According to the Los Angeles County Department of Public Health, teen births have been steadily decreasing both in Los Angeles and California over the past two decades. This is primarily due to increased use of reliable methods of contraception used by this age group. The question becomes: what is the most reliable form of contraception for teens. The Committee on Adolescent Health Care Long-Acting Reversible Contraceptive Working Group published their recommendations for contraception for teenagers in the October issue of the journal Obstetrics & Gynecology.
The researchers note that in the US, 42% of teens age 15-19 have engaged in sexual intercourse. They add that almost all sexually active adolescents report having used some method of contraception during their lifetime, they rarely select the most efficient methods. They commonly use methods with typical high use failure rates such as condoms, withdrawal, or oral contraceptives. Unintended pregnancy rates for short-acting contraceptives such as condoms, oral contraceptives, contraceptive patches, vaginal rings, and depot medroxyprogesterone acetate (DMPA) injections are 22 times higher than rates for long acting reversible contraception (LARC) such as the IUD and implants. The guidelines note that intrauterine devices (IUDs) and contraceptive implants, with their very low pregnancy rates and high rates of patient satisfaction, are the best method to prevent an unintended pregnancy in adolescent girls. Although these choices may be best for many teens, they are not suitable for all.
The authors note that the pregnancy rate among women using LARC is less than 1% per year. In addition, they cite a study published in May in The New England Journal of Medicine that reported that women younger than 21 years who were using short-acting contraceptives were twice as likely to have an unintended pregnancy as older women. In that study, with LARC, the pregnancy risk was equal for both age groups.
The recommendations note that among teens, short-acting contraceptives have much lower continuation rates than LARC methods. A study of 1,387 women aged 15 to 24 years using short-acting hormonal birth control methods reported that most were using a different contraceptive a year later. Among women who used DMPA injections, only 16% were still using that method a year later; of those using the patch, only 11% remained with that method a year later. The continuation rate was higher for vaginal rings and oral contraceptives; 30% of women using those methods were continuing with them a year later.
The authors note that a number of studies report LARC continuation rates well above 70% among teens. A 2011 study, which comprised 4,167 girls and women aged 14 to 45 years reported a 86% continuation rate for LARC after one year compared with a 55% rate for short-acting contraceptives. The study combined data from teenagers and adults; however, a study of women who used an IUD containing the hormone levonorgestrel (LNG-IUD) reported that continuation rates for women younger than 20 years were similar to those for older women; 85% of the younger group continued LNG-IUD use while 80% of the older women continued its use. Continuation rates for the copper IUD were slightly lower for teens than older women; however, the 72% continuation rate in teenagers was still far higher than reported in other studies for short-term contraception.
Despite the effectiveness of LARC, most women use short-term methods. In 2002, 2.4% of women in the US using contraception relied on a LARC method. However, the popularity of LARC is increasing. By 2009, 8.5% chose LARC; however, that percentage was higher than that reported for teens aged 15 through 19 years who were using contraceptives; according to a study published last July in Fertility and Sterility, 4.5% of teens use LARC.
The authors note that complications from IUD use are infrequent. Studies have reported that young women using IUDs have no increased risk for pelvic inflammatory disease (PID), nor are they at an increased risk for infertility.
Take home message:
Oral contraceptives are very effective for preventing pregnancy if used as directed. However, for a teen—or an older woman who misses some days, a pregnancy can occur. The report notes that the risk of PID is low with an IUD; however, its presence increases the risk of PID if a woman is exposed to a sexually transmitted disease (STD). Thus, an IUD may not be the best choice for a woman with multiple partners—or a partner with multiple partners.
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