the implant or LNG-IUD at any time if reasonably certain she is not pregnant—do not delay waiting for menses. 1
Backup contraception: Use condoms for 7 days after insertion if not inserted during menses. 1
Condom counseling: Provide specific instructions on correct condom use, including water-based lubricants only and latex condoms as the preferred method. 1
Critical Pitfalls to Avoid
Common errors that compromise effectiveness:
Do not prescribe oral contraceptives as first-line when LARC is medically appropriate—this patient has no contraindications to LARC. 1
Do not assume she will continue condom use after LARC insertion; explicitly reinforce dual-method messaging at every encounter. 1
Never recommend spermicides for high STI-risk patients, as they do not provide adequate protection. 1
Natural membrane condoms do not protect against STIs and should never be used; female condoms are an alternative only when male condoms cannot be used properly. 1
Follow-Up Requirements
Ongoing management to maintain dual protection:
Screen for STIs at least annually, and more frequently if indicated based on her risk profile. 1
Reinforce dual-method messaging at each clinical encounter, as consistent condom use remains the major barrier to effective STI prevention among LARC users. 1, 3
Address the reality that LARC users with multiple sexual partners may no longer perceive a need for condoms even though they remain at high risk for STIs. 2
Why Not Progestin-Only Pills?
POPs are inferior to LARC for this patient:
POPs have typical-use failure rates of 9%, identical to combined oral contraceptives, making them significantly less effective than LARC methods. 4
POPs are appropriate for adolescents with contraindications to estrogen (such as history of VTE, hypertension, or migraine with aura), but this patient has no such contraindications. 4
For a healthy adolescent without estrogen contraindications, LARC methods are superior first-line options. 4