Adapted from NEJM 2/2/2017 review article, “Long-Acting Reversible Contraception”:
- Unintended pregnancies are common in the US, though decreasing from 2008 to 2011: 45% of US pregnancies are unintended (compared to 35% in W Europe). 54/1000 in 2008 down to 45/1000 in 2011.
- From 2011-13, only 62% of women 15-44 yo were using contraception; IUDs were 10%, implants 1% – these highly effective methods are underutilized.
- IUDs: Cu-containing (Paraguard); and levonorgestrel (LNG)-containing (Mirena, Liletta, Kyleena and Skyla).
- Paraguard = 10 years
- 52mg LNG: Mirena 5 years; Liletta 3 years (5 y approval pending).
- 19.5mg LNG: Kyleena 5 years
- 13.5mg LNG: Skyla 3 years
- Subdermal hormonal implant: Nexplanon
- 20x as effective as OCPs, patch or ring!
- Young women (<21yo) -> 2x failure rate with OCP, patch, ring; but no increased failure with LARC.
MECHANISM OF IUDs:
- LARCs do NOT abort a fertilized, implanted embryo.
- Cu – toxic to sperm
- LNG – suppresses ovulation and thickens cervical mucus
EFFICACY OF IUDs:
- < 1% pregnancy in the first year of use
- LNG – 0.1-0.2%
- Cu -0.5-0.8%
CONTINUATION RATES OF IUDs:
- 85-88% at 1 year; 80% at 2 years; 52-56% at 5 years.
CONTRAINDICATIONS TO IUD USE:
- Current pelvic infection or STD (if IUD already in, leave it in and treat the STD)
- Current gyn cancer
- Current or recent breast CA (avoidance recommended though evidence unclear)
- If pt screened according to CDC guidelines (e.g., yearly GC/chlam for pts <25yo), no extra screening needed prior to insertion.
CAUTIONS AND EDUCATION RE IUD USE:
- Cu IUD likely to increase menstrual bleeding
- LNG IUD likely to decrease menstrual bleeding
- All IUDs likely to cause some irregular, spotty bleeding
- Cu IUD can be used as emergency contraception placed after intercourse
HORMONAL IMPLANT (Nexplanon in US)
MECHANISM OF NEXPLANON:
- Etonorgestrol secretion
- Decreases ovulation
- Thickens cervical mucus
- 0.1% pregnancy at 1 year (independent of BMI)
- 82% continuation at one year
- Current or recent breast cancer (recommendation, but evidence unclear)
- Irregular bleeding, spotting common
- Amenorrhea achieved in about 20%
LARC USE IN SPECIFIC POPULATIONS:
- PID: low risk, <1% even without STD screening prior to insertion
- LNG may protect against pelvic infection
- Post-partum and post-abortion: safe to insert immediately, less expulsion if inserted immediately after placental delivery.
- Breast-feeding: may increase risk of perf, but unclear (5.6/1000)
- No clear effect on breastfeeding success or the breastfed infant
AREAS OF UNCERTAINTY:
Barriers to use:
- Low awareness
- Lack of trained clinicians
- Low reimbursement for procedure
- Extra steps, extra visits (unnecessary)
- Catholic healthcare systems
If STD acquired with IUD in place, leave it in and treat the STD per usual.
HIV and LNG-IUDs: Some HIV drugs (ritonavir and efavirenz) may reduce LNG levels, increasing pregnancy risk. Counsel pts accordingly.