Etonogestrel Implant Complication – What You Need to Know

Overview

The etonogestrel implant (commonly known by the brand name Nexplanon®) is a small, flexible, single‑rod contraceptive inserted under the skin of the upper arm. It releases a low dose of the progestin etonogestrel over up to three years, providing highly effective (<99%) birth control.

Although most users experience only mild, predictable side effects (e.g., irregular bleeding), a subset develop implant‑related complications. These can range from local skin problems to systemic hormonal effects and, in rare cases, insertion‑related injuries.

Who it affects: Women ages 15–45 who choose long‑acting reversible contraception (LARC). According to a 2022 CDC report, roughly 2.1 million women in the United States use the etonogestrel implant, and about 1–3 % experience a clinically significant complication that requires medical attention.^[1]

Symptoms

Complications may present with one or more of the following signs. Not every symptom means a serious problem, but any new or worsening change warrants evaluation.

Local (at the insertion site)

• Insertion site pain or tenderness – persistent throbbing beyond the first few days.
• Swelling or lump – feeling of a nodule, often due to hematoma, granuloma, or implant migration.
• Redness, warmth, or drainage – signs of infection.
• Skin discoloration – bruising that does not fade or develops into a darker patch.
• Implant protrusion or palpable rod – the rod becomes visible or can be felt under the skin.

Systemic / Hormonal

• Irregular bleeding – spotting, prolonged bleeding, or amenorrhea.
• Weight gain – often modest (average 2–3 kg) but notable in some users.
• Headache or migraine – may worsen with hormonal fluctuations.
• Acne or oily skin.
• Mood changes – irritability, depression, or anxiety.
• Breast tenderness or enlargement.
• Decreased libido.

Rare / Serious

• Deep vein thrombosis (DVT) or pulmonary embolism (PE) – extremely rare (<0.1 %); symptoms include leg swelling, pain, shortness of breath.
• Implant migration – movement into the subclavian vein or chest wall; may cause chest pain, cough, or difficulty breathing.
• Allergic reaction – hives, swelling of lips or throat, anaphylaxis (very uncommon).

Causes and Risk Factors

Complications arise from procedural issues, individual anatomy, or the hormonal action of etonogestrel.

Procedural Causes

• Improper insertion technique – too shallow or too deep placement, failure to position the rod parallel to the skin.
• Insertion site infection – breach of sterile protocol.
• Implant fracture or breakage – occurs in <1 % of insertions, often from excessive force during removal.

Hormonal/Physiologic Causes

• Individual sensitivity to progestins – genetic variation in hormone receptors.
• Body mass index (BMI) – higher BMI may alter hormone distribution and increase risk of insertion‑site pain.
• Pre‑existing clotting disorders – increase risk of thromboembolic events.

Risk Factors

• Age < 20 or > 35 (younger teens may have higher rates of irregular bleeding).
• Smoking (especially >10 cigarettes/day) – elevates clot risk.
• History of migraines with aura.
• Previous breast cancer or estrogen‑sensitive tumors (contraindicated).
• Obesity (BMI ≥ 30 kg/m²) – may make insertion more technically challenging.

Diagnosis

Evaluation begins with a thorough history and physical exam, focusing on the arm and systemic symptoms.

Clinical Assessment

• Palpation of the implant to confirm position.
• Inspection for erythema, drainage, or skin changes.
• Blood pressure, heart rate, and assessment for signs of clotting.

Imaging Studies

• Ultrasound (high‑frequency linear probe) – first‑line to locate the rod, detect hematoma or granuloma.
• Plain radiography – the implant contains barium sulfate, visible on X‑ray if ultrasound is inconclusive.
• MRI – reserved for deep migration suspicion; safe because the implant is non‑magnetic.

Laboratory Tests (selected cases)

• Complete blood count (CBC) – assess for infection or anemia from bleeding.
• Coagulation panel (PT/INR, aPTT) – if clotting disorder suspected.
• Serum etonogestrel level – rarely needed, usually for research.

Treatment Options

Management depends on the type and severity of the complication.

