Types of Long-acting reversible contraceptives
“the implant”, is a 4 cm long cylindrical implant that is placed under the skin of the upper arm providing a continuous release of etonogestrel 68mg for three years (Merck, 2011). The failure rate is extremely low, less than one pregnancy per 100 women in one year, but greater than 10% of women experience irregular bleeding, with the majority of women experiencing fewer than average days of bleeding, but some experiencing more (Mansour, Bahamondes, Critchley, Darney, & Fraser, 2011; Merck, 2011). The 24 month discontinuation rate in trials conducted both in the U.S. and abroad ranges from 27-75%, with the most common reason due to irregular bleeding (Arribas- Mir et al., 2009; Harvey, Seib, & Lucke, 2009; Lakha & Glasier, 2006; O’Neil-Callahan, Peipert, Zhao, Madden, & Secura, 2013). Many women express that they were not adequately warned of all side effects prior to initiation of the implant, thus side-effect counseling particularly regarding bleeding patterns is extremely important and in some studies has led to improved rates of continuation (Davie et al., 1996; Hoggart, Louise Newton, & Dickson, 2013). However, in other settings, more “intensive” counseling has had no effect (Modesto, Bahamondes, & Bahamondes, 2014). Latina, Black, White and Asian women differ in their belief that it is necessary to have a period every month with ethnic and cultural factors possibly accounting for some of the differences (Andrist et al., 2004; Mansour et al., 2011). Black women and Hispanic women were more likely to hold this belief as compared to White women which may partially account of lower usage of LARC among Black and Hispanic women (Andrist et al., 2004; Zheng, Zheng, Qian, Sang, & Kaper, 1999). As the implant is the only externally visible form of LARC, some women note concerns of privacy as it may be visible under the skin, but others report that their male partners find its appearance reassuring (Meirik, Fraser, d’ Arcangues, & WHO Consultation on Implantable Contraceptives for Women, 2003). Indonesians and Ethiopians may insert objects or herbs under the skin for beautification or medicinal purposes thus adoption of the implant may be increased in these cultures (Meirik et al., 2003) In addition to the low failure rate and the length of duration of action, the implant has other advantages, particularly regarding its insertion. The implant is more likely to be placed before an adolescent mother resumes sexual intercourse as compared to the IUD, likely due to recommendations regarding IUD placement that dictate that placement should occur within 48 hours of birth or after four weeks (Tocce, Sheeder, Python, & Teal, 2012). Implants are also advantageous over IUDs in that they can be placed after any abortion, not just abortions that occur in the first or second trimester (American Congress of Obstetricians and Gynecologists, 2012). Implants also have the potential to be administered by a wider number of specialists and generalists as they require considerably less extensive training than IUDs (Potter, Koyama, & Coles, 2015).
Three types of intrauterine devices are currently available in the United States: the ParaGard® copper IUD, the Mirena® IUD (a levonorgestrel-releasing form), and most recently the Skyla® low-dose levonorgestrel-releasing IUD (Prescott & Matthews, 2014). A fourth type of IUD, marketed as GyneFix®, a frameless copper IUD, does not differ significantly from the conventional framed IUD in any of the characteristics measured (O’Brien & Marfleet, 2005). All methods are very effective with less than one percent of women experiencing pregnancy with one year of use and are also readily reversible with 70% of women able to conceive in the year after removal (Prescott & Matthews, 2014). Adolescents and young women discontinue IUD use for a spectrum of reasons including pain, bleeding, infection, expulsion, pregnancy desire, and partner sensation of strings (Lara-Torre, Spotswood, Correia, & Weiss, 2011; Teal & Sheeder, 2012). The twelve month discontinuation rate for adolescent women is significantly higher than women over 25 years of age, with estimates ranging from 23-45% (Aoun et al., 2014; Teal & Sheeder, 2012). Rates of expulsion, contraceptive failure, and discontinuation at 12 months are all significantly increased with the copper IUD compared to the hormonal (Aoun et al., 2014). An IUD is advantageous in that it may be inserted same day post abortion, however, this leads to significantly higher expulsion rates compared to delayed insertion (Okusanya, Oduwole, & Effa, 2014). IUDs are also effective for other uses than routine contraception: the copper IUD is the most effective form of emergency contraception and hormonal IUDs are the most effective minimally invasive treatment of menorrhagia (Koyama, Hagopian, & Linden, 2013; Turok et al., 2013; American Academy of Pediatrics, 2014; Qiu, Cheng, Wang, & Hua, 2014).
Medroxyprogesterone acetate, Depo-Provera®, “the shot”, is considered a form of LARC by the National Institute of Health Care Excellence in the UK since it is a means of contraception that is administered less than once a month, but is not included by major physician groups in the United States (American Congress of Obstetricians and Gynecologists, 2012; Randel, 2012; National Collaborating Centre for Women’s and Children’s Health (UK), 2005). Medroxyprogesterone acetate is administered by a health professional as an intramuscular injection every 3 months (Pfizer, 2010). Part of the controversy over the long or short-acting classification of this method is borne out by the large difference between typical use and perfect use pregnancy rates: with typical use the 1 year pregnancy rate is 3%, but with perfect use this rate is only 0.3% and is comparable to the implant and all types of IUD (Curtis, 2010). Additionally, the shot is not currently recommended as method of contraception for greater than two years due to its risk of bone mineralization loss (Curtis, 2010). Depo-Provera® has the highest 12 and 24 month discontinuation rate of all hormonal methods of contraception, a relationship that is not significantly altered by allowing user self-injection (Curtis, 2010; OʼNeil-Callahan, Peipert, Zhao, Madden, & Secura, 2013; Cameron, Glasier, & Johnstone, 2012). The most common reason for discontinuation is irregular bleeding followed by breast tenderness and weight gain (Drey & Darney, 2002). The shot is not as readily reversible as other methods of contraception as ovulation resumes on average 200 days after the last shot (Drey & Darney, 2002). Despite these side effects, medroxyprogesterone injection is especially useful in certain patient populations such as epileptics and sickle cell patients as it has been shown to reduce seizures and decrease hemolytic crisis (Drey & Darney, 2002).