Use of the Etonogestrel-Releasing Contraceptive Implant

Jaclyn Grentzer; Colleen McNicholas; Jeffrey F Peipert


Expert Rev of Obstet Gynecol. 2013;8(4):337-344. 

In This Article

Providing The Method

Prior to insertion, contraindications to the ENG implant should be assessed by taking a detailed patient history. The risks, benefits and side effects of the implant, as well as the insertion and removal procedures, should be thoroughly explained to the patient. Structured counseling on the potential side effects of the ENG implant may improve continuation rates. In a prior study of the progestin-only method DMPA, 350 women were randomized into two groups. The study group received structured pretreatment counseling with indications about the mode of action of DMPA, the common side effects of the drug, including the possibility of irregular menstrual periods, heavy bleeding, spotting and amenorrhea. The control group received routine counseling that included routine information on the expected side effects of DMPA. Discontinuation rates were 17% (30 out of 175) and 43.4% (76 out of 175), respectively (p < 0.05), for the structured and routine counseling groups.[38] Given the similarities between potential side effects with both DMPA and the ENG implant, we believe that these results can be generalized to the population of women requesting and receiving ENG implant.

The ENG implant can be inserted at any time, as long as pregnancy can be reliably ruled out. When inserted during the first 5 days after the start of the menstrual cycle, the implant will have an almost immediate contraceptive effect. A back-up method should be used for 7 days if the implant is inserted after the first 5 days while the cervical mucus becomes viscid. It is important for the patient to use a reliable method of contraception (or abstinence) prior to implant insertion.

Providers of the ENG implant should have training on insertion, removal and management of complications associated with its use. In the USA, all clinicians who insert and remove the ENG implant must undergo a FDA-approved training session sponsored by the manufacturer in order to obtain the device. These training sessions review patient counseling, informed consent, advantages of the implant, adverse events and insertion and removal techniques.

ENG implant insertion is an office procedure performed under local anesthesia. An insertion site is identified approximately 8–10 cm proximal to the medial epicondyle of the humerus of the nondominant arm, between the biceps and triceps muscles. After injecting approximately 2 cc of local anesthetic along the planned track of rod insertion, the insertion needle is introduced into the anesthetized area of the patient's arm at an angle of approximately 30°. The applicator is then lowered to a horizontal position and advanced the entire length of the needle while tenting up the skin to prevent unnecessarily deep insertion. The purple slider is then unlocked by pushing down, and the slider is pulled back completely. Both the patient and the provider should palpate the implant immediately after insertion to verify placement of the rod. The clinician then places steri-strips or a band-aid over the incision, followed by a pressure bandage. This pressure dressing should be left in place for 24 h. A clinician who has been trained in the proper insertion technique can insert an ENG implant in less than 2–3 min.[21] Infection, hematoma and local irritation are rare complications from insertion. Women may experience temporary bruising or soreness at the insertion site.[39]

Implant removal can also be done in the office under local anesthesia. A 2- to 3-mm longitudinal incision is made through the skin at the site where the end of the rod is palpable. If a fibrous sheath has formed around the rod, the end of the implant can be mobilized using sharp dissection. Once the end of the rod is visible, it can be removed with mosquito forceps. The clinician should carefully inspect the removed implant to ensure that it is intact and removed completely.

Most family planning experts believe the ENG implant can safely be placed immediately after first or second trimester surgical abortion. Continuation rates when placed in this setting have been found to mirror those of women receiving interval placement.[40] While current labeling does not support immediate postpartum placement, studies have shown that the ENG implant is safe and effective when placed in this setting.[41,42] The provision of progestin-only contraceptive methods in the immediate postpartum period has not been shown to effect maternal hemostasis[43] or milk production in lactating women. In a study evaluating the effect of the ENG implant on lactogenesis, 35 women were randomly assigned to early insertion (1–3 days postpartum) of ENG implant and 34 to standard insertion (4–8 weeks postpartum). No differences in time to onset of lactogenesis or in incidence of lactation failure were found between the early and standard insertion groups.[44] Another study comparing immediate postpartum ENG implant to DMPA at 6 weeks postpartum showed no difference in continuation of exclusive breast feeding and normal infant growth.[42]