Local Complications

• Infection – oral antibiotics (e.g., cephalexin 500 mg q6h for 7‑10 days) or, if abscessed, incision and drainage plus culture‑directed therapy.
• Hematoma or granuloma – observation if small; aspiration or corticosteroid injection for larger, painful lesions.
• Implant migration – surgical removal under local or general anesthesia; referral to a surgeon experienced with subdermal device retrieval.
• Implant exposure – immediate removal to prevent infection and scarring.

Systemic Hormonal Issues

• Irregular bleeding – NSAIDs for breakthrough pain, combined oral contraceptives (COC) or tranexamic acid for heavy episodes; counseling that bleeding often improves after 6‑12 months.
• Weight gain or mood changes – discuss removal and alternative contraception if symptoms impair quality of life.
• Thromboembolic event – emergency anticoagulation (e.g., low‑molecular‑weight heparin) and immediate implant removal. Follow ACC/AHA guidelines for DVT/PE management.^[2]

Removal Techniques

1. Local anesthesia at the insertion site.
2. Incision over the palpable rod, careful dissection, and extraction with a specialized removal kit.
3. Closure with steri‑strips or sutures, followed by wound care instructions.

Removal should be performed by a trained clinician within 3 years of insertion; beyond that, the rod may be more fibrotic and harder to extract.

Alternative Contraception After Complication

• Intrauterine device (IUD) – hormonal (levonorgestrel) or copper.
• Combined oral contraceptive pills (COC) – if no contraindications.
• Barrier methods (condoms, diaphragm) – for short‑term use.

Living with Etonogestrel Implant Complication

Even after treatment, patients may need ongoing strategies to maintain comfort and reproductive goals.

• Monitor the insertion site weekly for the first month after removal or intervention; note any swelling, redness, or new lumps.
• Maintain a bleeding diary if irregular bleeding persists – record duration, amount, and any associated pain.
• Adopt a balanced diet rich in iron (leafy greens, legumes) to offset menstrual blood loss.
• Stay active – gentle walking improves circulation and may reduce clot risk.
• Stress‑management techniques (mindfulness, yoga) can alleviate mood changes linked to hormonal fluctuations.
• Schedule a follow‑up visit 4–6 weeks post‑removal to ensure proper wound healing and discuss future contraception.

Prevention

Many complications are avoidable with proper practice and patient education.

• Choose an experienced provider – data show a 30 % reduction in insertion‑site complications when clinicians have performed ≥50 implants.^[3]
• Pre‑insertion screening – review medical history for clotting disorders, smoking status, and breast cancer history.
• Use sterile technique – gloves, antiseptic skin prep, and a single‑use insertion kit.
• Confirm correct placement – palpate the rod immediately after insertion; if non‑palpable, obtain a quick ultrasound.
• Educate the patient – provide written instructions on how to locate the implant, when to seek care, and a follow‑up schedule at 4–6 weeks.
• Encourage smoking cessation – reduces clot risk and improves overall wound healing.

Complications If Untreated

Leaving an implant complication unaddressed can lead to escalating problems.

• Chronic infection – may spread to deeper tissues, causing cellulitis or abscess formation.
• Implant migration – can injure neurovascular structures, cause chest pain, or lead to pulmonary embolism if the rod enters a vein.
• Severe anemia – due to persistent heavy bleeding, resulting in fatigue, dyspnea, and reduced work capacity.
• Psychological distress – ongoing mood swings or body‑image concerns can affect mental health.
• Thromboembolic events – rare but life‑threatening if DVT/PE develops unnoticed.

When to Seek Emergency Care

---

References

1. Centers for Disease Control and Prevention. Contraceptive Implant Use in the United States, 2022. CDC.gov. Accessed April 2024.
2. American College of Cardiology/American Heart Association. Guideline for the Management of Venous Thromboembolism. JACC. 2023.
3. World Health Organization. WHO Selected Practice Recommendations for Contraceptive Implants. WHO Press, 2021.
4. Mayo Clinic. Etonogestrel (Implant) Side Effects and Risks. mayo.org. Updated 2023.
5. Cleveland Clinic. Implant Removal: What to Expect. clevelandclinic.org. 2022.