Birth Control Implant Safety During Breastfeeding
The etonogestrel contraceptive implant (Nexplanon) is safe for breastfeeding women and can be inserted at any time postpartum, including immediately after delivery. 1
Evidence-Based Safety Profile
The contraceptive implant is explicitly approved for use in breastfeeding women by major medical organizations:
CDC guidelines classify the implant as U.S. MEC Category 1 (no restrictions) for breastfeeding women ≥1 month postpartum, meaning advantages clearly outweigh any theoretical risks 1
For breastfeeding women <1 month postpartum, the implant is U.S. MEC Category 2, meaning advantages generally outweigh theoretical risks 1
Both ACOG and CDC explicitly support immediate postpartum insertion of implants as safe and effective practice that removes barriers to contraceptive access 1, 2
Effects on Breastfeeding and Infant Health
The theoretical concern about progestin effects on lactation has been thoroughly studied:
Studies of contraceptive implant use among breastfeeding women have generally found no effects on breastfeeding performance or infant health and growth 1
A 3-year comparative study found no differences in infant growth parameters (body length, head circumference, weight) or psychomotor development between infants whose mothers used Implanon versus a non-medicated IUD 3
A 2025 randomized controlled trial comparing immediate (within 24 hours) versus delayed (≥2 weeks) postpartum implant placement found no clinically important differences in breastfeeding continuation at 8 weeks (78.3% immediate vs 78.9% delayed) 4
The FDA drug label states that small amounts of etonogestrel are transferred to breast milk, but harmful effects have not been observed in breastfed infants exposed to contraceptive hormones through breast milk 5
Important Clinical Considerations
One critical caveat exists: A single case report documented reduced weight gain in an exclusively breastfed infant following ENG implant placement at 4 weeks postpartum, with the infant dropping from the 44th to 6th percentile for growth 6. However, among 108 breastfeeding women studied, only one case of lactation failure was identified, suggesting an estimated risk of 0.9% (95% CI 0.2-5.1%) if not due to chance 6.
Practical counseling approach:
- Inform women that the implant is considered safe for breastfeeding based on extensive evidence 1, 3, 4
- Mention the rare possibility of reduced milk supply and advise monitoring infant weight gain and feeding cues 6
- Emphasize that the implant can be removed immediately if concerns arise 6
Timing and Backup Contraception
The implant can be inserted at any time postpartum if reasonably certain the woman is not pregnant 1, 7:
If the woman is <6 months postpartum, amenorrheic, and fully/nearly fully breastfeeding (≥85% of feeds), no backup contraception is needed 1
If inserted ≥21 days postpartum when menses has not returned, use backup contraception or abstain for 7 days 2, 7
Comparison to Combined Hormonal Contraceptives
Unlike the progestin-only implant, combined hormonal contraceptives (pills, patch, ring) are contraindicated during breastfeeding:
Absolutely contraindicated (U.S. MEC Category 4) for the first 3 weeks postpartum in all women due to VTE risk 2
Generally should not be used (U.S. MEC Category 3) during weeks 3-4 postpartum in breastfeeding women due to concerns about milk production 2
Combined hormonal contraceptives can reduce milk production in breastfeeding mothers, which is less likely once breastfeeding is well-established but can occur at any time 5
The progestin-only implant avoids these estrogen-related concerns entirely, making it a superior choice for breastfeeding women 1, 2.