Currently, 1 contraceptive implant, Nexplanon, is approved in the United States. It contains 68 mg of etonogestrel and is approved for 3 years of use. The implant is inserted subdermally on the inner aspect of the upper, nondominant arm. Before inserting contraceptive implants, healthcare providers must attend a clinical training program sponsored by the manufacturer. The size of the implant is 4 cm (length) by 2 cm (diameter). The contraceptive implant is more than 99% effective at preventing pregnancies. The implant is radiopaque and can be visualized with several modalities: radiography, ultrasonography, computed tomography, and magnetic resonance imaging.10 The most common side effects of the implant are menstrual changes, especially irregular bleeding. However, irregular bleeding with the implant decreases in half of women during the first 3 months of use.11 Weight gain, another concern of patients using contraceptive methods, occurs in 6% to 12% of women using the implant.11 However, most women do not have the implant removed because of weight gain.
US medical eligibility criteria
It is important to prescribe contraceptive methods to patients according to the latest evidence. The US Medical Eligibility Criteria (US MEC) were updated in 2016. They provide evidence-based recommendations for healthcare providers to follow when determining which patients can safely use a method of contraception.12 The 2016 US Selected Practice Recommendations for Contraceptive Use (US SPR) offer guidance on how contraceptive methods can be used and on how the obstacles that patients encounter when trying to obtain and use contraceptive methods can be overcome.13 The US MEC and US SPR are available as free applications (apps) for iPhone and Android platforms and online at the Centers for Disease Control and Prevention website. In addition, the US MEC are available as a chart that can be laminated for ease of use in the clinical setting.
The US MEC comprise four categories. The methods in category 1 can be used without restriction regardless of a woman’s health condition or status. Placement in category 2 means that the advantages of the method in a woman with a specific health condition generally outweigh the risks. Placement in category 3 means that the risks of the method outweigh the benefits for a woman with a specific health condition. Methods in category 4 should not be used because they pose an unacceptable health risk. The health conditions addressed in the US MEC (https://www.cdc.gov/reproductivehealth/contraception/pdf/summary-chart-us-medical-eligibility-criteria_508tagged.pdf) include hypertension, diabetes, epilepsy, migraine headaches, and cystic fibrosis, among others. Breastfeeding status and smoking status are also considered.12
LARC in postpartum and adolescent patients
Most women can safely use the hormonal and nonhormonal IUDs, including adolescents and postpartum patients who are at high risk for unintended pregnancy. The American College of Obstetricians and Gynecologists (ACOG) Committee Opinion dated 2012 and reaffirmed in 201614 states that IUDs and implants can be safely used in teens, and IUDs can be inserted in nulliparous women. Furthermore, the ACOG recommends that providers consider LARCs as a first-line contraceptive option for most patients.4 Therefore, healthcare providers should counsel patients about LARCs and make these options available to them. According to the US MEC, the age between menarche and 20 years is a category 2 condition, whereas age 20 or older is category 1. Nulliparity is category 2, and parity is category 1.12 The postpartum period is considered to be either category 1 or category 2 for IUDs, depending on the type of IUD and the breastfeeding status of the patient.12 Similarly, there are few restrictions on the use of the implant in adolescents and postpartum patients according to the US MEC.12 Nulliparity and age between menarche and 18 years are considered category 1. For women who are not breastfeeding, the implant is category 1. If a postpartum woman is breastfeeding, the implant is category 2 until postpartum day 42, after which it is category 1.12
According to Rodriguez et al.,,15 LARCs can be offered safely to most women who are immediately postpartum. The US MEC state that nonhormonal and hormonal IUDs can be inserted less than 10 minutes after delivery of the placenta; this insertion is considered to be category 2.12 According to the ACOG, “Immediate postpartum LARC should be offered as an effective option for postpartum contraception; there are few contraindications to postpartum intrauterine devices and implants.”16 However, the expulsion rates for IUDs inserted immediately postpartum can be as high as 10% to 27%, which are higher than the expulsion rates for other IUD insertions.16 Because 40% to 57% of women have sexual intercourse before the 6-week postpartum visit, the higher expulsion rates may be offset by improved protection against pregnancy during the postpartum period.16 A repeat pregnancy may occur as early as 12 to 18 months after delivery if a woman does not start a contraceptive method.15 Therefore, postpartum LARCs may be a way to decrease the rates of unintended pregnancy in postpartum women.