Signs and Symptoms of Subdermal Contraceptive Implants
The most common signs and symptoms of subdermal contraceptive implants are menstrual bleeding changes (affecting up to 80% of users), including amenorrhea (22%), infrequent bleeding (34%), frequent bleeding (7%), and prolonged bleeding (18%), along with systemic effects such as weight gain (55%), acne, breast tenderness, and headache. 1, 2, 3
Menstrual Bleeding Pattern Changes
Expected Bleeding Irregularities
- Amenorrhea occurs in approximately 22% of users and is generally not harmful, requiring only reassurance rather than treatment 1, 4, 3
- Infrequent bleeding or spotting affects about 34% of women throughout implant use 5, 3
- Frequent bleeding occurs in 6.7% of users 3
- Prolonged bleeding affects 17.7% of users 3
- Unscheduled spotting or light bleeding is most common during the first year and typically decreases with continued use 1, 5
Predictive Pattern
- The bleeding pattern experienced during the first three months broadly predicts future patterns for most women 3
- Women with favorable bleeding patterns in the initial phase tend to continue with this pattern throughout the first two years 3
- Women with unfavorable initial patterns have at least a 50% chance that the pattern will improve over time 3
Systemic Adverse Effects
Common Symptoms
- Weight gain is the most frequently reported systemic side effect, affecting approximately 55% of users 2, 6, 7
- Acne is frequently reported 2, 7
- Breast tenderness is commonly experienced 2
- Headache occurs in a significant proportion of users 7
- Dizziness and mood disturbances may occur 7
- Nausea and lower abdominal pain are possible 7
- Hair loss and loss of libido have been reported 7
Beneficial Effects
- Approximately 77% of women with baseline dysmenorrhea experience complete resolution of menstrual pain symptoms 3
Local Insertion Site Effects
- Pain at the implant site may occur 7
- Neuropathy has been reported in rare cases 7
- There is a small risk of pelvic infection limited to the first 20-21 days after insertion 2
Critical Clinical Pitfalls to Avoid
When Bleeding Changes Occur
- Always rule out pregnancy if a woman's regular bleeding pattern changes abruptly to amenorrhea 4
- Systematically evaluate for pregnancy, medication interactions, sexually transmitted diseases, and new pathologic uterine conditions (polyps, fibroids) before attributing all bleeding to the implant 5
- Consider screening for STIs, particularly in adolescents, when unscheduled bleeding occurs 2
Counseling Importance
- Provide comprehensive pre-insertion counseling about expected bleeding patterns to reduce discontinuation rates 1, 2, 3
- Explain that bleeding changes are generally not harmful and may or may not decrease with continued use 1, 5
- Advise women to return at any time to discuss side effects or if they want to change methods 1
Discontinuation Rates
- Only 11.3% of patients discontinue due to bleeding irregularities, mainly because of prolonged flow and frequent irregular bleeding 3
- Approximately 9% of women stop using implants during the first year, with menstrual problems being the main reason 8
- Despite experiencing side effects, most women remove the implant only when it reaches the end of its contraceptive duration (43%) 6
Follow-Up Recommendations
- No routine follow-up visit is required after insertion 1
- At routine visits, assess satisfaction with the method, any concerns about use, and changes in health status that would affect appropriateness of continued use 1
- Consider assessing weight changes and counseling women concerned about perceived weight gain associated with their method 1