Contraceptive Implant Placement

The contraceptive implant is a popular form of long-acting reversible contraception (LARC). Norplant, the first contraceptive implant, became available in 1983 ^[1] but was later removed from the market owing to patient dissatisfaction with adverse effects that ultimately led to several lawsuits against the manufacturer. It was also difficult to remove. ^[2]

The currently available implant, Nexplanon, is a rod that contains the progestin etonogestrel and is intended for subdermal implantation in the non-dominant arm. It is the second-generation of the device; the first-generation was called Implanon. The currently available device differs from its first-generation counterpart in that the implant itself is radiopaque and its applicator design is improved so as to prevent placement deeper than the intended subdermal location.

The advantage of an implantable form of contraception is that it provides effective long-term contraception that does not depend on the recipient’s daily compliance. The implant has become a popular choice among adolescents and young women, and is appropriate for both nulliparous or parous women. ^[3]

The most recent generation of implantable devices is the most effective form of birth control available and can usually be inserted by trained practitioners in less than one minute. ^{[4, 5, 6, 7]} The pregnancy rate with the implant is 0.05%, which is slightly lower than the levonorgestrel intrauterine device (0.2%) and the copper intrauterine device (0.6%). ^{[8, 9]}

A release rate of 25-30 µg/day of etonogestrel is required to suppress ovulation. With this device, the initial rate of release is 60-70 µg/day, which slowly decreases over time, to about 30 µg/day. Maximum serum levels are attained the fourth day after insertion, on average.

After removal of the implant, etonogestrel serum levels become undetectable within one week. ^{[1, 6, 10]}

The contraceptive implant is currently approved for contraception in women, including nulliparous women, adolescents, and breastfeeding mothers. ^[8]  The implant is approved for immediate postpartum use. It may be inserted as soon as 10 minutes after placental delivery, thus providing safe and effective reversible contraception prior to hospital discharge. The insertion technique does not differ for immediately postpartum placement.  ^[11]

The contraceptive implant is an etonorgestrel implant, which works by the same mechanism as other progesterone-only methods: by inhibiting ovulation, thinning the endometrium, and thickening cervical mucus. ^{[5, 12]}

The US Medical Eligibility Criteria for Contraceptive Use, published by Centers for Disease Control and Prevention, guides practitioners about the safety of contraceptive implant use in patients with other medical conditions. The contraceptive implant is safe or the risks of harm are thought to be outweighed by the contraceptive benefit in the following situations ^[8] :

• Cigarette smoking

• Current infection with or history of sexually transmitted diseases or pelvic inflammatory disease

• Obesity (Note: the contraceptive implant has been studied in women up to 130% of ideal body weight; the effectiveness of the implant in obese women is still being investigated. ^{[10, 13]} )

• Hypertension

• Hyperlipidemia

• History of deep vein thrombosis or pulmonary embolism

• Rheumatoid arthritis

• Anemia

• Mild cirrhosis

• Epilepsy

• Thyroid disease

• Diabetes mellitus

• History of bariatric surgery

• Breastfeeding ^{[14, 15]}

• Postabortion (first or second trimester)

The contraceptive implant should not be used in the following situations:

• Pregnancy

• Liver disease, including severe cirrhosis or liver tumors

• Personal history of breast cancer

• Undiagnosed abnormal vaginal bleeding

• Allergy or hypersensitivity to any of the implant materials

The pregnancy rate with the implant is 0.05%, which is slightly lower than the levonorgestrel intrauterine device (0.2%) and the copper intrauterine device (0.6%). ^{[8, 9]}

Potential complications

The most common procedural complication is pain at the insertion site, which occurs in less than 3% of users, according to one study. ^[7] Pain is usually transient and resolves with time. Other uncommon complications include the implant being retained in the needle applicator, bleeding or redness at the insertion site, and hematoma formation. ^{[7, 6]} Bruising after insertion is possible and should resolve within a few days.

Side effects of the etonorgestrel implant, unrelated to implant insertion, have been reviewed in an analysis of 11 major international clinic trials that include 942 subjects. The most common reason (13.6%) for a woman to discontinue use of the implant was an adverse side effect such as headache, weight gain, acne, breast pain, emotional lability, and abdominal pain. Another 11% of women cite undesirable bleeding irregularities as their reason for discontinuation. The most common irregularity was infrequent bleeding (33.3%), followed by amenorrhea (21.4%), prolonged bleeding, and frequent bleeding. ^[7]